如何:创建用户界面类型编辑器

下面的代码示例包含两个不同的用户界面 (UI) 类型编辑器,分别用于 如何:创建显示进度的 Windows 窗体控件 中所述的 FlashTrackBar 控件的两个属性。

在第一个示例中,FlashTrackBarValueEditor 被应用于 Value 属性,说明了以下几点:

  • FlashTrackBarValueEditor 如何扩展 UITypeEditor 类。

  • 如何重写 EditValue 方法以设置编辑器的属性。

  • 如何重写 GetEditStyle 方法以指定编辑器的样式。

在第二个示例中,FlashTrackBarDarkenByEditor 扩展 FlashTrackBarValueEditor 并重写帮助器方法以设置属性。 FlashTrackBarDarkenByEditor 被应用于 FlashTrackBar 的 DarkenBy 属性。

提示

如何:创建显示进度的 Windows 窗体控件 中所述,您必须将这些示例与 FlashTrackBar 控件一起编译。

FlashTrackBarValueEditor

Imports System
Imports System.ComponentModel
Imports System.ComponentModel.Design
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Drawing.Design
Imports System.Windows.Forms
Imports System.Diagnostics
Imports System.Windows.Forms.ComponentModel
Imports System.Windows.Forms.Design

Namespace Microsoft.Samples.WinForms.VB.FlashTrackBar

    <System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
    Public Class FlashTrackBarValueEditor
        Inherits UITypeEditor

        Private edSvc As IWindowsFormsEditorService


        Overridable Protected Sub SetEditorProps(editingInstance As FlashTrackBar, editor As FlashTrackBar)
            editor.ShowValue = true
            editor.StartColor = Color.Navy
            editor.EndColor = Color.White
            editor.ForeColor = Color.White
            editor.Min = editingInstance.Min
            editor.Max = editingInstance.Max
        End Sub

        Overrides OverLoads Public Function EditValue(context As ITypeDescriptorContext, provider As IServiceProvider, value As object) As Object

            If ((context IsNot Nothing) And (context.Instance IsNot Nothing) And (provider IsNot Nothing)) Then

                edSvc = CType(provider.GetService(GetType(IWindowsFormsEditorService)), IWindowsFormsEditorService)

                If (edSvc IsNot Nothing) Then

                    Dim trackBar As FlashTrackBar = New FlashTrackBar()
                    AddHandler trackBar.ValueChanged, AddressOf Me.ValueChanged
                    SetEditorProps(CType(context.Instance, FlashTrackBar), TrackBar)

                    Dim asInt As Boolean = True

                    If (TypeOf value Is Integer) Then
                        trackBar.Value = CInt(value)
                    ElseIf (TypeOf value Is System.Byte) Then
                        asInt = False
                        trackBar.Value = CType(value, Byte)
                    End If

                    edSvc.DropDownControl(trackBar)

                    If (asInt) Then
                        value = trackBar.Value
                    Else
                        value = CType(trackBar.Value, Byte)
                    End If

                End If

            End If

            Return value

         End Function

        Overrides OverLoads Public Function GetEditStyle(context As ITypeDescriptorContext) As UITypeEditorEditStyle
            If ((context IsNot Nothing) And (context.Instance IsNot Nothing)) Then
                Return UITypeEditorEditStyle.DropDown
            End If
            Return MyBase.GetEditStyle(context)
        End Function

        private Sub ValueChanged(sender As object, e As EventArgs)
            If (edSvc IsNot Nothing) Then
                edSvc.CloseDropDown()
            End If
        End Sub

    End Class

End Namespace
namespace Microsoft.Samples.WinForms.Cs.FlashTrackBar {
    using System;
    using System.ComponentModel;
    using System.ComponentModel.Design;
    using System.Diagnostics;
    using System.Drawing;
    using System.Drawing.Drawing2D;
    using System.Drawing.Design;
    using System.Windows.Forms;
    using System.Windows.Forms.ComponentModel;
    using System.Windows.Forms.Design;

    [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")] 
    public class FlashTrackBarValueEditor : System.Drawing.Design.UITypeEditor {

        private IWindowsFormsEditorService edSvc = null;

        protected virtual void SetEditorProps(FlashTrackBar editingInstance, FlashTrackBar editor) {
            editor.ShowValue = true;
            editor.StartColor = Color.Navy;
            editor.EndColor = Color.White;
            editor.ForeColor = Color.White;
            editor.Min = editingInstance.Min;
            editor.Max = editingInstance.Max;
        }

        public override object EditValue(ITypeDescriptorContext context, IServiceProvider provider, object value) {

            if (context != null
                && context.Instance != null
                && provider != null) {

                edSvc = (IWindowsFormsEditorService)provider.GetService(typeof(IWindowsFormsEditorService));

                if (edSvc != null) {
                    FlashTrackBar trackBar = new FlashTrackBar();
                    trackBar.ValueChanged += new EventHandler(this.ValueChanged);
                    SetEditorProps((FlashTrackBar)context.Instance, trackBar);
                    bool asInt = true;
                    if (value is int) {
                        trackBar.Value = (int)value;
                    }
                    else if (value is byte) {
                        asInt = false;
                        trackBar.Value = (byte)value;
                    }
                    edSvc.DropDownControl(trackBar);
                    if (asInt) {
                        value = trackBar.Value;
                    }
                    else {
                        value = (byte)trackBar.Value;
                    }
                }
            }

            return value;
        }

        public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext context) {
            if (context != null && context.Instance != null) {
                return UITypeEditorEditStyle.DropDown;
            }
            return base.GetEditStyle(context);
        }

        private void ValueChanged(object sender, EventArgs e) {
            if (edSvc != null) {
                edSvc.CloseDropDown();
            }
        }
    }
}

FlashTrackBarDarkenByEditor

Imports System
Imports System.ComponentModel
Imports System.ComponentModel.Design
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Drawing.Design
Imports System.Windows.Forms
Imports System.Diagnostics

Namespace Microsoft.Samples.WinForms.VB.FlashTrackBar 

   Public Class FlashTrackBarDarkenByEditor 
        Inherits FlashTrackBarValueEditor 

       Overrides Protected Sub SetEditorProps(editingInstance As FlashTrackBar, editor As FlashTrackBar) 
           MyBase.SetEditorProps(editingInstance, editor)
           editor.Min = 0
           editor.Max = System.Byte.MaxValue
       End Sub

   End Class

End Namespace
namespace Microsoft.Samples.WinForms.Cs.FlashTrackBar {
   using System;
   using System.ComponentModel;
   using System.ComponentModel.Design;
   using System.Diagnostics;
   using System.Drawing;
   using System.Drawing.Drawing2D;
   using System.Drawing.Design;
   using System.Windows.Forms;
   using System.Windows.Forms.ComponentModel;
   using System.Windows.Forms.Design;

   public class FlashTrackBarDarkenByEditor : FlashTrackBarValueEditor {
       protected override void SetEditorProps(FlashTrackBar editingInstance, FlashTrackBar editor) {
           base.SetEditorProps(editingInstance, editor);
           editor.Min = 0;
           editor.Max = byte.MaxValue;
       }
   }
}

请参见

任务

如何:实现用户界面类型编辑器

其他资源

扩展设计时支持