Walkthrough: Criando um adorno em tempo de design

Artigo
08/01/2011

This walkthrough shows how to create a design-time adorner for a Windows Presentation Foundation (WPF) custom control. You can use this adorner in the WPF Designer for Visual Studio to set the value of the Opacity property on a custom button control. For this walkthrough, the control is a simple button and the adorner is a slider that allows you to change the opacity of the button. Para obter uma listagem de código completo, consulte o exemplo de Adorno do controle deslizante de opacidade da Exemplos de extensibilidade doWPF Designer site. .

In this walkthrough, you perform the following tasks:

Create a WPF custom control library project.
Create a separate assembly for design-time metadata.
Implement the adorner provider.
Test the control at design time.

When you are finished, you will know how create an adorner provider for a custom control.

Observação
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Pré-requisitos

You need the following components to complete this walkthrough:

Visual Studio 2010.

Creating the Custom Control

The first step is to create the project for the custom control. The control is a simple button with small amount of design-time code, which uses the GetIsInDesignMode method to implement a design-time behavior.

To create the custom control

Create a new WPF Custom Control Library project in Visual Basic or Visual C# named CustomControlLibrary.

The code for CustomControl1 opens in the Code Editor.
Em Solution Explorer, altere o nome do arquivo de código para ButtonWithDesignTime.cs ou ButtonWithDesignTime.vb. If a message box appears that asks if you want to perform a rename for all references in this project, click Yes.
Open ButtonWithDesignTime.cs or ButtonWithDesignTime.vb in the Code Editor.

Replace the automatically generated code with the following code. The ButtonWithDesignTime custom control inherits from Button and displays the text "Design mode active" when the button appears in the designer. The GetIsInDesignMode check and the following design-time code are optional and shown only for demonstration.

Imports System
Imports System.Collections.Generic
Imports System.Text
Imports System.Windows.Controls
Imports System.Windows.Media
Imports System.ComponentModel

Public Class ButtonWithDesignTime
    Inherits Button

    Public Sub New()
        ' The GetIsInDesignMode check and the following design-time 
        ' code are optional and shown only for demonstration.
        If DesignerProperties.GetIsInDesignMode(Me) Then
            Content = "Design mode active"
        End If

    End Sub
End Class

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Controls;
using System.Windows.Media;
using System.ComponentModel;

namespace CustomControlLibrary
{
    public class ButtonWithDesignTime : Button
    {
        public ButtonWithDesignTime()
        {
            // The GetIsInDesignMode check and the following design-time 
            // code are optional and shown only for demonstration.
            if (DesignerProperties.GetIsInDesignMode(this))
            {
                Content = "Design mode active";
            }
        }
    }
}

Set the project's output path to "bin\".
Build the solution.

Creating the Design-time Metadata Assembly

Design-time code is deployed in special metadata assemblies. Para esta explicação passo a passo, o adorno personalizado é suportado pelo Visual Studio somente e é implantado em um assembly chamado CustomControlLibrary.VisualStudio.Design. Para obter mais informações, consulte Fornecimento de metadados de tempo de design.

To create the design-time metadata assembly

Add a new Class Library project in Visual Basic or Visual C# named CustomControlLibrary.VisualStudio.Design to the solution.
Definir o caminho de saída do projeto"... \CustomControlLibrary\bin\ ". This keeps the control's assembly and the metadata assembly in the same folder, which enables metadata discovery for designers.
Add references to the following WPF assemblies.
- PresentationCore
- PresentationFramework
- System.XAML
- WindowsBase
Referências deAdicionar a seguinte WPF Designer assemblies.
- Microsoft.Windows.Design.Extensibility
- Microsoft.Windows.Design.Interaction
Add a reference to the CustomControlLibrary project.
In Solution Explorer, change the name of the Class1 code file to Metadata.cs or Metadata.vb.

Replace the automatically generated code with the following code. This code creates an AttributeTable which attaches the custom design-time implementation to the ButtonWithDesignTime class.

