如何:在设计模式下扩展控件的外观和行为

您可以通过创作您自己的自定义设计器来扩展设计时环境。 您的自定义设计器可以在用户设计控件时更改控件的外观和行为。

示例

下面的代码示例演示如何创建可扩展用户界面 (UI) 的自定义设计器来设计自定义控件。 名为 DemoControlDesigner 的设计器类附加到了 DemoControl 类,并启用了以下功能:

  • 新的 DemoControl 实例的自定义初始化;

  • 控件的 MarginPadding 属性的可视化表示形式;

  • 用于设置 Anchor 属性的鼠标和键盘交互;

  • 用于设置 Anchor 属性的智能标记接口。

备注

必须添加对设计时程序集 System.Design.dll 的引用。此程序集不包含在 .NET Framework 4 Client Profile 中。若要添加对 System.Design.dll 的引用,必须将项目的目标框架更改为“.NET Framework 4”

Imports System
Imports System.Collections
Imports System.ComponentModel
Imports System.ComponentModel.Design
Imports System.Drawing
Imports System.Drawing.Design
Imports System.Windows.Forms
Imports System.Windows.Forms.Design
Imports System.Windows.Forms.Design.Behavior

Public Class Form1
   Inherits Form
   Private demoControl1 As DemoControl
   Private demoControl2 As DemoControl

   Private components As System.ComponentModel.IContainer = Nothing

   Public Sub New()
      InitializeComponent()
    End Sub

   Protected Overrides Sub Dispose(disposing As Boolean)
      If disposing AndAlso (components IsNot Nothing) Then
         components.Dispose()
      End If
      MyBase.Dispose(disposing)
    End Sub

   <STAThread()>  _
   Shared Sub Main()
      Application.EnableVisualStyles()
      Application.Run(New Form1())
    End Sub


   Private Sub InitializeComponent()
        Me.demoControl2 = New DemoControl
        Me.demoControl1 = New DemoControl
        Me.SuspendLayout()
        '
        'demoControl2
        '
        Me.demoControl2.Anchor = System.Windows.Forms.AnchorStyles.Left
        Me.demoControl2.BackColor = System.Drawing.Color.LightBlue
        Me.demoControl2.Location = New System.Drawing.Point(116, 119)
        Me.demoControl2.Margin = New System.Windows.Forms.Padding(20)
        Me.demoControl2.Name = "demoControl2"
        Me.demoControl2.Padding = New System.Windows.Forms.Padding(20)
        Me.demoControl2.Size = New System.Drawing.Size(135, 143)
        Me.demoControl2.TabIndex = 1
        '
        'demoControl1
        '
        Me.demoControl1.BackColor = System.Drawing.Color.LightBlue
        Me.demoControl1.Location = New System.Drawing.Point(282, 31)
        Me.demoControl1.Margin = New System.Windows.Forms.Padding(10)
        Me.demoControl1.Name = "demoControl1"
        Me.demoControl1.Padding = New System.Windows.Forms.Padding(10)
        Me.demoControl1.Size = New System.Drawing.Size(268, 251)
        Me.demoControl1.TabIndex = 0
        '
        'Form1
        '
        Me.ClientSize = New System.Drawing.Size(594, 352)
        Me.Controls.Add(Me.demoControl2)
        Me.Controls.Add(Me.demoControl1)
        Me.Name = "Form1"
        Me.Padding = New System.Windows.Forms.Padding(20)
        Me.Text = "a"
        Me.ResumeLayout(False)

    End Sub

    Private Sub demoControl1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs)

    End Sub
End Class

' This control demonstrates the use of a custom designer.
<DesignerAttribute(GetType(DemoControlDesigner))>  _
Public Class DemoControl
   Inherits UserControl
   Private components As System.ComponentModel.IContainer = Nothing


   Public Sub New()
      InitializeComponent()
    End Sub


   Protected Overrides Sub Dispose(disposing As Boolean)
      If disposing AndAlso (components IsNot Nothing) Then
         components.Dispose()
      End If
      MyBase.Dispose(disposing)
    End Sub


   Private Sub InitializeComponent()
    End Sub
End Class


' This class demonstrates how to build a custom designer.
' When an instance of the associated control type is created
' in a design environment like Visual Studio, this designer
' provides custom design-time behavior.
'
' When you drop an instance of DemoControl onto a form,
' this designer creates two adorner windows: one is used
' for glyphs that represent the Margin and Padding properties
' of the control, and the other is used for glyphs that
' represent the Anchor property.
'
' The AnchorGlyph type defines an AnchorBehavior type that
' allows you to change the value of the Anchor property 
' by double-clicking on an AnchorGlyph.
'
' This designer also offers a smart tag for changing the 
' Anchor property.
<System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
Public Class DemoControlDesigner
    Inherits ControlDesigner

    ' This adorner holds the glyphs that represent the Anchor property.
    Private anchorAdorner As Adorner = Nothing

    ' This adorner holds the glyphs that represent the Margin and
    ' Padding properties.
    Private marginAndPaddingAdorner As Adorner = Nothing

    ' This defines the size of the anchor glyphs.
    Private Const glyphSize As Integer = 6

    ' This defines the size of the hit bounds for an AnchorGlyph.
    Private Const hitBoundSize As Integer = glyphSize + 4

    ' References to designer services, for convenience.
    Private changeService As IComponentChangeService = Nothing
    Private selectionService As ISelectionService = Nothing
    Private behaviorSvc As BehaviorService = Nothing

    ' This is the collection of DesignerActionLists that
    ' defines the smart tags offered on the control. 
    Private actionListColl As DesignerActionListCollection = Nothing


    Public Sub New()
    End Sub


    Protected Overrides Sub Dispose(ByVal disposing As Boolean)

        If disposing Then
            If (Me.behaviorSvc IsNot Nothing) Then
                ' Remove the adorners added by this designer from
                ' the BehaviorService.Adorners collection.
                Me.behaviorSvc.Adorners.Remove(Me.marginAndPaddingAdorner)
                Me.behaviorSvc.Adorners.Remove(Me.anchorAdorner)
            End If
        End If

        MyBase.Dispose(disposing)

    End Sub


    ' This method is where the designer initializes its state when
    ' it is created.
    Public Overrides Sub Initialize(ByVal component As IComponent)
        MyBase.Initialize(component)

        ' Connect to various designer services.
        InitializeServices()

        ' Initialize adorners.
        Me.InitializeMarginAndPaddingAdorner()
        Me.InitializeAnchorAdorner()
    End Sub

    ' This demonstrates changing the appearance of a control while
    ' it is being designed. In this case, the BackColor property is
    ' set to LightBlue. 
    Public Overrides Sub InitializeNewComponent( _
    ByVal defaultValues As IDictionary)

        MyBase.InitializeNewComponent(defaultValues)

        Dim colorPropDesc As PropertyDescriptor = _
        TypeDescriptor.GetProperties(Component)("BackColor")

        If colorPropDesc IsNot Nothing AndAlso _
           colorPropDesc.PropertyType Is GetType(Color) AndAlso _
           Not colorPropDesc.IsReadOnly AndAlso _
           colorPropDesc.IsBrowsable Then
            colorPropDesc.SetValue(Component, Color.LightBlue)
        End If
    End Sub

    ' This utility method creates an adorner for the anchor glyphs.
    ' It then creates four AnchorGlyph objects and adds them to 
    ' the adorner's Glyphs collection.
    Private Sub InitializeAnchorAdorner()
        Me.anchorAdorner = New Adorner()
        Me.behaviorSvc.Adorners.Add(Me.anchorAdorner)

        Me.anchorAdorner.Glyphs.Add(New AnchorGlyph( _
        AnchorStyles.Left, _
        Me.behaviorSvc, _
        Me.changeService, _
        Me.selectionService, _
        Me, _
        Me.anchorAdorner))

        Me.anchorAdorner.Glyphs.Add(New AnchorGlyph( _
        AnchorStyles.Top, _
        Me.behaviorSvc, _
        Me.changeService, _
        Me.selectionService, _
        Me, _
        Me.anchorAdorner))

        Me.anchorAdorner.Glyphs.Add(New AnchorGlyph( _
        AnchorStyles.Right, _
        Me.behaviorSvc, _
        Me.changeService, _
        Me.selectionService, _
        Me, _
        Me.anchorAdorner))

        Me.anchorAdorner.Glyphs.Add(New AnchorGlyph( _
        AnchorStyles.Bottom, _
        Me.behaviorSvc, _
        Me.changeService, _
        Me.selectionService, _
        Me, _
        Me.anchorAdorner))

    End Sub

    ' This utility method creates an adorner for the margin and 
    ' padding glyphs. It then creates a MarginAndPaddingGlyph and 
    ' adds it to the adorner's Glyphs collection.
    Private Sub InitializeMarginAndPaddingAdorner()

        Me.marginAndPaddingAdorner = New Adorner()
        Me.behaviorSvc.Adorners.Add(Me.marginAndPaddingAdorner)

        Me.marginAndPaddingAdorner.Glyphs.Add(New MarginAndPaddingGlyph( _
        Me.behaviorSvc, _
        Me.changeService, _
        Me.selectionService, _
        Me, _
        Me.marginAndPaddingAdorner))

    End Sub

    ' This utility method connects the designer to various services.
    ' These references are cached for convenience.
    Private Sub InitializeServices()

        ' Acquire a reference to IComponentChangeService.
        Me.changeService = GetService(GetType(IComponentChangeService))

        ' Acquire a reference to ISelectionService.
        Me.selectionService = GetService(GetType(ISelectionService))

        ' Acquire a reference to BehaviorService.
        Me.behaviorSvc = GetService(GetType(BehaviorService))

    End Sub

    ' This method creates the DesignerActionList on demand, causing
    ' smart tags to appear on the control being designed.

    Public Overrides ReadOnly Property ActionLists() As _
    DesignerActionListCollection

        Get
            If actionListColl Is Nothing Then
                actionListColl = New DesignerActionListCollection()
                actionListColl.Add(New AnchorActionList(Me.Component))
            End If

            Return actionListColl
        End Get

    End Property

    ' This class defines the smart tags that appear on the control
    ' being designed. In this case, the Anchor property appears
    ' on the smart tag and its value can be changed through a 
    ' UI Type Editor created automatically by the 
    ' DesignerActionService.

