演练：创建设计时装饰器

项目
05/28/2012

[本文档仅供预览，在以后的发行版中可能会发生更改。包含的空白主题用作占位符。]

本演练演示如何创建 windows presentation foundation (WPF) 自定义控件的设计时装饰器。在适用于 Visual Studio 的 WPF 设计器可以使用此装饰器设置 Opacity 属性的值在自定义按钮控件上。对于本演练，控件是一个简单的按钮，装饰器是一个用来更改按钮不透明度的滑块。有关完整的代码清单，请参见从站点的 opacity slider Adorner WPF 设计器扩展性示例 "。

在本演练中，您将执行下列任务:

创建一个 WPF 自定义控件库项目。
创建设计时元数据的一个单独的程序集。
实现装饰器提供程序。
在设计时测试控件。

完成后，您将知道如何为自定义控件创建装饰器提供程序。

备注

您看到的对话框和菜单命令可能会与 " 帮助 " 中的描述不同具体取决于您现用的设置或版本。若要更改设置，请选择在工具菜单的 导入和导出设置 。有关更多信息，请参见 Visual Studio 设置。

系统必备

您需要以下组件来完成本演练:

Visual Studio 2012 RC.

创建自定义控件

第一步是为自定义控件创建项目。该控件是带有少量设计时代码的一个简单的按钮，使用 GetIsInDesignMode 方法实现设计时行为。

创建自定义控件

创建新 WPF 自定义控件库名为 CustomControlLibrary的项目在 Visual Basic 或 Visual C#。

CustomControl1 的代码在代码编辑器中打开。
在 解决方案资源管理器，将代码文件的名称更改为 ButtonWithDesignTime.cs 或 ButtonWithDesignTime.vb。如果此项目请求的出现消息框是要执行重命名所有引用，单击是。
打开 ButtonWithDesignTime.cs 或 ButtonWithDesignTime.vb 在代码编辑器中。

用下面的代码替换自动生成的代码。，当按钮出现在设计器中时， ButtonWithDesignTime 自定义控件从 Button 继承并显示文本 “已激活设计模式”。 GetIsInDesignMode 检查和下面的设计时代码可选和仅演示。

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";
            }
        }
    }
}

将项目的输出路径设置为 “bin \”。
生成解决方案。

创建设计时元数据程序集

设计时代码在特定元数据程序集中部署。对于本演练，自定义装饰器 Visual Studio 在名为 CustomControlLibrary.VisualStudio.Design 的程序集仅支持和部署。有关更多信息，请参见提供设计时元数据。

创建设计时元数据程序集

在 Visual Basic 中添加个新的类库名为 CustomControlLibrary.VisualStudio.Design 的项目或 Visual c# 为解决方案。
将项目的输出路径设置为 “ \ CustomControlLibrary \ bin \”。这在同一文件夹使控件的程序集和元数据程序集，使设计器的元数据发现。
添加对下列 WPF 程序集。
- PresentationCore
- PresentationFramework
- System.Xaml
- WindowsBase
添加对以下 WPF Designer 程序集。
- Microsoft.Windows.Design.Extensibility
- Microsoft.Windows.Design.Interaction
添加对 CustomControlLibrary 项目。
在 解决方案资源管理器，将 Class1 代码文件的名称改为 Metadata.cs 或 Metadata.vb。

用下面的代码替换自动生成的代码。将自定义设计时实现附加到 ButtonWithDesignTime 类的此代码创建 AttributeTable 。

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();
            }
        }
    }
}

保存解决方案。

实现装饰器提供程序

装饰器提供程序是在名为 OpacitySliderAdornerProvider的类型中实现的。此装饰器允许用户设置控件的 Opacity 属性在设计时。

实现装饰器提供程序

将名为 OpacitySliderAdornerProvider 的新类添加到 CustomControlLibrary.VisualStudio.Design 项目。

在 OpacitySliderAdornerProvider的代码编辑器中，用以下代码替换自动生成的代码。提供基于 Slider 控件的装饰器的此代码实现 PrimarySelectionAdornerProvider 。

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;
        }
    }
}

生成解决方案。

测试设计时实现

代码，就象使用任何其他 WPF 控件，可以使用 ButtonWithDesignTime 控件。 WPF Designer 处理所有设计时对象的创建。

测试设计时实现

添加在 Visual Basic 中的新 WPF 名为 DemoApplication 的应用程序项目或 Visual c# 为解决方案。

在 MainWindow.xaml WPF Designer打开。
添加对 CustomControlLibrary 项目。

在 XAML 视图中，用以下 XAML 替换自动生成的 XAML。此 XAML 将添加对 CustomControlLibrary 命名空间并添加 ButtonWithDesignTime 自定义控件。该按钮出现在且带有文本 “已激活设计模式”设计 " 视图中，表明该按钮处于设计模式下。如果该按钮未出现，可能需要单击设计器顶部的信息栏以重新加载视图。

<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>

在设计视图中，单击 ButtonWithDesignTime 选择控件。

Slider 控件在 ButtonWithDesignTime 控件上方。
使用滑块控件装饰器更改按钮的不透明度。

在 XAML 视图中， Opacity 属性设置为 Slider 控件指定的值。
运行 DemoApplication 项目。

在运行时，该按钮的不透明度您用装饰器设置。

后续步骤

可以添加更多的自定义设计时功能。您的自定义控件。

添加 MenuAction 到自定义设计时。有关更多信息，请参见演练：创建菜单提供程序。
创建就地编辑的装饰器提供程序。有关更多信息，请参见演练：实现就地编辑。
创建自定义颜色编辑器，可在 " 属性 " 窗口中使用。有关更多信息，请参见演练：实现颜色编辑器。

请参见

演练：创建设计时装饰器

系统必备

创建自定义控件

创建自定义控件

创建设计时元数据程序集

创建设计时元数据程序集

实现装饰器提供程序

实现装饰器提供程序

测试设计时实现

测试设计时实现

后续步骤

请参见

参考

概念

其他资源

其他资源