Imports System
Imports System.Collections.Generic
Imports System.Text
Imports System.ComponentModel
Imports System.Windows.Media
Imports System.Windows.Controls
Imports System.Windows
Imports CustomControlLibrary
Imports Microsoft.Windows.Design.Features
Imports Microsoft.Windows.Design.Metadata

' The ProvideMetadata assembly-level attribute indicates to designers
' that this assembly contains a class that provides an attribute table. 
<Assembly: ProvideMetadata(GetType(CustomControlLibrary.VisualStudio.Design.Metadata))> 

Namespace CustomControlLibrary.VisualStudio.Design

    ' Container for any general design-time metadata to initialize.
    ' Designers look for a type in the design-time assembly that 
    ' implements IProvideAttributeTable. If found, designers instantiate
    ' this class and access its AttributeTable property automatically.
    Friend Class Metadata
        Implements IProvideAttributeTable

        ' Accessed by the designer to register any design-time metadata.
        Public ReadOnly Property AttributeTable() As AttributeTable _
            Implements IProvideAttributeTable.AttributeTable
            Get
                Dim builder As New AttributeTableBuilder()

                ' Add the adorner provider to the design-time metadata.
                builder.AddCustomAttributes(GetType(ButtonWithDesignTime), _
                                            New FeatureAttribute(GetType(OpacitySliderAdornerProvider)))

                Return builder.CreateTable()
            End Get
        End Property


    End Class

End Namespace

using System;
using System.Collections.Generic;
using System.Text;
using System.ComponentModel;
using System.Windows.Media;
using System.Windows.Controls;
using System.Windows;

using CustomControlLibrary;
using Microsoft.Windows.Design.Features;
using Microsoft.Windows.Design.Metadata;

// The ProvideMetadata assembly-level attribute indicates to designers
// that this assembly contains a class that provides an attribute table. 
[assembly: ProvideMetadata(typeof(CustomControlLibrary.VisualStudio.Design.Metadata))]
namespace CustomControlLibrary.VisualStudio.Design
{
    // Container for any general design-time metadata to initialize.
    // Designers look for a type in the design-time assembly that 
    // implements IProvideAttributeTable. If found, designers instantiate 
    // this class and access its AttributeTable property automatically.
    internal class Metadata : IProvideAttributeTable
    {
        // Accessed by the designer to register any design-time metadata.
        public AttributeTable AttributeTable
        {
            get 
            {
                AttributeTableBuilder builder = new AttributeTableBuilder();

                // Add the adorner provider to the design-time metadata.
                builder.AddCustomAttributes(
                    typeof(ButtonWithDesignTime),
                    new FeatureAttribute(typeof(OpacitySliderAdornerProvider)));

                return builder.CreateTable();
            }
        }
    }
}

Save the solution.

Implementing the Adorner Provider

The adorner provider is implemented in a type named OpacitySliderAdornerProvider. This adorner enables the user to set the control's Opacity property at design time.

To implement the adorner provider

Add a new class named OpacitySliderAdornerProvider to the CustomControlLibrary.VisualStudio.Design project.

In the Code Editor for OpacitySliderAdornerProvider, replace the automatically generated code with the following code. This code implements a PrimarySelectionAdornerProvider which provides an adorner based on a Slider control.

Imports System
Imports System.Collections.Generic
Imports System.Text
Imports System.Windows.Input
Imports System.Windows
Imports System.Windows.Automation
Imports System.Windows.Controls
Imports System.Windows.Media
Imports System.Windows.Shapes
Imports Microsoft.Windows.Design.Interaction
Imports Microsoft.Windows.Design.Model

Namespace CustomControlLibrary.VisualStudio.Design

    ' The following class implements an adorner provider for the 
    ' adorned control. The adorner is a slider control, which 
    ' changes the Background opacity of the adorned control.
    Class OpacitySliderAdornerProvider
        Inherits PrimarySelectionAdornerProvider
        Private adornedControlModel As ModelItem
        Private batchedChange As ModelEditingScope
        Private opacitySlider As Slider
        Private opacitySliderAdornerPanel As AdornerPanel

        Public Sub New()
            opacitySlider = New Slider()
        End Sub

        ' The following method is called when the adorner is activated.
        ' It creates the adorner control, sets up the adorner panel,
        ' and attaches a ModelItem to the adorned control.
        Protected Overrides Sub Activate(ByVal item As ModelItem)

            ' Save the ModelItem and hook into when it changes.
            ' This enables updating the slider position when 
            ' a new Background value is set.
            adornedControlModel = item
            AddHandler adornedControlModel.PropertyChanged, AddressOf AdornedControlModel_PropertyChanged

            ' Setup the slider's min and max values.
            opacitySlider.Minimum = 0
            opacitySlider.Maximum = 1