    Public Class AnchorActionList
        Inherits System.ComponentModel.Design.DesignerActionList

        ' Cache a reference to the control.
        Private relatedControl As DemoControl

        'The constructor associates the control 
        'with the smart tag list.
        Public Sub New(ByVal component As IComponent)

            MyBase.New(component)
            Me.relatedControl = component

        End Sub

        ' Properties that are targets of 
        ' DesignerActionPropertyItem entries.
        Public Property Anchor() As AnchorStyles
            Get
                Return Me.relatedControl.Anchor
            End Get
            Set(ByVal value As AnchorStyles)
                Dim pdAnchor As PropertyDescriptor = _
                TypeDescriptor.GetProperties(Me.relatedControl)("Anchor")
                pdAnchor.SetValue(Me.relatedControl, Value)
            End Set
        End Property

        ' This method creates and populates the 
        ' DesignerActionItemCollection which is used to 
        ' display smart tag items.
        Public Overrides Function GetSortedActionItems() As _
        DesignerActionItemCollection

            Dim items As New DesignerActionItemCollection()

            ' Add a descriptive header.
            items.Add(New DesignerActionHeaderItem("Anchor Styles"))

            ' Add a DesignerActionPropertyItem for the Anchor
            ' property. This will be displayed in a panel using
            ' the AnchorStyles UI Type Editor.
            items.Add(New DesignerActionPropertyItem( _
            "Anchor", _
            "Anchor Style"))

            Return items
        End Function
    End Class


#Region "Glyph Implementations"

    ' This class implements a MarginAndPaddingGlyph, which draws 
    ' borders highlighting the value of the control's Margin 
    ' property and the value of the control's Padding property.
    '
    ' This glyph has no mouse or keyboard interaction, so its
    ' related behavior class, MarginAndPaddingBehavior, has no
    ' implementation.

    Public Class MarginAndPaddingGlyph
        Inherits Glyph
        Private behaviorService As BehaviorService = Nothing
        Private changeService As IComponentChangeService = Nothing
        Private selectionService As ISelectionService = Nothing
        Private relatedDesigner As IDesigner = Nothing
        Private marginAndPaddingAdorner As Adorner = Nothing
        Private relatedControl As Control = Nothing


        Public Sub New( _
        ByVal behaviorService As BehaviorService, _
        ByVal changeService As IComponentChangeService, _
        ByVal selectionService As ISelectionService, _
        ByVal relatedDesigner As IDesigner, _
        ByVal marginAndPaddingAdorner As Adorner)

            MyBase.New(New MarginAndPaddingBehavior())
            Me.behaviorService = behaviorService
            Me.changeService = changeService
            Me.selectionService = selectionService
            Me.relatedDesigner = relatedDesigner
            Me.marginAndPaddingAdorner = marginAndPaddingAdorner

            Me.relatedControl = Me.relatedDesigner.Component

            AddHandler Me.changeService.ComponentChanged, _
            AddressOf changeService_ComponentChanged

        End Sub

        Private Sub changeService_ComponentChanged( _
        ByVal sender As Object, _
        ByVal e As ComponentChangedEventArgs)

            If Object.ReferenceEquals( _
            e.Component, _
            Me.relatedControl) Then
                If e.Member.Name = "Margin" OrElse _
                   e.Member.Name = "Padding" Then
                    Me.marginAndPaddingAdorner.Invalidate()
                End If
            End If

        End Sub

        ' This glyph has no mouse or keyboard interaction, so 
        ' GetHitTest can return null.
        Public Overrides Function GetHitTest( _
        ByVal p As Point) As Cursor
            Return Nothing
        End Function

        ' This method renders the glyph as a simple focus rectangle.
        Public Overrides Sub Paint(ByVal e As PaintEventArgs)
            ControlPaint.DrawFocusRectangle(e.Graphics, Me.Bounds)

            ControlPaint.DrawFocusRectangle( _
            e.Graphics, _
            Me.PaddingBounds)
        End Sub

        ' This glyph's Bounds property is a Rectangle defined by 
        ' the value of the control's Margin property.

        Public Overrides ReadOnly Property Bounds() As Rectangle
            Get
                Dim c As Control = Me.relatedControl
                Dim controlRect As Rectangle = _
                Me.behaviorService.ControlRectInAdornerWindow( _
                Me.relatedControl)

                Dim boundsVal As New Rectangle( _
                controlRect.Left - c.Margin.Left, _
                controlRect.Top - c.Margin.Top, _
                controlRect.Width + c.Margin.Right * 2, _
                controlRect.Height + c.Margin.Bottom * 2)

                Return boundsVal

            End Get
        End Property

        ' The PaddingBounds property is a Rectangle defined by 
        ' the value of the control's Padding property.

        Public ReadOnly Property PaddingBounds() As Rectangle
            Get
                Dim c As Control = Me.relatedControl
                Dim controlRect As Rectangle = _
                Me.behaviorService.ControlRectInAdornerWindow( _
                Me.relatedControl)

                Dim boundsVal As New Rectangle( _
                controlRect.Left + c.Padding.Left, _
                controlRect.Top + c.Padding.Top, _
                controlRect.Width - c.Padding.Right * 2, _
                controlRect.Height - c.Padding.Bottom * 2)

                Return boundsVal

            End Get
        End Property

        ' There are no keyboard or mouse behaviors associated with 
        ' this glyph, but you could add them to this class.

        Friend Class MarginAndPaddingBehavior
            Inherits System.Windows.Forms.Design.Behavior.Behavior
        End Class

    End Class

    ' This class implements an AnchorGlyph, which draws grab handles
    ' that represent the value of the control's Anchor property.
    '
    ' This glyph has mouse and keyboard interactions, which are
    ' handled by the related behavior class, AnchorBehavior.
    ' Double-clicking on an AnchorGlyph causes its value to be 
    ' toggled between enabled and disable states. 

    Public Class AnchorGlyph
        Inherits Glyph

        ' This defines the bounds of the anchor glyph.
        Protected boundsValue As Rectangle

        ' This defines the bounds used for hit testing.
        ' These bounds are typically different than the bounds 
        ' of the glyph itself.
        Protected hitBoundsValue As Rectangle

        ' This is the cursor returned if hit test is positive.
        Protected hitTestCursor As Cursor = Cursors.Hand

        ' Cache references to services that will be needed.
        Private behaviorService As BehaviorService = Nothing
        Private changeService As IComponentChangeService = Nothing
        Private selectionService As ISelectionService = Nothing

        ' Keep a reference to the designer for convenience.
        Private relatedDesigner As IDesigner = Nothing

        ' Keep a reference to the adorner for convenience.
        Private anchorAdorner As Adorner = Nothing

        ' Keep a reference to the control being designed.
        Private relatedControl As Control = Nothing

        ' This defines the AnchorStyle which this glyph represents.
        Private anchorStyle As AnchorStyles


        Public Sub New( _
        ByVal anchorStyle As AnchorStyles, _
        ByVal behaviorService As BehaviorService, _
        ByVal changeService As IComponentChangeService, _
        ByVal selectionService As ISelectionService, _
        ByVal relatedDesigner As IDesigner, _
        ByVal anchorAdorner As Adorner)

            MyBase.New(New AnchorBehavior(relatedDesigner))
            ' Cache references for convenience.
            Me.anchorStyle = anchorStyle
            Me.behaviorService = behaviorService
            Me.changeService = changeService
            Me.selectionService = selectionService
            Me.relatedDesigner = relatedDesigner
            Me.anchorAdorner = anchorAdorner

            ' Cache a reference to the control being designed.
            Me.relatedControl = Me.relatedDesigner.Component

            ' Hook the SelectionChanged event. 
            AddHandler Me.selectionService.SelectionChanged, _
            AddressOf selectionService_SelectionChanged

            ' Hook the ComponentChanged event so the anchor glyphs
            ' can correctly track the control's bounds.
            AddHandler Me.changeService.ComponentChanged, _
            AddressOf changeService_ComponentChanged

        End Sub

#Region "Overrides"

        Public Overrides ReadOnly Property Bounds() As Rectangle
            Get
                Return Me.boundsValue
            End Get
        End Property


        ' This method renders the AnchorGlyph as a filled rectangle
        ' if the glyph is enabled, or as an open rectangle if the
        ' glyph is disabled.
        Public Overrides Sub Paint(ByVal e As PaintEventArgs)
            If Me.IsEnabled Then
                Dim b As New SolidBrush(Color.Tomato)
                Try
                    e.Graphics.FillRectangle(b, Me.Bounds)
                Finally
                    b.Dispose()
                End Try
            Else
                Dim p As New Pen(Color.Tomato)
                Try
                    e.Graphics.DrawRectangle(p, Me.Bounds)
                Finally
                    p.Dispose()
                End Try
            End If
        End Sub


        ' An AnchorGlyph has keyboard and mouse interaction, so it's
        ' important to return a cursor when the mouse is located in 
        ' the glyph's hit region. When this occurs, the 
        ' AnchorBehavior becomes active.
        Public Overrides Function GetHitTest( _
        ByVal p As Point) As Cursor

            If hitBoundsValue.Contains(p) Then
                Return hitTestCursor
            End If

            Return Nothing

        End Function

#End Region

#Region "Event Handlers"


        ' The AnchorGlyph objects should mimic the resize glyphs;
        ' they should only be visible when the control is the 
        ' primary selection. The adorner is enabled when the 
        ' control is the primary selection and disabled when 
        ' it is not.
        Private Sub selectionService_SelectionChanged( _
        ByVal sender As Object, _
        ByVal e As EventArgs)

            If Object.ReferenceEquals( _
            Me.selectionService.PrimarySelection, _
            Me.relatedControl) Then
                Me.ComputeBounds()
                Me.anchorAdorner.Enabled = True
            Else
                Me.anchorAdorner.Enabled = False
            End If

        End Sub

        ' If any of several properties change, the bounds of the 
        ' AnchorGlyph must be computed again.
        Private Sub changeService_ComponentChanged( _
        ByVal sender As Object, _
        ByVal e As ComponentChangedEventArgs)

            If Object.ReferenceEquals( _
            e.Component, Me.relatedControl) Then
                If e.Member.Name = "Anchor" OrElse _
                   e.Member.Name = "Size" OrElse _
                   e.Member.Name = "Height" OrElse _
                   e.Member.Name = "Width" OrElse _
                   e.Member.Name = "Location" Then

                    ' Compute the bounds of this glyph.
                    Me.ComputeBounds()

