How to: Create a Design-time Adorner
The following code example shows how to create an adorner which sets the opacity of the selected custom control at design time.
There is extensive support for this task in Visual Studio. For more information, see Walkthrough: Creating a Design-time Adorner.
Example
The following code example shows how to create a design-time adorner for a Windows Presentation Foundation (WPF) custom control. You can use this adorner in the Windows Presentation Foundation (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.
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";
}
}
}
}
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, ByVal view As DependencyObject)
' 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
AdornerPanel.SetHorizontalStretch(opacitySlider, AdornerStretch.Stretch)
AdornerPanel.SetVerticalStretch(opacitySlider, AdornerStretch.None)
Dim placement As New AdornerPlacementCollection()
' The adorner's width is relative to the content.
' The slider extends the full width of the control it adorns.
placement.SizeRelativeToContentWidth(1.0, 0)
' The adorner's height is the same as the slider's.
placement.SizeRelativeToAdornerDesiredHeight(1.0, 0)
' Position the adorner above the control it adorns.
placement.PositionRelativeToAdornerHeight(-1.0, 0)
' Position the adorner up 5 pixels. This demonstrates
' that these placement calls are additive. These two calls
' are equivalent to the following single call:
' PositionRelativeToAdornerHeight(-1.0, -5).
placement.PositionRelativeToAdornerHeight(0, -5)
AdornerPanel.SetPlacements(opacitySlider, placement)
' 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, view)
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(Control.BackgroundProperty)
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(Brush.OpacityProperty).SetValue(newOpacityValue)
End If
End Sub
' This utility method gets the adorned control's
' Background brush by using the ModelItem.
Function GetCurrentOpacity() As Double
If (True) Then
Dim backgroundBrushComputedValue As Brush = _
CType(adornedControlModel.Properties(Control.BackgroundProperty).ComputedValue, _
Brush)
Return backgroundBrushComputedValue.Opacity
End If
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, DependencyObject view)
{
// 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;
AdornerPanel.SetHorizontalStretch(opacitySlider, AdornerStretch.Stretch);
AdornerPanel.SetVerticalStretch(opacitySlider, AdornerStretch.None);
AdornerPlacementCollection placement = new AdornerPlacementCollection();
// The adorner's width is relative to the content.
// The slider extends the full width of the control it adorns.
placement.SizeRelativeToContentWidth(1.0, 0);
// The adorner's height is the same as the slider's.
placement.SizeRelativeToAdornerDesiredHeight(1.0, 0);
// Position the adorner above the control it adorns.
placement.PositionRelativeToAdornerHeight(-1.0, 0);
// Position the adorner up 5 pixels. This demonstrates
// that these placement calls are additive. These two calls
// are equivalent to the following single call:
// PositionRelativeToAdornerHeight(-1.0, -5).
placement.PositionRelativeToAdornerHeight(0, -5);
AdornerPanel.SetPlacements(opacitySlider, placement);
// 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, view);
}
// 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[Control.BackgroundProperty];
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[Brush.OpacityProperty].SetValue(newOpacityValue);
}
// This utility method gets the adorned control's
// Background brush by using the ModelItem.
private double GetCurrentOpacity()
{
Brush backgroundBrushComputedValue =
(Brush)adornedControlModel.Properties[Control.BackgroundProperty].ComputedValue;
return backgroundBrushComputedValue.Opacity;
}
}
}
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
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 IRegisterMetadata. If found, designers instantiate
' this class and call its Register() method automatically.
Friend Class Metadata
Implements IRegisterMetadata
' Called by the designer to register any design-time metadata.
Public Sub Register() Implements IRegisterMetadata.Register
Dim builder As New AttributeTableBuilder()
' Add the adorner provider to the design-time metadata.
builder.AddCustomAttributes(GetType(ButtonWithDesignTime), _
New FeatureAttribute(GetType(OpacitySliderAdornerProvider)))
MetadataStore.AddAttributeTable(builder.CreateTable())
End Sub
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;
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 IRegisterMetadata. If found, designers instantiate
// this class and call its Register() method automatically.
internal class Metadata : IRegisterMetadata
{
// Called by the designer to register any design-time metadata.
public void Register()
{
AttributeTableBuilder builder = new AttributeTableBuilder();
// Add the adorner provider to the design-time metadata.
builder.AddCustomAttributes(
typeof(ButtonWithDesignTime),
new FeatureAttribute(typeof(OpacitySliderAdornerProvider)));
MetadataStore.AddAttributeTable(builder.CreateTable());
}
}
}
<Window x:Class="DemoApplication.Window1"
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>
<Window x:Class="DemoApplication.Window1"
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>
Compiling the Code
Compile the previous example code in three separate assemblies.
Compiling the Custom Control
Create the ButtonWithDesignTime class.
Add references to the following assemblies.
PresentationCore
PresentationFramework
WindowsBase
Compile the ButtonWithDesignTime class in an assembly named CustomControlLibrary.
vbc /r:PresentationCore.dll /r:PresentationFramework.dll /r:WindowsBase.dll /t:library /out:CustomControlLibrary.dll ButtonWithDesignTime.vbcsc /r:PresentationCore.dll /r:PresentationFramework.dll /r:WindowsBase.dll /t:library /out:CustomControlLibrary.dll ButtonWithDesignTime.cs
Compiling the Custom Adorner
Create the OpacitySliderAdornerProvider and Metadata classes.
Add references to the following assemblies:
PresentationCore
PresentationFramework
WindowsBase
Microsoft.Windows.Design
Microsoft.Windows.Design.Extensibility
Microsoft.Windows.Design.Interaction
Add a reference to the CustomControlLibrary assembly or project.
Compile the OpacitySliderAdornerProvider and Metadata classes in a separate assembly named CustomControlLibrary.VisualStudio.Design. Direct the compiled assembly to the same folder as the CustomControlLibrary assembly.
vbc /r:PresentationCore.dll /r:PresentationFramework.dll /r:WindowsBase.dll /r:Microsoft.Windows.Design.dll /r:Microsoft.Windows.Design.Extensibility.dll /r:Microsoft.Windows.Design.Interaction.dll /r:CustomControlLibrary.dll /t:library /out:CustomControlLibrary.VisualStudio.Design.dll OpacitySliderAdornerProvider.vb Metadata.vbcsc /r:PresentationCore.dll /r:PresentationFramework.dll /r:WindowsBase.dll /r:Microsoft.Windows.Design.dll /r:Microsoft.Windows.Design.Extensibility.dll /r:Microsoft.Windows.Design.Interaction.dll /r:CustomControlLibrary.dll /t:library /out:CustomControlLibrary.VisualStudio.Design.dll OpacitySliderAdornerProvider.cs Metadata.cs
Compiling the Test Application
In Visual Studio, create a new WPF Application project.
Add a reference to the CustomControlLibrary assembly or project.
Replace the existing XAML in Window1.xaml with the XAML listed earlier.
In Design view, a Slider control appears above the ButtonWithDesignTime control.
See Also
Tasks
Walkthrough: Creating a Design-time Adorner
Reference
PrimarySelectionAdornerProvider