            ' Setup the adorner panel.
            ' All adorners are placed in an AdornerPanel
            ' for sizing and layout support.
            Dim myPanel = Me.Panel

            ' The slider extends the full width of the control it adorns.
            AdornerPanel.SetAdornerHorizontalAlignment( _
                opacitySlider, _
                AdornerHorizontalAlignment.Stretch)

            ' Position the adorner above the control it adorns.
            AdornerPanel.SetAdornerVerticalAlignment( _
                opacitySlider, _
                AdornerVerticalAlignment.OutsideTop)

            ' Position the adorner 5 pixels above the control. 
            AdornerPanel.SetAdornerMargin( _
                opacitySlider, _
                New Thickness(0, 0, 0, 5))

            ' Initialize the slider when it is loaded.
            AddHandler opacitySlider.Loaded, AddressOf slider_Loaded

            ' Handle the value changes of the slider control.
            AddHandler opacitySlider.ValueChanged, AddressOf slider_ValueChanged

            AddHandler opacitySlider.PreviewMouseLeftButtonUp, _
                AddressOf slider_MouseLeftButtonUp

            AddHandler opacitySlider.PreviewMouseLeftButtonDown, _
                AddressOf slider_MouseLeftButtonDown

            MyBase.Activate(item)

        End Sub

        ' The Panel utility property demand-creates the 
        ' adorner panel and adds it to the provider's 
        ' Adorners collection.
        Public ReadOnly Property Panel() As AdornerPanel
            Get
                If Me.opacitySliderAdornerPanel Is Nothing Then
                    Me.opacitySliderAdornerPanel = New AdornerPanel()

                    ' Add the adorner to the adorner panel.
                    Me.opacitySliderAdornerPanel.Children.Add(opacitySlider)

                    ' Add the panel to the Adorners collection.
                    Adorners.Add(opacitySliderAdornerPanel)
                End If

                Return Me.opacitySliderAdornerPanel
            End Get
        End Property


        ' The following method deactivates the adorner.
        Protected Overrides Sub Deactivate()
            RemoveHandler adornedControlModel.PropertyChanged, _
                AddressOf AdornedControlModel_PropertyChanged
            MyBase.Deactivate()

        End Sub

        ' The following method handles the PropertyChanged event.
        ' It updates the slider control's value if the adorned control's 
        ' Background property changed,
        Sub AdornedControlModel_PropertyChanged( _
            ByVal sender As Object, _
            ByVal e As System.ComponentModel.PropertyChangedEventArgs)

            If e.PropertyName = "Background" Then
                opacitySlider.Value = GetCurrentOpacity()
            End If

        End Sub

        ' The following method handles the Loaded event.
        ' It assigns the slider control's initial value.
        Sub slider_Loaded(ByVal sender As Object, ByVal e As RoutedEventArgs)

            opacitySlider.Value = GetCurrentOpacity()

        End Sub

        ' The following method handles the MouseLeftButtonDown event.
        ' It calls the BeginEdit method on the ModelItem which represents 
        ' the adorned control.
        Sub slider_MouseLeftButtonDown( _
            ByVal sender As Object, _
            ByVal e As System.Windows.Input.MouseButtonEventArgs)

            batchedChange = adornedControlModel.BeginEdit()

        End Sub

        ' The following method handles the MouseLeftButtonUp event.
        ' It commits any changes made to the ModelItem which represents the
        ' the adorned control.
        Sub slider_MouseLeftButtonUp( _
            ByVal sender As Object, _
            ByVal e As System.Windows.Input.MouseButtonEventArgs)

            If Not (batchedChange Is Nothing) Then
                batchedChange.Complete()
                batchedChange.Dispose()
                batchedChange = Nothing
            End If

        End Sub

        ' The following method handles the slider control's 
        ' ValueChanged event. It sets the value of the 
        ' Background opacity by using the ModelProperty type.
        Sub slider_ValueChanged( _
            ByVal sender As Object, _
            ByVal e As RoutedPropertyChangedEventArgs(Of Double))

            If (True) Then
                Dim newOpacityValue As Double = e.NewValue

                ' During setup, don't make a value local and set the opacity.
                If newOpacityValue = GetCurrentOpacity() Then
                    Return
                End If