                    ' Tell the adorner to repaint itself.
                    Me.anchorAdorner.Invalidate()

                End If
            End If
        End Sub

#End Region

#Region "Implementation"


        ' This utility method computes the position and size of 
        ' the AnchorGlyph in the Adorner window's coordinates.
        ' It also computes the hit test bounds, which are
        ' slightly larger than the glyph's bounds.
        Private Sub ComputeBounds()
            Dim translatedBounds As New Rectangle( _
            Me.behaviorService.ControlToAdornerWindow(Me.relatedControl), _
            Me.relatedControl.Size)

            If (Me.anchorStyle And AnchorStyles.Top) = AnchorStyles.Top Then
                Me.boundsValue = New Rectangle( _
                translatedBounds.X + translatedBounds.Width / 2 - glyphSize / 2, _
                translatedBounds.Y + glyphSize, _
                glyphSize, _
                glyphSize)
            End If

            If (Me.anchorStyle And AnchorStyles.Bottom) = AnchorStyles.Bottom Then
                Me.boundsValue = New Rectangle( _
                translatedBounds.X + translatedBounds.Width / 2 - glyphSize / 2, _
                translatedBounds.Bottom - 2 * glyphSize, _
                glyphSize, _
                glyphSize)
            End If

            If (Me.anchorStyle And AnchorStyles.Left) = AnchorStyles.Left Then
                Me.boundsValue = New Rectangle( _
                translatedBounds.X + glyphSize, _
                translatedBounds.Y + translatedBounds.Height / 2 - glyphSize / 2, _
                glyphSize, _
                glyphSize)
            End If

            If (Me.anchorStyle And AnchorStyles.Right) = AnchorStyles.Right Then
                Me.boundsValue = New Rectangle( _
                translatedBounds.Right - 2 * glyphSize, _
                translatedBounds.Y + translatedBounds.Height / 2 - glyphSize / 2, _
                glyphSize, _
                glyphSize)
            End If

            Me.hitBoundsValue = New Rectangle( _
            Me.Bounds.Left - hitBoundSize / 2, _
            Me.Bounds.Top - hitBoundSize / 2, _
            hitBoundSize, _
            hitBoundSize)

        End Sub

        ' This utility property determines if the AnchorGlyph is 
        ' enabled, according to the value specified by the 
        ' control's Anchor property.

        Private ReadOnly Property IsEnabled() As Boolean
            Get
                Return (Me.anchorStyle And Me.relatedControl.Anchor) = Me.anchorStyle
            End Get
        End Property

#End Region



#Region "Behavior Implementation"

        ' This Behavior specifies mouse and keyboard handling when
        ' an AnchorGlyph is active. This happens when 
        ' AnchorGlyph.GetHitTest returns a non-null value.

        Friend Class AnchorBehavior
            Inherits System.Windows.Forms.Design.Behavior.Behavior
            Private relatedDesigner As IDesigner = Nothing
            Private relatedControl As Control = Nothing


            Friend Sub New(ByVal relatedDesigner As IDesigner)
                Me.relatedDesigner = relatedDesigner
                Me.relatedControl = relatedDesigner.Component
            End Sub

            ' When you double-click on an AnchorGlyph, the value of 
            ' the control's Anchor property is toggled.
            '
            ' Note that the value of the Anchor property is not set
            ' by direct assignment. Instead, the 
            ' PropertyDescriptor.SetValue method is used. This 
            ' enables notification of the design environment, so 
            ' related events can be raised, for example, the
            ' IComponentChangeService.ComponentChanged event.
            Public Overrides Function OnMouseDoubleClick( _
            ByVal g As Glyph, _
            ByVal button As MouseButtons, _
            ByVal mouseLoc As Point) As Boolean

                MyBase.OnMouseDoubleClick(g, button, mouseLoc)

                If button = MouseButtons.Left Then
                    Dim ag As AnchorGlyph = g

                    Dim pdAnchor As PropertyDescriptor = _
                    TypeDescriptor.GetProperties(ag.relatedControl)("Anchor")

                    If ag.IsEnabled Then
                        ' The glyph is enabled. 
                        ' Clear the AnchorStyle flag to disable the Glyph.
                        pdAnchor.SetValue(ag.relatedControl, _
                        ag.relatedControl.Anchor Xor ag.anchorStyle)
                    Else
                        ' The glyph is disabled. 
                        ' Set the AnchorStyle flag to enable the Glyph.
                        pdAnchor.SetValue(ag.relatedControl, _
                        ag.relatedControl.Anchor Or ag.anchorStyle)
                    End If
                End If

                Return True

            End Function

        End Class

#End Region

    End Class

#End Region
End Class

using System;
using System.Collections;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Drawing;
using System.Drawing.Design;
using System.Windows.Forms;
using System.Windows.Forms.Design;
using System.Windows.Forms.Design.Behavior;

public class Form1 : Form
{
    private DemoControl demoControl1;
    private DemoControl demoControl2;

    private System.ComponentModel.IContainer components = null;

    public Form1()
    {
        InitializeComponent();
    }

    protected override void Dispose(bool disposing)
    {
        if (disposing && (components != null))
        {
            components.Dispose();
        }
        base.Dispose(disposing);
    }

    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.Run(new Form1());
    }

    private void InitializeComponent()
    {
        this.demoControl2 = new DemoControl();
        this.demoControl1 = new DemoControl();
        this.SuspendLayout();
        // 
        // demoControl2
        // 
        this.demoControl2.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom)
                    | System.Windows.Forms.AnchorStyles.Left)
                    | System.Windows.Forms.AnchorStyles.Right)));
        this.demoControl2.BackColor = System.Drawing.Color.LightBlue;
        this.demoControl2.Location = new System.Drawing.Point(40, 40);
        this.demoControl2.Margin = new System.Windows.Forms.Padding(20);
        this.demoControl2.Name = "demoControl2";
        this.demoControl2.Padding = new System.Windows.Forms.Padding(20);
        this.demoControl2.Size = new System.Drawing.Size(284, 177);
        this.demoControl2.TabIndex = 1;
        // 
        // demoControl1
        // 
        this.demoControl1.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom)
                    | System.Windows.Forms.AnchorStyles.Left)));
        this.demoControl1.BackColor = System.Drawing.Color.LightBlue;
        this.demoControl1.Location = new System.Drawing.Point(354, 21);
        this.demoControl1.Margin = new System.Windows.Forms.Padding(10);
        this.demoControl1.Name = "demoControl1";
        this.demoControl1.Padding = new System.Windows.Forms.Padding(10);
        this.demoControl1.Size = new System.Drawing.Size(184, 207);
        this.demoControl1.TabIndex = 0;
        // 
        // Form1
        // 
        this.ClientSize = new System.Drawing.Size(594, 352);
        this.Controls.Add(this.demoControl2);
        this.Controls.Add(this.demoControl1);
        this.Name = "Form1";
        this.Padding = new System.Windows.Forms.Padding(20);
        this.Text = "a";
        this.ResumeLayout(false);

    } 
}

// This control demonstrates the use of a custom designer.
[DesignerAttribute(typeof(DemoControlDesigner))]
public class DemoControl : UserControl
{   
    private System.ComponentModel.IContainer components = null;

    public DemoControl()
    {
        InitializeComponent();
    }

    protected override void Dispose(bool disposing)
    {
        if (disposing && (components != null))
        {
            components.Dispose();
        }
        base.Dispose(disposing);
    }

    private void InitializeComponent()
    {
        // 
        // DemoControl
        // 
        this.Name = "DemoControl";

    }
}

// This class demonstrates how to build a custom designer.
// When an instance of the associated control type is created
// in a design environment like Visual Studio, this designer
// provides custom design-time behavior.
//
// When you drop an instance of DemoControl onto a form,
// this designer creates two adorner windows: one is used
// for glyphs that represent the Margin and Padding properties
// of the control, and the other is used for glyphs that
// represent the Anchor property.
//
// The AnchorGlyph type defines an AnchorBehavior type that
// allows you to change the value of the Anchor property 
// by double-clicking on an AnchorGlyph.
//
// This designer also offers a smart tag for changing the 
// Anchor property.
[System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")] 
public class DemoControlDesigner : ControlDesigner
{
    // This adorner holds the glyphs that represent the Anchor property.
    private Adorner anchorAdorner = null;

    // This adorner holds the glyphs that represent the Margin and
    // Padding properties.
    private Adorner marginAndPaddingAdorner = null;

    // This defines the size of the anchor glyphs.
    private const int glyphSize = 6;

    // This defines the size of the hit bounds for an AnchorGlyph.
    private const int hitBoundSize = glyphSize + 4;

    // References to designer services, for convenience.
    private IComponentChangeService changeService = null;
    private ISelectionService selectionService = null;
    private BehaviorService behaviorSvc = null;

    // This is the collection of DesignerActionLists that
    // defines the smart tags offered on the control. 
    private DesignerActionListCollection actionLists = null;

    public DemoControlDesigner()
    {   
    }

    protected override void Dispose(bool disposing)
    {
        if (disposing)
        {
            if (this.behaviorSvc != null)
            {   
                // Remove the adorners added by this designer from
                // the BehaviorService.Adorners collection.
                this.behaviorSvc.Adorners.Remove(this.marginAndPaddingAdorner);
                this.behaviorSvc.Adorners.Remove(this.anchorAdorner);
            }
        }

        base.Dispose(disposing);
    }

    // This method is where the designer initializes its state when
    // it is created.
    public override void Initialize(IComponent component)
    {
        base.Initialize(component);

        // Connect to various designer services.
        InitializeServices();

        // Initialize adorners.
        this.InitializeMarginAndPaddingAdorner();
        this.InitializeAnchorAdorner();

    }

    // This demonstrates changing the appearance of a control while
    // it is being designed. In this case, the BackColor property is
    // set to LightBlue. 

    public override void InitializeNewComponent(IDictionary defaultValues)
    {
        base.InitializeNewComponent(defaultValues);

        PropertyDescriptor colorPropDesc = 
            TypeDescriptor.GetProperties(Component)["BackColor"];

        if (colorPropDesc != null &&
            colorPropDesc.PropertyType == typeof(Color) &&
            !colorPropDesc.IsReadOnly &&
            colorPropDesc.IsBrowsable)
        {
            colorPropDesc.SetValue(Component, Color.LightBlue);
        }
    }

