How to: Create a Custom Feature Connector

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The following code examples show how to implement a custom feature connector. For more information, see Walkthrough: Creating a Design-time Adorner.

Example

The following code example shows how to derive from the FeatureConnector<TFeatureProviderType> class to connect a custom feature provider named DiagnosticsMenuProvider with a custom service named IDiagnosticsService.

Imports System
Imports System.Windows

' The DemoButton control provides a button that 
' has custom design-time behavior.  
Public Class DemoButton
    Inherits System.Windows.Controls.Button
End Class

using System;
using System.Windows;

namespace DemoControlLibrary
{
    // The DemoButton control provides a button that 
    // has custom design-time behavior.  
    public class DemoButton : System.Windows.Controls.Button 
    {

    }
}

Imports System
Imports Microsoft.Windows.Design.Features
Imports Microsoft.Windows.Design.Interaction

' The DiagnosticsMenuProvider class adds a context menu item 
' that displays a dialog box listing the currently running and  
' pending feature connectors. 
<FeatureConnector(GetType(DiagnosticsFeatureConnector))>  _
Public Class DiagnosticsMenuProvider
    Inherits PrimarySelectionContextMenuProvider

    Public Sub New() 
        Dim action As New MenuAction("Feature Diagnostics...")

        AddHandler action.Execute, AddressOf action_Execute 

        Items.Add(action)    
    End Sub 

    Sub action_Execute(ByVal sender As Object, ByVal e As MenuActionEventArgs) 
        Dim service As IDiagnosticsService = e.Context.Services.GetRequiredService(Of IDiagnosticsService)()

        service.ShowWindow()

    End Sub 

End Class 

' The IDiagnosticsService specifies a simple interface for showing 
' a FeatureManagerDiagnostics window. 
Interface IDiagnosticsService
    Sub ShowWindow() 
End Interface 

' The DiagnosticsFeatureConnector publishes the IDiagnosticsService.  
Class DiagnosticsFeatureConnector
    Inherits FeatureConnector(Of DiagnosticsMenuProvider)
    Implements IDiagnosticsService

    Dim fmdWindow As FeatureManagerDiagnostics

    Public Sub New(ByVal manager As FeatureManager) 
        MyBase.New(manager)

        Context.Services.Publish(Of IDiagnosticsService)(Me)

    End Sub 

    ' The showWindow method creates a FeatureManagerDiagnostics 
    ' window and shows it. 
    Public Sub ShowWindow() Implements IDiagnosticsService.ShowWindow

        If fmdWindow IsNot Nothing Then 

            ' Show the FeatureManagerDiagnostics window.
            fmdWindow.Show()

            ' Activate the 
            fmdWindow.Activate()

        Else

            fmdWindow = New FeatureManagerDiagnostics()
            fmdWindow.Initialize(Manager)
            AddHandler fmdWindow.Closed, AddressOf fmdWindow_Closed
            fmdWindow.Show()

        End If 

    End Sub 

    Sub fmdWindow_Closed(ByVal sender As Object, ByVal e As EventArgs)

        fmdWindow = Nothing 

    End Sub 

End Class

using System;
using Microsoft.Windows.Design.Features;
using Microsoft.Windows.Design.Interaction;

namespace DemoControlLibrary.VisualStudio.Design
{
    // The DiagnosticsMenuProvider class adds a context menu item 
    // that displays a dialog box listing the currently running and  
    // pending feature connectors. 
    [FeatureConnector(typeof(DiagnosticsFeatureConnector))]
    public class DiagnosticsMenuProvider : PrimarySelectionContextMenuProvider 
    {
        public DiagnosticsMenuProvider() 
        {
            MenuAction action = new MenuAction("Feature Diagnostics...");

            action.Execute += new EventHandler<MenuActionEventArgs>(action_Execute); 

            Items.Add(action);
        }

        void action_Execute(object sender, MenuActionEventArgs e)
        {
            IDiagnosticsService service = 
                e.Context.Services.GetRequiredService<IDiagnosticsService>();

            service.ShowWindow();
        }
    }

    // The IDiagnosticsService specifies a simple interface for showing 
    // a FeatureManagerDiagnostics window. 
    interface IDiagnosticsService 
    {
        void ShowWindow();
    }

