AdornerProvider Class
A feature provider that you can add to a class to automatically add adorners to the designer surface.
Namespace: Microsoft.Windows.Design.Interaction
Assembly: Microsoft.Windows.Design.Extensibility (in Microsoft.Windows.Design.Extensibility.dll)
Syntax
'Declaration
Public MustInherit Class AdornerProvider _
Inherits FeatureProvider
'Usage
Dim instance As AdornerProvider
public abstract class AdornerProvider : FeatureProvider
public ref class AdornerProvider abstract : public FeatureProvider
public abstract class AdornerProvider extends FeatureProvider
Remarks
Adorners are added according to an AdornerProvider's policy. You can add a policy to an AdornerProvider by adding a UsesItemPolicyAttribute to the class definition.
To add adorners that appear during selection, derive from PrimarySelectionAdornerProvider as it already has the correct policy attribute applied.
Examples
The following code example shows how to derive a custom type from the PrimarySelectionAdornerProvider class. The custom type creates an AdornerPanel to host a Slider control, which is used at design-time to set the Background property of the adorned control. For more information, see Walkthrough: Creating a Design-time Adorner.
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;
}
}
}
Inheritance Hierarchy
System.Object
Microsoft.Windows.Design.Features.FeatureProvider
Microsoft.Windows.Design.Interaction.AdornerProvider
Microsoft.Windows.Design.Interaction.PrimarySelectionAdornerProvider
Thread Safety
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
See Also
Reference
Microsoft.Windows.Design.Interaction Namespace