    // This utility method creates an adorner for the anchor glyphs.
    // It then creates four AnchorGlyph objects and adds them to 
    // the adorner's Glyphs collection.
    private void InitializeAnchorAdorner()
    {
        this.anchorAdorner = new Adorner();
        this.behaviorSvc.Adorners.Add(this.anchorAdorner);

        this.anchorAdorner.Glyphs.Add(new AnchorGlyph(
            AnchorStyles.Left,
            this.behaviorSvc,
            this.changeService,
            this.selectionService,
            this,
            this.anchorAdorner)
            );

        this.anchorAdorner.Glyphs.Add(new AnchorGlyph(
            AnchorStyles.Top,
            this.behaviorSvc,
            this.changeService,
            this.selectionService,
            this,
            this.anchorAdorner)
            );

        this.anchorAdorner.Glyphs.Add(new AnchorGlyph(
            AnchorStyles.Right,
            this.behaviorSvc,
            this.changeService,
            this.selectionService,
            this,
            this.anchorAdorner)
            );

        this.anchorAdorner.Glyphs.Add(new AnchorGlyph(
            AnchorStyles.Bottom,
            this.behaviorSvc,
            this.changeService,
            this.selectionService,
            this,
            this.anchorAdorner)
            );
    }

    // This utility method creates an adorner for the margin and 
    // padding glyphs. It then creates a MarginAndPaddingGlyph and 
    // adds it to the adorner's Glyphs collection.
    private void InitializeMarginAndPaddingAdorner()
    {
        this.marginAndPaddingAdorner = new Adorner();
        this.behaviorSvc.Adorners.Add(this.marginAndPaddingAdorner);

        this.marginAndPaddingAdorner.Glyphs.Add(new MarginAndPaddingGlyph(
            this.behaviorSvc,
            this.changeService,
            this.selectionService,
            this,
            this.marginAndPaddingAdorner));
    }

    // This utility method connects the designer to various services.
    // These references are cached for convenience.
    private void InitializeServices()
    {
        // Acquire a reference to IComponentChangeService.
        this.changeService = 
            GetService(typeof(IComponentChangeService)) 
            as IComponentChangeService;

        // Acquire a reference to ISelectionService.
        this.selectionService =
            GetService(typeof(ISelectionService))
            as ISelectionService;

        // Acquire a reference to BehaviorService.
        this.behaviorSvc =
            GetService(typeof(BehaviorService))
            as BehaviorService;
    }

    // This method creates the DesignerActionList on demand, causing
    // smart tags to appear on the control being designed.
    public override DesignerActionListCollection ActionLists
    {
        get
        {
            if (null == actionLists)
            {
                actionLists = new DesignerActionListCollection();
                actionLists.Add(
                    new AnchorActionList(this.Component));
            }

            return actionLists;
        }
    }

    // This class defines the smart tags that appear on the control
    // being designed. In this case, the Anchor property appears
    // on the smart tag and its value can be changed through a 
    // UI Type Editor created automatically by the 
    // DesignerActionService.
    public class AnchorActionList :
          System.ComponentModel.Design.DesignerActionList
    {   
        // Cache a reference to the control.
        private DemoControl relatedControl;

        //The constructor associates the control 
        //with the smart tag list.
        public AnchorActionList(IComponent component): base(component)
        {
            this.relatedControl = component as DemoControl;
        }

        // Properties that are targets of DesignerActionPropertyItem entries.
        public AnchorStyles Anchor
        {
            get
            {
                return this.relatedControl.Anchor;
            }
            set
            {
                PropertyDescriptor pdAnchor = TypeDescriptor.GetProperties(this.relatedControl)["Anchor"];
                pdAnchor.SetValue(this.relatedControl, value);
            }
        }

        // This method creates and populates the 
        // DesignerActionItemCollection which is used to 
        // display smart tag items.
        public override DesignerActionItemCollection GetSortedActionItems()
        {
            DesignerActionItemCollection items = 
                new DesignerActionItemCollection();

            // Add a descriptive header.
            items.Add(new DesignerActionHeaderItem("Anchor Styles"));

            // Add a DesignerActionPropertyItem for the Anchor
            // property. This will be displayed in a panel using
            // the AnchorStyles UI Type Editor.
            items.Add(new DesignerActionPropertyItem(
                "Anchor", 
                "Anchor Style") );

            return items;
        }
    }


    #region Glyph Implementations

    // This class implements a MarginAndPaddingGlyph, which draws 
    // borders highlighting the value of the control's Margin 
    // property and the value of the control's Padding property.
    //
    // This glyph has no mouse or keyboard interaction, so its
    // related behavior class, MarginAndPaddingBehavior, has no
    // implementation.

    public class MarginAndPaddingGlyph : Glyph
    {
        private BehaviorService behaviorService = null;
        private IComponentChangeService changeService = null;
        private ISelectionService selectionService = null;
        private IDesigner relatedDesigner = null;
        private Adorner marginAndPaddingAdorner = null;
        private Control relatedControl = null;

        public MarginAndPaddingGlyph(
            BehaviorService behaviorService,
            IComponentChangeService changeService,
            ISelectionService selectionService,
            IDesigner relatedDesigner,
            Adorner marginAndPaddingAdorner)
            : base(new MarginAndPaddingBehavior())
        {
            this.behaviorService = behaviorService;
            this.changeService = changeService;
            this.selectionService = selectionService;
            this.relatedDesigner = relatedDesigner;
            this.marginAndPaddingAdorner = marginAndPaddingAdorner;

            this.relatedControl = 
                this.relatedDesigner.Component as Control;

            this.changeService.ComponentChanged += new ComponentChangedEventHandler(changeService_ComponentChanged);
        }

        void changeService_ComponentChanged(object sender, ComponentChangedEventArgs e)
        {
            if (object.ReferenceEquals(
                e.Component, 
                this.relatedControl))
            {
                if (e.Member.Name == "Margin" ||
                    e.Member.Name == "Padding" )
                {
                    this.marginAndPaddingAdorner.Invalidate();
                }
            }
        }

        // This glyph has no mouse or keyboard interaction, so 
        // GetHitTest can return null.
        public override Cursor GetHitTest(Point p)
        {
            return null;
        }

        // This method renders the glyph as a simple focus rectangle.
        public override void Paint(PaintEventArgs e)
        {   
            ControlPaint.DrawFocusRectangle(
                    e.Graphics,
                    this.Bounds);

            ControlPaint.DrawFocusRectangle(
                    e.Graphics,
                    this.PaddingBounds);
        }

        // This glyph's Bounds property is a Rectangle defined by 
        // the value of the control's Margin property.
        public override Rectangle Bounds
        {
            get
            {
                Control c = this.relatedControl;
                Rectangle controlRect = 
                    this.behaviorService.ControlRectInAdornerWindow(this.relatedControl);

                Rectangle boundsVal = new Rectangle(
                    controlRect.Left - c.Margin.Left,
                    controlRect.Top - c.Margin.Top,
                    controlRect.Width + c.Margin.Right*2,
                    controlRect.Height + c.Margin.Bottom*2);

                return boundsVal;
            }
        }

        // The PaddingBounds property is a Rectangle defined by 
        // the value of the control's Padding property.
        public Rectangle PaddingBounds
        {
            get
            {
                Control c = this.relatedControl;
                Rectangle controlRect =
                    this.behaviorService.ControlRectInAdornerWindow(this.relatedControl);

                Rectangle boundsVal = new Rectangle(
                    controlRect.Left + c.Padding.Left,
                    controlRect.Top + c.Padding.Top,
                    controlRect.Width - c.Padding.Right * 2,
                    controlRect.Height - c.Padding.Bottom * 2);

                return boundsVal;
            }
        }

        // There are no keyboard or mouse behaviors associated with 
        // this glyph, but you could add them to this class.
        internal class MarginAndPaddingBehavior : Behavior
        {

        }
    }

    // This class implements an AnchorGlyph, which draws grab handles
    // that represent the value of the control's Anchor property.
    //
    // This glyph has mouse and keyboard interactions, which are
    // handled by the related behavior class, AnchorBehavior.
    // Double-clicking on an AnchorGlyph causes its value to be 
    // toggled between enabled and disable states. 

    public class AnchorGlyph : Glyph
    {
        // This defines the bounds of the anchor glyph.
        protected Rectangle boundsValue;

        // This defines the bounds used for hit testing.
        // These bounds are typically different than the bounds 
        // of the glyph itself.
        protected Rectangle hitBoundsValue;

        // This is the cursor returned if hit test is positive.
        protected Cursor hitTestCursor = Cursors.Hand;

        // Cache references to services that will be needed.
        private BehaviorService behaviorService = null;
        private IComponentChangeService changeService = null;
        private ISelectionService selectionService = null;

        // Keep a reference to the designer for convenience.
        private IDesigner relatedDesigner = null;

        // Keep a reference to the adorner for convenience.
        private Adorner anchorAdorner = null;

        // Keep a reference to the control being designed.
        private Control relatedControl = null;

        // This defines the AnchorStyle which this glyph represents.
        private AnchorStyles anchorStyle;

        public AnchorGlyph(
            AnchorStyles anchorStyle,
            BehaviorService behaviorService,
            IComponentChangeService changeService,
            ISelectionService selectionService,
            IDesigner relatedDesigner,
            Adorner anchorAdorner)
            : base(new AnchorBehavior(relatedDesigner))
        {   
            // Cache references for convenience.
            this.anchorStyle = anchorStyle;
            this.behaviorService = behaviorService;
            this.changeService = changeService;
            this.selectionService = selectionService;
            this.relatedDesigner = relatedDesigner;
            this.anchorAdorner = anchorAdorner;

            // Cache a reference to the control being designed.
            this.relatedControl = 
                this.relatedDesigner.Component as Control;

            // Hook the SelectionChanged event. 
            this.selectionService.SelectionChanged += 
                new EventHandler(selectionService_SelectionChanged);

            // Hook the ComponentChanged event so the anchor glyphs
            // can correctly track the control's bounds.
            this.changeService.ComponentChanged += 
                new ComponentChangedEventHandler(changeService_ComponentChanged);
        }

        #region Overrides

        public override Rectangle Bounds
        {
            get
            {
                return this.boundsValue;
            }
        }