    // The DiagnosticsFeatureConnector publishes the IDiagnosticsService.  
    class DiagnosticsFeatureConnector : FeatureConnector<DiagnosticsMenuProvider>,
        IDiagnosticsService 
    {
        FeatureManagerDiagnostics fmdWindow;

        public DiagnosticsFeatureConnector(FeatureManager manager)
            : base(manager) 
        {
            Context.Services.Publish<IDiagnosticsService>(this);
        }

        #region IDiagnosticsService Members

        // The showWindow method creates a FeatureManagerDiagnostics 
        // window and shows it. 
        public void ShowWindow() 
        {
            if (fmdWindow != null) 
            {
                fmdWindow.Show();
                fmdWindow.Activate();
            }
            else 
            {
                fmdWindow = new FeatureManagerDiagnostics();
                fmdWindow.Initialize(Manager);
                fmdWindow.Closed += new EventHandler(fmdWindow_Closed); 
                fmdWindow.Show();
            }
        }

        void fmdWindow_Closed(object sender, EventArgs e)
        {
            fmdWindow = null; 
        }

        #endregion
    }
}

Imports System
Imports System.Collections.Generic
Imports System.Text
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Data
Imports System.Windows.Documents
Imports System.Windows.Input
Imports System.Windows.Media
Imports System.Windows.Media.Imaging
Imports System.Windows.Shapes

Imports Microsoft.Windows.Design.Features

' The FeatureManagerDiagnostics class implements a window 
' that displays the running and pending feature connectors. 
Partial Public Class FeatureManagerDiagnostics
    Inherits Window

    Private featManager As FeatureManager

    Public Sub New()
        InitializeComponent()

    End Sub 

    Public Sub Initialize(ByVal manager As FeatureManager)
        featManager = manager
        Bind()
    End Sub 

    Private Sub OnRefreshClick(ByVal sender As Object, ByVal e As RoutedEventArgs)
        Bind()
    End Sub 

    ' Binds the activatedFeatures and pendingFeatures controls 
    ' the FeatureManager's RunningConnectors and PendingConnectors\ 
    ' properties. 
    Private Sub Bind()
        activatedFeatures.Items.Clear()
        pendingFeatures.Items.Clear()

        Dim info As FeatureConnectorInformation
        For Each info In featManager.RunningConnectors
            activatedFeatures.Items.Add(info)
        Next info

        For Each info In featManager.PendingConnectors
            pendingFeatures.Items.Add(info)
        Next info

    End Sub 

End Class

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;

using Microsoft.Windows.Design.Features;

namespace DemoControlLibrary.VisualStudio.Design
{
    // The FeatureManagerDiagnostics class implements a window 
    // that displays the running and pending feature connectors. 
    public partial class FeatureManagerDiagnostics : Window 
    {
        private FeatureManager featManager;

        public FeatureManagerDiagnostics() 
        {
            InitializeComponent();
        }

        public void Initialize(FeatureManager manager) 
        {
            featManager = manager;
            Bind();
        }

        private void OnRefreshClick(object sender, RoutedEventArgs e) 
        {
            Bind();
        }

        // Binds the activatedFeatures and pendingFeatures controls 
        // the FeatureManager's RunningConnectors and PendingConnectors\ 
        // properties. 
        private void Bind() 
        {
            activatedFeatures.Items.Clear();
            pendingFeatures.Items.Clear();

            foreach (FeatureConnectorInformation info in 
                featManager.RunningConnectors) 
            {
                activatedFeatures.Items.Add(info);
            }

            foreach (FeatureConnectorInformation info in 
                featManager.PendingConnectors) 
            {
                pendingFeatures.Items.Add(info);
            }
        }
    }
}

<Window 
  xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:l="clr-namespace:DemoControlLibrary.VisualStudio.Design"
  x:Class="FeatureManagerDiagnostics"
  Title="Feature Diagnostics" WindowStartupLocation="CenterOwner" SizeToContent="Manual" Height="316" Width="448" >

  <Window.Resources>
    <Style x:Key="HeaderStyle" TargetType="HeaderedItemsControl">

      <Setter Property="Template">
        <Setter.Value>
          <ControlTemplate TargetType="HeaderedItemsControl">
            <StackPanel>
              <Border Padding="5" Background="#FFDDDDDD">
                <CheckBox IsChecked="True" FontWeight="Bold" Name="Expander" Content="{TemplateBinding Header}"/>
              </Border>
              <Border Padding="5" Name="ItemsHost">
                <ItemsPresenter/>
              </Border>
            </StackPanel>