                ' Access the adorned control's Background property
                ' by using the ModelProperty type.
                Dim backgroundProperty As ModelProperty = _
                    adornedControlModel.Properties("Background")
                If Not backgroundProperty.IsSet Then
                    ' If the value isn't local, make it local 
                    ' before setting a sub-property value.
                    backgroundProperty.SetValue(backgroundProperty.ComputedValue)
                End If

                ' Set the Opacity property on the Background Brush.
                backgroundProperty.Value.Properties("Opacity").SetValue(newOpacityValue)
            End If
        End Sub

        ' This utility method gets the adorned control's
        ' Background brush by using the ModelItem.
        Function GetCurrentOpacity() As Double

            Dim backgroundBrushComputedValue As Brush = _
            CType(adornedControlModel.Properties("Background").ComputedValue,  _
            Brush)

            Return backgroundBrushComputedValue.Opacity

        End Function
    End Class
End Namespace

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Input;
using System.Windows;
using System.Windows.Automation;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Shapes;
using Microsoft.Windows.Design.Interaction;
using Microsoft.Windows.Design.Model;

namespace CustomControlLibrary.VisualStudio.Design
{
    // The following class implements an adorner provider for the 
    // adorned control. The adorner is a slider control, which 
    // changes the Background opacity of the adorned control.
    class OpacitySliderAdornerProvider : PrimarySelectionAdornerProvider
    {
        private ModelItem adornedControlModel;
        private ModelEditingScope batchedChange;
        private Slider opacitySlider;
        private AdornerPanel opacitySliderAdornerPanel;

        public OpacitySliderAdornerProvider()
        {
            opacitySlider = new Slider();
        }

        // The following method is called when the adorner is activated.
        // It creates the adorner control, sets up the adorner panel,
        // and attaches a ModelItem to the adorned control.
        protected override void Activate(ModelItem item)
        {
            // Save the ModelItem and hook into when it changes.
            // This enables updating the slider position when 
            // a new Background value is set.
            adornedControlModel = item;
            adornedControlModel.PropertyChanged += 
                new System.ComponentModel.PropertyChangedEventHandler(
                    AdornedControlModel_PropertyChanged);

            // Setup the slider's min and max values.
            opacitySlider.Minimum = 0;
            opacitySlider.Maximum = 1;

            // Setup the adorner panel.
            // All adorners are placed in an AdornerPanel
            // for sizing and layout support.
            AdornerPanel myPanel = this.Panel;

            // The slider extends the full width of the control it adorns.
            AdornerPanel.SetAdornerHorizontalAlignment( 
                opacitySlider, 
                AdornerHorizontalAlignment.Stretch);

            // Position the adorner above the control it adorns.
            AdornerPanel.SetAdornerVerticalAlignment(
                opacitySlider, 
                AdornerVerticalAlignment.OutsideTop);

            // Position the adorner 5 pixels above the control. 
            AdornerPanel.SetAdornerMargin(
                opacitySlider, 
                new Thickness(0, 0, 0, 5));

            // Initialize the slider when it is loaded.
            opacitySlider.Loaded += new RoutedEventHandler(slider_Loaded);

            // Handle the value changes of the slider control.
            opacitySlider.ValueChanged += 
                new RoutedPropertyChangedEventHandler<double>(
                    slider_ValueChanged);

            opacitySlider.PreviewMouseLeftButtonUp += 
                new System.Windows.Input.MouseButtonEventHandler(
                    slider_MouseLeftButtonUp);

            opacitySlider.PreviewMouseLeftButtonDown += 
                new System.Windows.Input.MouseButtonEventHandler(
                    slider_MouseLeftButtonDown);

            base.Activate(item);
        }

        // The Panel utility property demand-creates the 
        // adorner panel and adds it to the provider's 
        // Adorners collection.
        public AdornerPanel Panel 
        { 
            get
            {
                if (this.opacitySliderAdornerPanel == null)
                {
                    opacitySliderAdornerPanel = new AdornerPanel();

                    opacitySliderAdornerPanel.Children.Add(opacitySlider);

                    // Add the panel to the Adorners collection.
                    Adorners.Add(opacitySliderAdornerPanel);
                }

                return this.opacitySliderAdornerPanel;
            } 
        }


        // The following method deactivates the adorner.
        protected override void Deactivate()
        {
            adornedControlModel.PropertyChanged -= 
                new System.ComponentModel.PropertyChangedEventHandler(
                    AdornedControlModel_PropertyChanged);
            base.Deactivate();
        }