        // This method renders the AnchorGlyph as a filled rectangle
        // if the glyph is enabled, or as an open rectangle if the
        // glyph is disabled.
        public override void Paint(PaintEventArgs e)
        {
            if (this.IsEnabled)
            {
                using (Brush b = new SolidBrush(Color.Tomato))
                {
                    e.Graphics.FillRectangle(b, this.Bounds);
                }
            }
            else
            {
                using (Pen p = new Pen(Color.Tomato))
                {
                    e.Graphics.DrawRectangle(p, this.Bounds);
                }
            }
        }

        // An AnchorGlyph has keyboard and mouse interaction, so it's
        // important to return a cursor when the mouse is located in 
        // the glyph's hit region. When this occurs, the 
        // AnchorBehavior becomes active.

        public override Cursor GetHitTest(Point p)
        {
            if (hitBoundsValue.Contains(p))
            {
                return hitTestCursor;
            }

            return null;
        }

        #endregion 

        #region Event Handlers

        // The AnchorGlyph objects should mimic the resize glyphs;
        // they should only be visible when the control is the 
        // primary selection. The adorner is enabled when the 
        // control is the primary selection and disabled when 
        // it is not.

        void selectionService_SelectionChanged(object sender, EventArgs e)
        {
            if (object.ReferenceEquals(
                this.selectionService.PrimarySelection,
                this.relatedControl))
            {
                this.ComputeBounds();
                this.anchorAdorner.Enabled = true;
            }
            else
            {
                this.anchorAdorner.Enabled = false;
            }
        }

        // If any of several properties change, the bounds of the 
        // AnchorGlyph must be computed again.
        void changeService_ComponentChanged(
            object sender, 
            ComponentChangedEventArgs e)
        {
            if (object.ReferenceEquals(
                e.Component,
                this.relatedControl))
            {
                if (e.Member.Name == "Anchor" ||
                    e.Member.Name == "Size" ||
                    e.Member.Name == "Height" ||
                    e.Member.Name == "Width" ||
                    e.Member.Name == "Location")
                {
                    // Compute the bounds of this glyph.
                    this.ComputeBounds();

                    // Tell the adorner to repaint itself.
                    this.anchorAdorner.Invalidate();
                }
            }
        }

        #endregion

        #region Implementation

        // This utility method computes the position and size of 
        // the AnchorGlyph in the Adorner window's coordinates.
        // It also computes the hit test bounds, which are
        // slightly larger than the glyph's bounds.
        private void ComputeBounds()
        {
            Rectangle translatedBounds = new Rectangle(
                this.behaviorService.ControlToAdornerWindow(this.relatedControl),
                this.relatedControl.Size);

            if ((this.anchorStyle & AnchorStyles.Top) == AnchorStyles.Top)
            {
                this.boundsValue = new Rectangle(
                    translatedBounds.X + (translatedBounds.Width / 2) - (glyphSize / 2),
                    translatedBounds.Y + glyphSize,
                    glyphSize,
                    glyphSize);
            }
            if ((this.anchorStyle & AnchorStyles.Bottom) == AnchorStyles.Bottom)
            {
                this.boundsValue = new Rectangle(
                    translatedBounds.X + (translatedBounds.Width / 2) - (glyphSize / 2),
                    translatedBounds.Bottom - 2*glyphSize,
                    glyphSize,
                    glyphSize);
            }
            if ((this.anchorStyle & AnchorStyles.Left) == AnchorStyles.Left)
            {
                this.boundsValue = new Rectangle(
                    translatedBounds.X + glyphSize,
                    translatedBounds.Y + (translatedBounds.Height / 2) - (glyphSize / 2),
                    glyphSize,
                    glyphSize);
            }
            if ((this.anchorStyle & AnchorStyles.Right) == AnchorStyles.Right)
            {
                this.boundsValue = new Rectangle(
                    translatedBounds.Right - 2*glyphSize,
                    translatedBounds.Y + (translatedBounds.Height / 2) - (glyphSize / 2),
                    glyphSize,
                    glyphSize);
            }

            this.hitBoundsValue = new Rectangle(
                this.Bounds.Left - hitBoundSize / 2,
                this.Bounds.Top - hitBoundSize / 2,
                hitBoundSize,
                hitBoundSize );
        }

        // This utility property determines if the AnchorGlyph is 
        // enabled, according to the value specified by the 
        // control's Anchor property.
        private bool IsEnabled
        {
            get
            {
                return 
                    ((this.anchorStyle & this.relatedControl.Anchor) == 
                    this.anchorStyle);
            }
        }

        #endregion 




        #region Behavior Implementation


        // This Behavior specifies mouse and keyboard handling when
        // an AnchorGlyph is active. This happens when 
        // AnchorGlyph.GetHitTest returns a non-null value.
        internal class AnchorBehavior : Behavior
        {
            private IDesigner relatedDesigner = null;
            private Control relatedControl = null;

            internal AnchorBehavior(IDesigner relatedDesigner)
            {
                this.relatedDesigner = relatedDesigner;
                this.relatedControl = relatedDesigner.Component as Control;
            }

            // When you double-click on an AnchorGlyph, the value of 
            // the control's Anchor property is toggled.
            //
            // Note that the value of the Anchor property is not set
            // by direct assignment. Instead, the 
            // PropertyDescriptor.SetValue method is used. This 
            // enables notification of the design environment, so 
            // related events can be raised, for example, the
            // IComponentChangeService.ComponentChanged event.

            public override bool OnMouseDoubleClick(
                Glyph g, 
                MouseButtons button, 
                Point mouseLoc)
            {
                base.OnMouseDoubleClick(g, button, mouseLoc);

                if (button == MouseButtons.Left)
                {
                    AnchorGlyph ag = g as AnchorGlyph;
                    PropertyDescriptor pdAnchor = 
                        TypeDescriptor.GetProperties(ag.relatedControl)["Anchor"];

                    if (ag.IsEnabled)
                    {
                        // The glyph is enabled. 
                        // Clear the AnchorStyle flag to disable the Glyph.
                        pdAnchor.SetValue(
                            ag.relatedControl, 
                            ag.relatedControl.Anchor ^ ag.anchorStyle );
                    }
                    else
                    {
                        // The glyph is disabled. 
                        // Set the AnchorStyle flag to enable the Glyph.
                        pdAnchor.SetValue(
                            ag.relatedControl,
                            ag.relatedControl.Anchor | ag.anchorStyle);
                    }

                }

                return true;
            }
        }


        #endregion
    }
    #endregion
}

DemoControl 类是从 UserControl 类派生的,但它不需要特别的逻辑来扩展其设计时 UI。 设计时 UI 是由 DemoControlDesigner 类实现的。

DemoControlDesigner 类使用 GlyphBehaviorAdorner 类来扩展 DemoControl 的设计时体验。 扩展的 UI 的可视方面是使用 GlyphAdorner 类实现的。 鼠标和键盘交互是在 Behavior 类中实现的。

通过只重写 ControlDesigner 方法(如 OnPaintAdornmentsOnMouseEnter),您可以扩展设计器的设计时外观和行为,但 Glyph 类提供了一种在设计器外部构建外观和行为逻辑的简便方法。

扩展外观

通过实现 Glyph 类来扩展您的自定义设计 UI 的外观。 MarginAndPaddingGlyph 类是从 Glyph 类派生的。 它绘制了两个矩形,分别表示控件的 MarginPadding 属性的值。 当控件的 MarginPadding 属性更改时,MarginAndPaddingGlyph 类处理 ComponentChanged 事件以更新显示。

下面的代码示例演示如何实现从 Glyph 派生的 MarginAndPaddingGlyph 类。

' This class implements a MarginAndPaddingGlyph, which draws 
' borders highlighting the value of the control's Margin 
' property and the value of the control's Padding property.
'
' This glyph has no mouse or keyboard interaction, so its
' related behavior class, MarginAndPaddingBehavior, has no
' implementation.

Public Class MarginAndPaddingGlyph
    Inherits Glyph
    Private behaviorService As BehaviorService = Nothing
    Private changeService As IComponentChangeService = Nothing
    Private selectionService As ISelectionService = Nothing
    Private relatedDesigner As IDesigner = Nothing
    Private marginAndPaddingAdorner As Adorner = Nothing
    Private relatedControl As Control = Nothing


    Public Sub New( _
    ByVal behaviorService As BehaviorService, _
    ByVal changeService As IComponentChangeService, _
    ByVal selectionService As ISelectionService, _
    ByVal relatedDesigner As IDesigner, _
    ByVal marginAndPaddingAdorner As Adorner)

        MyBase.New(New MarginAndPaddingBehavior())
        Me.behaviorService = behaviorService
        Me.changeService = changeService
        Me.selectionService = selectionService
        Me.relatedDesigner = relatedDesigner
        Me.marginAndPaddingAdorner = marginAndPaddingAdorner

        Me.relatedControl = Me.relatedDesigner.Component

        AddHandler Me.changeService.ComponentChanged, _
        AddressOf changeService_ComponentChanged

    End Sub

    Private Sub changeService_ComponentChanged( _
    ByVal sender As Object, _
    ByVal e As ComponentChangedEventArgs)

        If Object.ReferenceEquals( _
        e.Component, _
        Me.relatedControl) Then
            If e.Member.Name = "Margin" OrElse _
               e.Member.Name = "Padding" Then
                Me.marginAndPaddingAdorner.Invalidate()
            End If
        End If

    End Sub

    ' This glyph has no mouse or keyboard interaction, so 
    ' GetHitTest can return null.
    Public Overrides Function GetHitTest( _
    ByVal p As Point) As Cursor
        Return Nothing
    End Function

    ' This method renders the glyph as a simple focus rectangle.
    Public Overrides Sub Paint(ByVal e As PaintEventArgs)
        ControlPaint.DrawFocusRectangle(e.Graphics, Me.Bounds)

        ControlPaint.DrawFocusRectangle( _
        e.Graphics, _
        Me.PaddingBounds)
    End Sub

    ' This glyph's Bounds property is a Rectangle defined by 
    ' the value of the control's Margin property.

    Public Overrides ReadOnly Property Bounds() As Rectangle
        Get
            Dim c As Control = Me.relatedControl
            Dim controlRect As Rectangle = _
            Me.behaviorService.ControlRectInAdornerWindow( _
            Me.relatedControl)

            Dim boundsVal As New Rectangle( _
            controlRect.Left - c.Margin.Left, _
            controlRect.Top - c.Margin.Top, _
            controlRect.Width + c.Margin.Right * 2, _
            controlRect.Height + c.Margin.Bottom * 2)

            Return boundsVal

        End Get
    End Property

    ' The PaddingBounds property is a Rectangle defined by 
    ' the value of the control's Padding property.