            <ControlTemplate.Triggers>
              <Trigger SourceName="Expander" Property="ToggleButton.IsChecked" Value="true">
                <Setter TargetName="ItemsHost" Property="Visibility" Value="Visible" />
              </Trigger>
              <Trigger SourceName="Expander" Property="ToggleButton.IsChecked" Value="false">
                <Setter TargetName="ItemsHost" Property="Visibility" Value="Collapsed" />
              </Trigger>
            </ControlTemplate.Triggers>
          </ControlTemplate>
        </Setter.Value>
      </Setter>
    </Style>

    <DataTemplate x:Key="FeatureInfo" DataType="l:FeatureConnectorInformation">
      <StackPanel>
        <Border BorderBrush="{x:Static SystemColors.ActiveCaptionBrush}" BorderThickness="0,0,0,1">
          <TextBlock FontWeight="Bold" Text="{Binding Path=FeatureConnectorType}" />
        </Border>
        <Border Padding="15,0,0,5" TextElement.FontSize = "10">
          <StackPanel>
            <TextBlock FontWeight="Bold" Text="Required Services" />
            <Border Padding="10,0,0,5">
              <ItemsControl ItemsSource="{Binding Path=RequiredServices}" />
            </Border>
            <TextBlock FontWeight="Bold" Text="Required Context Items" />
            <Border Padding="10,0,0,5">
              <ItemsControl ItemsSource="{Binding Path=RequiredItems}" />
            </Border>
          </StackPanel>
        </Border>
      </StackPanel>
    </DataTemplate>

    <DataTemplate x:Key="PendingFeatureInfo" DataType="l:FeatureConnectorInformation">
      <StackPanel>
        <Border BorderBrush="{x:Static SystemColors.ActiveCaptionBrush}" BorderThickness="0,0,0,1">
          <TextBlock FontWeight="Bold" Text="{Binding Path=FeatureConnectorType}" />
        </Border>
        <Border Padding="15,0,0,5" TextElement.FontSize = "10">
          <StackPanel>
            <TextBlock FontWeight="Bold" Text="Missing Services" />
            <Border Padding="10,0,0,5">
              <ItemsControl ItemsSource="{Binding Path=PendingServices}" />
            </Border>
            <TextBlock FontWeight="Bold" Text="Missing Context Items" />
            <Border Padding="10,0,0,5">
              <ItemsControl ItemsSource="{Binding Path=PendingItems}" />
            </Border>
          </StackPanel>
        </Border>
      </StackPanel>
    </DataTemplate>
  </Window.Resources> 

  <Grid>
    <ScrollViewer Margin="0,0,0,36" VerticalScrollBarVisibility="Auto">
      <StackPanel>
        <HeaderedItemsControl Name="pendingFeatures" Style="{StaticResource HeaderStyle}" Header="Pending Features" ItemTemplate="{StaticResource PendingFeatureInfo}" />
        <HeaderedItemsControl Name="activatedFeatures" Style="{StaticResource HeaderStyle}" Header="Activated Features" ItemTemplate="{StaticResource FeatureInfo}" />
      </StackPanel>
    </ScrollViewer>
    <Button Height="23" Margin="0,0,8,7" Click="OnRefreshClick" VerticalAlignment="Bottom" HorizontalAlignment="Right" Width="75">Refresh</Button>
  </Grid>

</Window>

<Window 
  xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml"
  xmlns:l="clr-namespace:DemoControlLibrary.VisualStudio.Design" 
  x:Class="DemoControlLibrary.VisualStudio.Design.FeatureManagerDiagnostics"
  Title="Feature Diagnostics" WindowStartupLocation="CenterOwner" SizeToContent="Manual" Height="316" Width="448" >

  <Window.Resources>
    <Style x:Key="HeaderStyle" TargetType="HeaderedItemsControl">

      <Setter Property="Template">
        <Setter.Value>
          <ControlTemplate TargetType="HeaderedItemsControl">
            <StackPanel>
              <Border Padding="5" Background="#FFDDDDDD">
                <CheckBox IsChecked="True" FontWeight="Bold" Name="Expander" Content="{TemplateBinding Header}"/>
              </Border>
              <Border Padding="5" Name="ItemsHost">
                <ItemsPresenter/>
              </Border>
            </StackPanel>