        // The following method handles the PropertyChanged event.
        // It updates the slider control's value if the adorned control's 
        // Background property changed,
        void AdornedControlModel_PropertyChanged(
            object sender, 
            System.ComponentModel.PropertyChangedEventArgs e)
        {
            if (e.PropertyName == "Background")
            {   
                opacitySlider.Value = GetCurrentOpacity();
            }
        }

        // The following method handles the Loaded event.
        // It assigns the slider control's initial value.
        void slider_Loaded(object sender, RoutedEventArgs e)
        {   
            opacitySlider.Value = GetCurrentOpacity();
        }

        // The following method handles the MouseLeftButtonDown event.
        // It calls the BeginEdit method on the ModelItem which represents 
        // the adorned control.
        void slider_MouseLeftButtonDown(
            object sender, 
            System.Windows.Input.MouseButtonEventArgs e)
        {
            batchedChange = adornedControlModel.BeginEdit();
        }

        // The following method handles the MouseLeftButtonUp event.
        // It commits any changes made to the ModelItem which represents the
        // the adorned control.
        void slider_MouseLeftButtonUp(
            object sender, 
            System.Windows.Input.MouseButtonEventArgs e)
        {
            if (batchedChange != null)
            {
                batchedChange.Complete();
                batchedChange.Dispose();
                batchedChange = null;
            }
        }

        // The following method handles the slider control's 
        // ValueChanged event. It sets the value of the 
        // Background opacity by using the ModelProperty type.
        void slider_ValueChanged(
            object sender, 
            RoutedPropertyChangedEventArgs<double> e)
        {
            double newOpacityValue = e.NewValue;

            // During setup, don't make a value local and set the opacity.
            if (newOpacityValue == GetCurrentOpacity())
            {
                return;
            }

            // Access the adorned control's Background property
            // by using the ModelProperty type.
            ModelProperty backgroundProperty = 
                adornedControlModel.Properties["Background"];
            if (!backgroundProperty.IsSet)
            {
                // If the value isn't local, make it local 
                // before setting a sub-property value.
                backgroundProperty.SetValue(backgroundProperty.ComputedValue);
            }

            // Set the Opacity property on the Background Brush.
            backgroundProperty.Value.Properties["Opacity"].SetValue(newOpacityValue);
        }

        // This utility method gets the adorned control's
        // Background brush by using the ModelItem.
        private double GetCurrentOpacity()
        {
            Brush backgroundBrushComputedValue =
                (Brush)adornedControlModel.Properties["Background"].ComputedValue;

            return backgroundBrushComputedValue.Opacity;
        }
    }
}

Build the solution.

Testing the Design-time Implementation

You can use the ButtonWithDesignTime control as you would use any other WPF control. The WPF Designer handles the creation of all design-time objects.

To test the design-time implementation

Add a new WPF Application project in Visual Basic or Visual C# named DemoApplication to the solution.

MainWindow. XAML é aberto no WPF Designer.
Add a reference to the CustomControlLibrary project.

In XAML view, replace the automatically generated XAML with the following XAML. This XAML adds a reference to the CustomControlLibrary namespace and adds the ButtonWithDesignTime custom control. The button appears in Design view with the text "Design mode active", indicating that it is in design mode. If the button does not appear, you might have to click the Information bar at the top of the designer to reload the view.

<Window x:Class="DemoApplication.MainWindow"
    xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:cc="clr-namespace:CustomControlLibrary;assembly=CustomControlLibrary"
    Title="Window1" Height="300" Width="300">
    <Grid>
        <cc:ButtonWithDesignTime Margin="30,30,30,30" Background="#FFD4D0C8"></cc:ButtonWithDesignTime>
    </Grid>
</Window>

In the Design view, click the ButtonWithDesignTime control to select it.

A Slider control appears above the ButtonWithDesignTime control.
Use the slider control adorner to change the opacity of the button.

In XAML view, the Opacity property is set to the value specified by the Slider control.
Run the DemoApplication project.

At run time, the button has the opacity you set with the adorner.

Próximas etapas

You can add more custom design-time features to your custom controls.

Add a MenuAction to your custom design time. For more information, see Passo a passo: Criando um provedor de menu.
Create an adorner provider for in-place editing. For more information, see Walkthrough: Implementando edição in-loco.
Create a custom color editor, which you can use in the Properties window. For more information, see Walkthrough: Implementando um editor de cores.