    Public ReadOnly Property PaddingBounds() As Rectangle
        Get
            Dim c As Control = Me.relatedControl
            Dim controlRect As Rectangle = _
            Me.behaviorService.ControlRectInAdornerWindow( _
            Me.relatedControl)

            Dim boundsVal As New Rectangle( _
            controlRect.Left + c.Padding.Left, _
            controlRect.Top + c.Padding.Top, _
            controlRect.Width - c.Padding.Right * 2, _
            controlRect.Height - c.Padding.Bottom * 2)

            Return boundsVal

        End Get
    End Property

    ' There are no keyboard or mouse behaviors associated with 
    ' this glyph, but you could add them to this class.

    Friend Class MarginAndPaddingBehavior
        Inherits System.Windows.Forms.Design.Behavior.Behavior
    End Class

End Class
// This class implements a MarginAndPaddingGlyph, which draws 
// borders highlighting the value of the control's Margin 
// property and the value of the control's Padding property.
//
// This glyph has no mouse or keyboard interaction, so its
// related behavior class, MarginAndPaddingBehavior, has no
// implementation.

public class MarginAndPaddingGlyph : Glyph
{
    private BehaviorService behaviorService = null;
    private IComponentChangeService changeService = null;
    private ISelectionService selectionService = null;
    private IDesigner relatedDesigner = null;
    private Adorner marginAndPaddingAdorner = null;
    private Control relatedControl = null;

    public MarginAndPaddingGlyph(
        BehaviorService behaviorService,
        IComponentChangeService changeService,
        ISelectionService selectionService,
        IDesigner relatedDesigner,
        Adorner marginAndPaddingAdorner)
        : base(new MarginAndPaddingBehavior())
    {
        this.behaviorService = behaviorService;
        this.changeService = changeService;
        this.selectionService = selectionService;
        this.relatedDesigner = relatedDesigner;
        this.marginAndPaddingAdorner = marginAndPaddingAdorner;

        this.relatedControl = 
            this.relatedDesigner.Component as Control;

        this.changeService.ComponentChanged += new ComponentChangedEventHandler(changeService_ComponentChanged);
    }

    void changeService_ComponentChanged(object sender, ComponentChangedEventArgs e)
    {
        if (object.ReferenceEquals(
            e.Component, 
            this.relatedControl))
        {
            if (e.Member.Name == "Margin" ||
                e.Member.Name == "Padding" )
            {
                this.marginAndPaddingAdorner.Invalidate();
            }
        }
    }

    // This glyph has no mouse or keyboard interaction, so 
    // GetHitTest can return null.
    public override Cursor GetHitTest(Point p)
    {
        return null;
    }

    // This method renders the glyph as a simple focus rectangle.
    public override void Paint(PaintEventArgs e)
    {   
        ControlPaint.DrawFocusRectangle(
                e.Graphics,
                this.Bounds);

        ControlPaint.DrawFocusRectangle(
                e.Graphics,
                this.PaddingBounds);
    }

    // This glyph's Bounds property is a Rectangle defined by 
    // the value of the control's Margin property.
    public override Rectangle Bounds
    {
        get
        {
            Control c = this.relatedControl;
            Rectangle controlRect = 
                this.behaviorService.ControlRectInAdornerWindow(this.relatedControl);

            Rectangle boundsVal = new Rectangle(
                controlRect.Left - c.Margin.Left,
                controlRect.Top - c.Margin.Top,
                controlRect.Width + c.Margin.Right*2,
                controlRect.Height + c.Margin.Bottom*2);

            return boundsVal;
        }
    }

    // The PaddingBounds property is a Rectangle defined by 
    // the value of the control's Padding property.
    public Rectangle PaddingBounds
    {
        get
        {
            Control c = this.relatedControl;
            Rectangle controlRect =
                this.behaviorService.ControlRectInAdornerWindow(this.relatedControl);

            Rectangle boundsVal = new Rectangle(
                controlRect.Left + c.Padding.Left,
                controlRect.Top + c.Padding.Top,
                controlRect.Width - c.Padding.Right * 2,
                controlRect.Height - c.Padding.Bottom * 2);

            return boundsVal;
        }
    }

    // There are no keyboard or mouse behaviors associated with 
    // this glyph, but you could add them to this class.
    internal class MarginAndPaddingBehavior : Behavior
    {

    }
}

扩展行为

通过实现 Behavior 类来扩展您的自定义设计 UI 的行为。 Behavior 类从属于 Glyph 类。

警告

设计环境不允许未附加到 Glyph 对象的 Behavior 对象。

在您的 Glyph 类型的构造函数中将 Behavior 对象附加到 Glyph 对象。

下面的代码示例演示如何实现 AnchorGlyph 构造函数。

Public Sub New( _
ByVal anchorStyle As AnchorStyles, _
ByVal behaviorService As BehaviorService, _
ByVal changeService As IComponentChangeService, _
ByVal selectionService As ISelectionService, _
ByVal relatedDesigner As IDesigner, _
ByVal anchorAdorner As Adorner)

    MyBase.New(New AnchorBehavior(relatedDesigner))
    ' Cache references for convenience.
    Me.anchorStyle = anchorStyle
    Me.behaviorService = behaviorService
    Me.changeService = changeService
    Me.selectionService = selectionService
    Me.relatedDesigner = relatedDesigner
    Me.anchorAdorner = anchorAdorner

    ' Cache a reference to the control being designed.
    Me.relatedControl = Me.relatedDesigner.Component

    ' Hook the SelectionChanged event. 
    AddHandler Me.selectionService.SelectionChanged, _
    AddressOf selectionService_SelectionChanged

    ' Hook the ComponentChanged event so the anchor glyphs
    ' can correctly track the control's bounds.
    AddHandler Me.changeService.ComponentChanged, _
    AddressOf changeService_ComponentChanged

End Sub
public AnchorGlyph(
    AnchorStyles anchorStyle,
    BehaviorService behaviorService,
    IComponentChangeService changeService,
    ISelectionService selectionService,
    IDesigner relatedDesigner,
    Adorner anchorAdorner)
    : base(new AnchorBehavior(relatedDesigner))
{   
    // Cache references for convenience.
    this.anchorStyle = anchorStyle;
    this.behaviorService = behaviorService;
    this.changeService = changeService;
    this.selectionService = selectionService;
    this.relatedDesigner = relatedDesigner;
    this.anchorAdorner = anchorAdorner;

    // Cache a reference to the control being designed.
    this.relatedControl = 
        this.relatedDesigner.Component as Control;

    // Hook the SelectionChanged event. 
    this.selectionService.SelectionChanged += 
        new EventHandler(selectionService_SelectionChanged);

    // Hook the ComponentChanged event so the anchor glyphs
    // can correctly track the control's bounds.
    this.changeService.ComponentChanged += 
        new ComponentChangedEventHandler(changeService_ComponentChanged);
}

AnchorGlyph 类绘制选择手柄,这些选择手柄对应于控件的 Anchor 属性的值。 当鼠标指针在您的标志符号的作用点上时,重写 GetHitTest 方法以返回 Cursor 对象。 当设计环境从您的 GetHitTest 方法接收到一个非 null 值时,它激活与您的 Glyph 关联的 Behavior 对象。

下面的代码示例演示如何实现 AnchorGlyph 类。

    ' This class implements an AnchorGlyph, which draws grab handles
    ' that represent the value of the control's Anchor property.
    '
    ' This glyph has mouse and keyboard interactions, which are
    ' handled by the related behavior class, AnchorBehavior.
    ' Double-clicking on an AnchorGlyph causes its value to be 
    ' toggled between enabled and disable states. 

    Public Class AnchorGlyph
        Inherits Glyph

        ' This defines the bounds of the anchor glyph.
        Protected boundsValue As Rectangle

        ' This defines the bounds used for hit testing.
        ' These bounds are typically different than the bounds 
        ' of the glyph itself.
        Protected hitBoundsValue As Rectangle

        ' This is the cursor returned if hit test is positive.
        Protected hitTestCursor As Cursor = Cursors.Hand

        ' Cache references to services that will be needed.
        Private behaviorService As BehaviorService = Nothing
        Private changeService As IComponentChangeService = Nothing
        Private selectionService As ISelectionService = Nothing

        ' Keep a reference to the designer for convenience.
        Private relatedDesigner As IDesigner = Nothing

        ' Keep a reference to the adorner for convenience.
        Private anchorAdorner As Adorner = Nothing

        ' Keep a reference to the control being designed.
        Private relatedControl As Control = Nothing

        ' This defines the AnchorStyle which this glyph represents.
        Private anchorStyle As AnchorStyles


        Public Sub New( _
        ByVal anchorStyle As AnchorStyles, _
        ByVal behaviorService As BehaviorService, _
        ByVal changeService As IComponentChangeService, _
        ByVal selectionService As ISelectionService, _
        ByVal relatedDesigner As IDesigner, _
        ByVal anchorAdorner As Adorner)

            MyBase.New(New AnchorBehavior(relatedDesigner))
            ' Cache references for convenience.
            Me.anchorStyle = anchorStyle
            Me.behaviorService = behaviorService
            Me.changeService = changeService
            Me.selectionService = selectionService
            Me.relatedDesigner = relatedDesigner
            Me.anchorAdorner = anchorAdorner

            ' Cache a reference to the control being designed.
            Me.relatedControl = Me.relatedDesigner.Component

            ' Hook the SelectionChanged event. 
            AddHandler Me.selectionService.SelectionChanged, _
            AddressOf selectionService_SelectionChanged

            ' Hook the ComponentChanged event so the anchor glyphs
            ' can correctly track the control's bounds.
            AddHandler Me.changeService.ComponentChanged, _
            AddressOf changeService_ComponentChanged

        End Sub

#Region "Overrides"

        Public Overrides ReadOnly Property Bounds() As Rectangle
            Get
                Return Me.boundsValue
            End Get
        End Property


        ' This method renders the AnchorGlyph as a filled rectangle
        ' if the glyph is enabled, or as an open rectangle if the
        ' glyph is disabled.
        Public Overrides Sub Paint(ByVal e As PaintEventArgs)
            If Me.IsEnabled Then
                Dim b As New SolidBrush(Color.Tomato)
                Try
                    e.Graphics.FillRectangle(b, Me.Bounds)
                Finally
                    b.Dispose()
                End Try
            Else
                Dim p As New Pen(Color.Tomato)
                Try
                    e.Graphics.DrawRectangle(p, Me.Bounds)
                Finally
                    p.Dispose()
                End Try
            End If
        End Sub