            <ControlTemplate.Triggers>
              <Trigger SourceName="Expander" Property="ToggleButton.IsChecked" Value="true">
                <Setter TargetName="ItemsHost" Property="Visibility" Value="Visible" />
              </Trigger>
              <Trigger SourceName="Expander" Property="ToggleButton.IsChecked" Value="false">
                <Setter TargetName="ItemsHost" Property="Visibility" Value="Collapsed" />
              </Trigger>
            </ControlTemplate.Triggers>
          </ControlTemplate>
        </Setter.Value>
      </Setter>
    </Style>

    <DataTemplate x:Key="FeatureInfo" DataType="l:FeatureConnectorInformation">
      <StackPanel>
        <Border BorderBrush="{x:Static SystemColors.ActiveCaptionBrush}" BorderThickness="0,0,0,1">
          <TextBlock FontWeight="Bold" Text="{Binding Path=FeatureConnectorType}" />
        </Border>
        <Border Padding="15,0,0,5" TextElement.FontSize = "10">
          <StackPanel>
            <TextBlock FontWeight="Bold" Text="Required Services" />
            <Border Padding="10,0,0,5">
              <ItemsControl ItemsSource="{Binding Path=RequiredServices}" />
            </Border>
            <TextBlock FontWeight="Bold" Text="Required Context Items" />
            <Border Padding="10,0,0,5">
              <ItemsControl ItemsSource="{Binding Path=RequiredItems}" />
            </Border>
          </StackPanel>
        </Border>
      </StackPanel>
    </DataTemplate>

    <DataTemplate x:Key="PendingFeatureInfo" DataType="l:FeatureConnectorInformation">
      <StackPanel>
        <Border BorderBrush="{x:Static SystemColors.ActiveCaptionBrush}" BorderThickness="0,0,0,1">
          <TextBlock FontWeight="Bold" Text="{Binding Path=FeatureConnectorType}" />
        </Border>
        <Border Padding="15,0,0,5" TextElement.FontSize = "10">
          <StackPanel>
            <TextBlock FontWeight="Bold" Text="Missing Services" />
            <Border Padding="10,0,0,5">
              <ItemsControl ItemsSource="{Binding Path=PendingServices}" />
            </Border>
            <TextBlock FontWeight="Bold" Text="Missing Context Items" />
            <Border Padding="10,0,0,5">
              <ItemsControl ItemsSource="{Binding Path=PendingItems}" />
            </Border>
          </StackPanel>
        </Border>
      </StackPanel>
    </DataTemplate>
  </Window.Resources>

  <Grid>
    <ScrollViewer Margin="0,0,0,36" VerticalScrollBarVisibility="Auto">
      <StackPanel>
        <HeaderedItemsControl Name="pendingFeatures" Style="{StaticResource HeaderStyle}" Header="Pending Features" ItemTemplate="{StaticResource PendingFeatureInfo}" />
        <HeaderedItemsControl Name="activatedFeatures" Style="{StaticResource HeaderStyle}" Header="Activated Features" ItemTemplate="{StaticResource FeatureInfo}" />
      </StackPanel>
    </ScrollViewer>
    <Button Height="23" Margin="0,0,8,7" Click="OnRefreshClick" VerticalAlignment="Bottom" HorizontalAlignment="Right" Width="75">Refresh</Button>
  </Grid>
</Window>

Imports System
Imports DemoControlLibrary

Imports Microsoft.Windows.Design.Metadata
Imports Microsoft.Windows.Design.Features

' Container for any general design-time metadata to initialize. 
' Designers look for a type in the design-time assembly that  
' implements IRegisterMetadata. If found, designers instantiate  
' this class and call its Register() method automatically. 
Friend Class Metadata
    Implements IRegisterMetadata

    Public Sub Register() Implements IRegisterMetadata.Register
        Dim builder As New AttributeTableBuilder()
        InitializeAttributes(builder)
        MetadataStore.AddAttributeTable(builder.CreateTable())
    End Sub 

    Private Sub InitializeAttributes(ByVal builder As AttributeTableBuilder) 
        builder.AddCallback(GetType(DemoButton), AddressOf AddButtonAttributes)