        ' An AnchorGlyph has keyboard and mouse interaction, so it's
        ' important to return a cursor when the mouse is located in 
        ' the glyph's hit region. When this occurs, the 
        ' AnchorBehavior becomes active.
        Public Overrides Function GetHitTest( _
        ByVal p As Point) As Cursor

            If hitBoundsValue.Contains(p) Then
                Return hitTestCursor
            End If

            Return Nothing

        End Function

#End Region

#Region "Event Handlers"


        ' The AnchorGlyph objects should mimic the resize glyphs;
        ' they should only be visible when the control is the 
        ' primary selection. The adorner is enabled when the 
        ' control is the primary selection and disabled when 
        ' it is not.
        Private Sub selectionService_SelectionChanged( _
        ByVal sender As Object, _
        ByVal e As EventArgs)

            If Object.ReferenceEquals( _
            Me.selectionService.PrimarySelection, _
            Me.relatedControl) Then
                Me.ComputeBounds()
                Me.anchorAdorner.Enabled = True
            Else
                Me.anchorAdorner.Enabled = False
            End If

        End Sub

        ' If any of several properties change, the bounds of the 
        ' AnchorGlyph must be computed again.
        Private Sub changeService_ComponentChanged( _
        ByVal sender As Object, _
        ByVal e As ComponentChangedEventArgs)

            If Object.ReferenceEquals( _
            e.Component, Me.relatedControl) Then
                If e.Member.Name = "Anchor" OrElse _
                   e.Member.Name = "Size" OrElse _
                   e.Member.Name = "Height" OrElse _
                   e.Member.Name = "Width" OrElse _
                   e.Member.Name = "Location" Then

                    ' Compute the bounds of this glyph.
                    Me.ComputeBounds()

                    ' Tell the adorner to repaint itself.
                    Me.anchorAdorner.Invalidate()

                End If
            End If
        End Sub

#End Region

#Region "Implementation"


        ' This utility method computes the position and size of 
        ' the AnchorGlyph in the Adorner window's coordinates.
        ' It also computes the hit test bounds, which are
        ' slightly larger than the glyph's bounds.
        Private Sub ComputeBounds()
            Dim translatedBounds As New Rectangle( _
            Me.behaviorService.ControlToAdornerWindow(Me.relatedControl), _
            Me.relatedControl.Size)

            If (Me.anchorStyle And AnchorStyles.Top) = AnchorStyles.Top Then
                Me.boundsValue = New Rectangle( _
                translatedBounds.X + translatedBounds.Width / 2 - glyphSize / 2, _
                translatedBounds.Y + glyphSize, _
                glyphSize, _
                glyphSize)
            End If

            If (Me.anchorStyle And AnchorStyles.Bottom) = AnchorStyles.Bottom Then
                Me.boundsValue = New Rectangle( _
                translatedBounds.X + translatedBounds.Width / 2 - glyphSize / 2, _
                translatedBounds.Bottom - 2 * glyphSize, _
                glyphSize, _
                glyphSize)
            End If

            If (Me.anchorStyle And AnchorStyles.Left) = AnchorStyles.Left Then
                Me.boundsValue = New Rectangle( _
                translatedBounds.X + glyphSize, _
                translatedBounds.Y + translatedBounds.Height / 2 - glyphSize / 2, _
                glyphSize, _
                glyphSize)
            End If

            If (Me.anchorStyle And AnchorStyles.Right) = AnchorStyles.Right Then
                Me.boundsValue = New Rectangle( _
                translatedBounds.Right - 2 * glyphSize, _
                translatedBounds.Y + translatedBounds.Height / 2 - glyphSize / 2, _
                glyphSize, _
                glyphSize)
            End If

            Me.hitBoundsValue = New Rectangle( _
            Me.Bounds.Left - hitBoundSize / 2, _
            Me.Bounds.Top - hitBoundSize / 2, _
            hitBoundSize, _
            hitBoundSize)

        End Sub

        ' This utility property determines if the AnchorGlyph is 
        ' enabled, according to the value specified by the 
        ' control's Anchor property.

        Private ReadOnly Property IsEnabled() As Boolean
            Get
                Return (Me.anchorStyle And Me.relatedControl.Anchor) = Me.anchorStyle
            End Get
        End Property

#End Region

    // This class implements an AnchorGlyph, which draws grab handles
    // that represent the value of the control's Anchor property.
    //
    // This glyph has mouse and keyboard interactions, which are
    // handled by the related behavior class, AnchorBehavior.
    // Double-clicking on an AnchorGlyph causes its value to be 
    // toggled between enabled and disable states. 

    public class AnchorGlyph : Glyph
    {
        // This defines the bounds of the anchor glyph.
        protected Rectangle boundsValue;

        // This defines the bounds used for hit testing.
        // These bounds are typically different than the bounds 
        // of the glyph itself.
        protected Rectangle hitBoundsValue;

        // This is the cursor returned if hit test is positive.
        protected Cursor hitTestCursor = Cursors.Hand;

        // Cache references to services that will be needed.
        private BehaviorService behaviorService = null;
        private IComponentChangeService changeService = null;
        private ISelectionService selectionService = null;

        // Keep a reference to the designer for convenience.
        private IDesigner relatedDesigner = null;

        // Keep a reference to the adorner for convenience.
        private Adorner anchorAdorner = null;

        // Keep a reference to the control being designed.
        private Control relatedControl = null;

        // This defines the AnchorStyle which this glyph represents.
        private AnchorStyles anchorStyle;

        public AnchorGlyph(
            AnchorStyles anchorStyle,
            BehaviorService behaviorService,
            IComponentChangeService changeService,
            ISelectionService selectionService,
            IDesigner relatedDesigner,
            Adorner anchorAdorner)
            : base(new AnchorBehavior(relatedDesigner))
        {   
            // Cache references for convenience.
            this.anchorStyle = anchorStyle;
            this.behaviorService = behaviorService;
            this.changeService = changeService;
            this.selectionService = selectionService;
            this.relatedDesigner = relatedDesigner;
            this.anchorAdorner = anchorAdorner;

            // Cache a reference to the control being designed.
            this.relatedControl = 
                this.relatedDesigner.Component as Control;

            // Hook the SelectionChanged event. 
            this.selectionService.SelectionChanged += 
                new EventHandler(selectionService_SelectionChanged);

            // Hook the ComponentChanged event so the anchor glyphs
            // can correctly track the control's bounds.
            this.changeService.ComponentChanged += 
                new ComponentChangedEventHandler(changeService_ComponentChanged);
        }

        #region Overrides

        public override Rectangle Bounds
        {
            get
            {
                return this.boundsValue;
            }
        }

        // This method renders the AnchorGlyph as a filled rectangle
        // if the glyph is enabled, or as an open rectangle if the
        // glyph is disabled.
        public override void Paint(PaintEventArgs e)
        {
            if (this.IsEnabled)
            {
                using (Brush b = new SolidBrush(Color.Tomato))
                {
                    e.Graphics.FillRectangle(b, this.Bounds);
                }
            }
            else
            {
                using (Pen p = new Pen(Color.Tomato))
                {
                    e.Graphics.DrawRectangle(p, this.Bounds);
                }
            }
        }

        // An AnchorGlyph has keyboard and mouse interaction, so it's
        // important to return a cursor when the mouse is located in 
        // the glyph's hit region. When this occurs, the 
        // AnchorBehavior becomes active.

        public override Cursor GetHitTest(Point p)
        {
            if (hitBoundsValue.Contains(p))
            {
                return hitTestCursor;
            }

            return null;
        }

        #endregion 

        #region Event Handlers

        // The AnchorGlyph objects should mimic the resize glyphs;
        // they should only be visible when the control is the 
        // primary selection. The adorner is enabled when the 
        // control is the primary selection and disabled when 
        // it is not.

        void selectionService_SelectionChanged(object sender, EventArgs e)
        {
            if (object.ReferenceEquals(
                this.selectionService.PrimarySelection,
                this.relatedControl))
            {
                this.ComputeBounds();
                this.anchorAdorner.Enabled = true;
            }
            else
            {
                this.anchorAdorner.Enabled = false;
            }
        }

        // If any of several properties change, the bounds of the 
        // AnchorGlyph must be computed again.
        void changeService_ComponentChanged(
            object sender, 
            ComponentChangedEventArgs e)
        {
            if (object.ReferenceEquals(
                e.Component,
                this.relatedControl))
            {
                if (e.Member.Name == "Anchor" ||
                    e.Member.Name == "Size" ||
                    e.Member.Name == "Height" ||
                    e.Member.Name == "Width" ||
                    e.Member.Name == "Location")
                {
                    // Compute the bounds of this glyph.
                    this.ComputeBounds();

                    // Tell the adorner to repaint itself.
                    this.anchorAdorner.Invalidate();
                }
            }
        }

        #endregion

        #region Implementation

        // This utility method computes the position and size of 
        // the AnchorGlyph in the Adorner window's coordinates.
        // It also computes the hit test bounds, which are
        // slightly larger than the glyph's bounds.
        private void ComputeBounds()
        {
            Rectangle translatedBounds = new Rectangle(
                this.behaviorService.ControlToAdornerWindow(this.relatedControl),
                this.relatedControl.Size);

            if ((this.anchorStyle & AnchorStyles.Top) == AnchorStyles.Top)
            {
                this.boundsValue = new Rectangle(
                    translatedBounds.X + (translatedBounds.Width / 2) - (glyphSize / 2),
                    translatedBounds.Y + glyphSize,
                    glyphSize,
                    glyphSize);
            }
            if ((this.anchorStyle & AnchorStyles.Bottom) == AnchorStyles.Bottom)
            {
                this.boundsValue = new Rectangle(
                    translatedBounds.X + (translatedBounds.Width / 2) - (glyphSize / 2),
                    translatedBounds.Bottom - 2*glyphSize,
                    glyphSize,
                    glyphSize);
            }
            if ((this.anchorStyle & AnchorStyles.Left) == AnchorStyles.Left)
            {
                this.boundsValue = new Rectangle(
                    translatedBounds.X + glyphSize,
                    translatedBounds.Y + (translatedBounds.Height / 2) - (glyphSize / 2),
                    glyphSize,
                    glyphSize);
            }
            if ((this.anchorStyle & AnchorStyles.Right) == AnchorStyles.Right)
            {
                this.boundsValue = new Rectangle(
                    translatedBounds.Right - 2*glyphSize,
                    translatedBounds.Y + (translatedBounds.Height / 2) - (glyphSize / 2),
                    glyphSize,
                    glyphSize);
            }

            this.hitBoundsValue = new Rectangle(
                this.Bounds.Left - hitBoundSize / 2,
                this.Bounds.Top - hitBoundSize / 2,
                hitBoundSize,
                hitBoundSize );
        }

        // This utility property determines if the AnchorGlyph is 
        // enabled, according to the value specified by the 
        // control's Anchor property.
        private bool IsEnabled
        {
            get
            {
                return 
                    ((this.anchorStyle & this.relatedControl.Anchor) == 
                    this.anchorStyle);
            }
        }

        #endregion 

AnchorBehavior 类实现自定义鼠标交互。 重写 Behavior 类方法(如 OnMouseEnter)来定义您的自定义 UI。

下面的代码示例演示如何实现 AnchorBehavior 类。

        ' This Behavior specifies mouse and keyboard handling when
        ' an AnchorGlyph is active. This happens when 
        ' AnchorGlyph.GetHitTest returns a non-null value.

        Friend Class AnchorBehavior
            Inherits System.Windows.Forms.Design.Behavior.Behavior
            Private relatedDesigner As IDesigner = Nothing
            Private relatedControl As Control = Nothing


            Friend Sub New(ByVal relatedDesigner As IDesigner)
                Me.relatedDesigner = relatedDesigner
                Me.relatedControl = relatedDesigner.Component
            End Sub

            ' When you double-click on an AnchorGlyph, the value of 
            ' the control's Anchor property is toggled.
            '
            ' Note that the value of the Anchor property is not set
            ' by direct assignment. Instead, the 
            ' PropertyDescriptor.SetValue method is used. This 
            ' enables notification of the design environment, so 
            ' related events can be raised, for example, the
            ' IComponentChangeService.ComponentChanged event.
            Public Overrides Function OnMouseDoubleClick( _
            ByVal g As Glyph, _
            ByVal button As MouseButtons, _
            ByVal mouseLoc As Point) As Boolean

                MyBase.OnMouseDoubleClick(g, button, mouseLoc)

                If button = MouseButtons.Left Then
                    Dim ag As AnchorGlyph = g

                    Dim pdAnchor As PropertyDescriptor = _
                    TypeDescriptor.GetProperties(ag.relatedControl)("Anchor")

                    If ag.IsEnabled Then
                        ' The glyph is enabled. 
                        ' Clear the AnchorStyle flag to disable the Glyph.
                        pdAnchor.SetValue(ag.relatedControl, _
                        ag.relatedControl.Anchor Xor ag.anchorStyle)
                    Else
                        ' The glyph is disabled. 
                        ' Set the AnchorStyle flag to enable the Glyph.
                        pdAnchor.SetValue(ag.relatedControl, _
                        ag.relatedControl.Anchor Or ag.anchorStyle)
                    End If
                End If

                Return True

            End Function

        End Class

#End Region

    End Class

        // This Behavior specifies mouse and keyboard handling when
        // an AnchorGlyph is active. This happens when 
        // AnchorGlyph.GetHitTest returns a non-null value.
        internal class AnchorBehavior : Behavior
        {
            private IDesigner relatedDesigner = null;
            private Control relatedControl = null;

            internal AnchorBehavior(IDesigner relatedDesigner)
            {
                this.relatedDesigner = relatedDesigner;
                this.relatedControl = relatedDesigner.Component as Control;
            }

            // When you double-click on an AnchorGlyph, the value of 
            // the control's Anchor property is toggled.
            //
            // Note that the value of the Anchor property is not set
            // by direct assignment. Instead, the 
            // PropertyDescriptor.SetValue method is used. This 
            // enables notification of the design environment, so 
            // related events can be raised, for example, the
            // IComponentChangeService.ComponentChanged event.

            public override bool OnMouseDoubleClick(
                Glyph g, 
                MouseButtons button, 
                Point mouseLoc)
            {
                base.OnMouseDoubleClick(g, button, mouseLoc);

                if (button == MouseButtons.Left)
                {
                    AnchorGlyph ag = g as AnchorGlyph;
                    PropertyDescriptor pdAnchor = 
                        TypeDescriptor.GetProperties(ag.relatedControl)["Anchor"];

                    if (ag.IsEnabled)
                    {
                        // The glyph is enabled. 
                        // Clear the AnchorStyle flag to disable the Glyph.
                        pdAnchor.SetValue(
                            ag.relatedControl, 
                            ag.relatedControl.Anchor ^ ag.anchorStyle );
                    }
                    else
                    {
                        // The glyph is disabled. 
                        // Set the AnchorStyle flag to enable the Glyph.
                        pdAnchor.SetValue(
                            ag.relatedControl,
                            ag.relatedControl.Anchor | ag.anchorStyle);
                    }

                }

                return true;
            }
        }

激活您的设计时用户界面

通过创建一个 Adorner 窗口并将标志符号添加到 Glyphs 集合来启用这些标志符号。 通过将您的 Adorner 窗口添加到 BehaviorServiceAdorners 集合中,激活您的自定义设计时 UI。 在您的设计器的 Initialize 方法中执行这些操作。

下面的代码示例演示如何激活您的设计时 UI。

' This method is where the designer initializes its state when
' it is created.
Public Overrides Sub Initialize(ByVal component As IComponent)
    MyBase.Initialize(component)

    ' Connect to various designer services.
    InitializeServices()

    ' Initialize adorners.
    Me.InitializeMarginAndPaddingAdorner()
    Me.InitializeAnchorAdorner()
End Sub
// This method is where the designer initializes its state when
// it is created.
public override void Initialize(IComponent component)
{
    base.Initialize(component);

    // Connect to various designer services.
    InitializeServices();

    // Initialize adorners.
    this.InitializeMarginAndPaddingAdorner();
    this.InitializeAnchorAdorner();

}
' This utility method creates an adorner for the anchor glyphs.
' It then creates four AnchorGlyph objects and adds them to 
' the adorner's Glyphs collection.
Private Sub InitializeAnchorAdorner()
    Me.anchorAdorner = New Adorner()
    Me.behaviorSvc.Adorners.Add(Me.anchorAdorner)

    Me.anchorAdorner.Glyphs.Add(New AnchorGlyph( _
    AnchorStyles.Left, _
    Me.behaviorSvc, _
    Me.changeService, _
    Me.selectionService, _
    Me, _
    Me.anchorAdorner))

    Me.anchorAdorner.Glyphs.Add(New AnchorGlyph( _
    AnchorStyles.Top, _
    Me.behaviorSvc, _
    Me.changeService, _
    Me.selectionService, _
    Me, _
    Me.anchorAdorner))

    Me.anchorAdorner.Glyphs.Add(New AnchorGlyph( _
    AnchorStyles.Right, _
    Me.behaviorSvc, _
    Me.changeService, _
    Me.selectionService, _
    Me, _
    Me.anchorAdorner))

    Me.anchorAdorner.Glyphs.Add(New AnchorGlyph( _
    AnchorStyles.Bottom, _
    Me.behaviorSvc, _
    Me.changeService, _
    Me.selectionService, _
    Me, _
    Me.anchorAdorner))

End Sub
// This utility method creates an adorner for the anchor glyphs.
// It then creates four AnchorGlyph objects and adds them to 
// the adorner's Glyphs collection.
private void InitializeAnchorAdorner()
{
    this.anchorAdorner = new Adorner();
    this.behaviorSvc.Adorners.Add(this.anchorAdorner);

    this.anchorAdorner.Glyphs.Add(new AnchorGlyph(
        AnchorStyles.Left,
        this.behaviorSvc,
        this.changeService,
        this.selectionService,
        this,
        this.anchorAdorner)
        );

    this.anchorAdorner.Glyphs.Add(new AnchorGlyph(
        AnchorStyles.Top,
        this.behaviorSvc,
        this.changeService,
        this.selectionService,
        this,
        this.anchorAdorner)
        );

    this.anchorAdorner.Glyphs.Add(new AnchorGlyph(
        AnchorStyles.Right,
        this.behaviorSvc,
        this.changeService,
        this.selectionService,
        this,
        this.anchorAdorner)
        );

    this.anchorAdorner.Glyphs.Add(new AnchorGlyph(
        AnchorStyles.Bottom,
        this.behaviorSvc,
        this.changeService,
        this.selectionService,
        this,
        this.anchorAdorner)
        );
}
' This utility method creates an adorner for the margin and 
' padding glyphs. It then creates a MarginAndPaddingGlyph and 
' adds it to the adorner's Glyphs collection.
Private Sub InitializeMarginAndPaddingAdorner()

    Me.marginAndPaddingAdorner = New Adorner()
    Me.behaviorSvc.Adorners.Add(Me.marginAndPaddingAdorner)

    Me.marginAndPaddingAdorner.Glyphs.Add(New MarginAndPaddingGlyph( _
    Me.behaviorSvc, _
    Me.changeService, _
    Me.selectionService, _
    Me, _
    Me.marginAndPaddingAdorner))

End Sub
// This utility method creates an adorner for the margin and 
// padding glyphs. It then creates a MarginAndPaddingGlyph and 
// adds it to the adorner's Glyphs collection.
private void InitializeMarginAndPaddingAdorner()
{
    this.marginAndPaddingAdorner = new Adorner();
    this.behaviorSvc.Adorners.Add(this.marginAndPaddingAdorner);

    this.marginAndPaddingAdorner.Glyphs.Add(new MarginAndPaddingGlyph(
        this.behaviorSvc,
        this.changeService,
        this.selectionService,
        this,
        this.marginAndPaddingAdorner));
}

编译代码

必须添加对设计时程序集 System.Design.dll 的引用。

当您对组件的设计时方面做更改时,您需要重新生成控件项目。 此外,如果有另外一个 Windows 窗体项目当前处于打开状态并且正在使用此组件,您可能需要刷新该项目才能看到更改。 一般情况下,需要关闭并重新打开包含组件的设计窗口。

请参见

任务

如何:向 Windows 窗体组件附加智能标记

参考

Glyph

Behavior

Adorner

其他资源

自定义设计器