    End Sub 

    Private Sub AddButtonAttributes(ByVal builder As AttributeCallbackBuilder) 
        builder.AddCustomAttributes(New FeatureAttribute(GetType(DiagnosticsMenuProvider)))
    End Sub 
End Class 
' <//snippet101>

using System;
using DemoControlLibrary;

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

namespace DemoControlLibrary.VisualStudio.Design
{
    // Container for any general design-time metadata to initialize. 
    // Designers look for a type in the design-time assembly that  
    // implements IRegisterMetadata. If found, designers instantiate  
    // this class and call its Register() method automatically. 
    internal class Metadata : IRegisterMetadata 
    {
        public void Register() 
        {
            AttributeTableBuilder builder = new AttributeTableBuilder();
            InitializeAttributes(builder);
            MetadataStore.AddAttributeTable(builder.CreateTable());
        }

        private void InitializeAttributes(AttributeTableBuilder builder) 
        {
            builder.AddCallback(typeof(DemoButton), AddButtonAttributes);
        }

        private void AddButtonAttributes(AttributeCallbackBuilder builder)
        {
            builder.AddCustomAttributes(
                new FeatureAttribute(typeof(DiagnosticsMenuProvider))
            );
        }
    }
    // <//snippet101>
}

    <Window x:Class="Window1"
    xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:c="clr-namespace:DemoControlLibrary;assembly=DemoControlLibrary"
    Title="Window1" Height="300" Width="300">
    <Grid>
        <c:DemoButton />
    </Grid>
</Window>

<Window x:Class="DemoApplication.Window1"
    xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:c="clr-namespace:DemoControlLibrary;assembly=DemoControlLibrary" 
    Title="Window1" Height="300" Width="300">
    <Grid>
        <c:DemoButton />
    </Grid>
</Window>

The DemoButton class derives from Button and provides a class to which design-time metadata is attached.

The DiagnosticsMenuProvider class adds a context menu item that displays the FeatureManagerDiagnostics window.

The FeatureManagerDiagnostics class implements a window that displays the running and pending feature connectors.

The Metadata class attaches the DiagnosticsMenuProvider to the DemoButton by using the MetadataStore class.

Compiling the Code

Compile the previous example code in three separate assemblies.

Compiling the Custom Control

  1. In Visual Studio, create a new WPF Custom Control Library project named named DemoControlLibrary.

  2. Change all occurrences of "CustomControl1" with "DemoButton".

  3. Replace the existing code in the DemoButton class with the code listed earlier.

  4. Build the solution.

Compiling the Custom Feature Connector

  1. Add a new WPF Custom Control Library project named DemoControlLibrary.VisualStudio.Design to the solution.

  2. Set the project's output path to "..\DemoControlLibrary\bin\Debug\".

  3. Delete Generic.xaml from the project.

  4. Add references to the following assemblies.

    • Microsoft.Windows.Design

    • Microsoft.Windows.Design.Extensibility

    • Microsoft.Windows.Design.Interaction

  5. Add a reference to the DemoControlLibrary project.

  6. Change all occurrences of "CustomControl1" with "DiagnosticsMenuProvider".

  7. Replace the existing code in the DiagnosticsMenuProvider class with the code listed earlier.

  8. Add a Window (WPF) item named FeatureManagerDiagnostics to the project.

  9. Replace the existing code in the FeatureManagerDiagnostics class with the code listed earlier.

  10. Replace the existing XAML in FeatureManagerDiagnostics.xaml with the XAML listed earlier.

  11. Add a class named Metadata to the project.

  12. Replace the existing code in the Metadata class with the code listed earlier.

  13. Build the solution.

Compiling the Test Application

  1. Add a new WPF Application project named DemoApplication to the solution.

  2. Add a reference to the DemoControlLibrary project.

  3. Replace the existing XAML in Window1.xaml with the XAML listed earlier.

  4. In Design view, right-click the button and select Feature Diagnostics.

    The Feature Diagnostics window appears, showing pending and activated feature connectors.

See Also

Tasks

Walkthrough: Creating a Design-time Adorner

Concepts

Feature Providers and Feature Connectors

Reference

FeatureManager

FeatureProvider

FeatureConnector<TFeatureProviderType>

FeatureConnectorAttribute

MetadataStore

Other Resources

WPF Designer Extensibility