Captures property changes that are made by the user in the designer and provides new values at design time.
(in Microsoft.Windows.Design.Extensibility.dll)
Visual Basic (Declaration)
Public Class DesignModeValueProvider _
Inherits FeatureProvider
Dim instance As DesignModeValueProvider
public class DesignModeValueProvider : FeatureProvider
public ref class DesignModeValueProvider : public FeatureProvider
public class DesignModeValueProvider extends FeatureProvider
Normally, when a user changes a property value of an object in the designer, that value is set on the object in the designer. By using the DesignModeValueProvider class, you can insert your own logic into this process. For example, you want the user to be able to set the visible property of a control to false, but the control should still be visible at design time.
To accomplish this, you create a DesignModeValueProvider and attach it to your custom control. The DesignModeValueProvider captures property changes that the user makes, you insert your own logic in the TranslatePropertyValue method, and the DesignModeValueProvider passes the new values to the designer.
.gif) Important Note: |
|---|
When you use this technique, the behavior of a property in the designer does not match the value of the property in XAML view. XAML view displays the value that the user entered at design time. The value in XAML view represents the behavior that the property will exhibit at run time. |
The following example creates a custom DesignModeValueProvider that will be attached to a custom button control. In the TranslatePropertyValue method, you change the Content property of the Button so that it appears uppercase in the designer. You also change the Background property of the Button so that it appears with the default system color in the designer. These changes affect the designer only. At run time, the Content and the Background properties appear with the values set by the user.
For more information, see Walkthrough: Changing the Behavior of a Property at Design Time.
Imports System
Imports System.Windows 'SystemColors
Imports System.Windows.Media 'SolidColorBrush
Imports System.Windows.Controls 'Button
Imports Microsoft.Windows.Design.Model 'DesignModeValueProvider
Namespace CustomButton
Public Class CustomButtonDesignModeValueProvider
Inherits DesignModeValueProvider
Public Sub New()
Properties.Add(Button.ContentProperty)
Properties.Add(Button.BackgroundProperty)
End Sub
Public Overrides Function TranslatePropertyValue(ByVal identifier As PropertyIdentifier, ByVal value As Object) As Object
If identifier.DependencyProperty Is Button.ContentProperty Then
Return value.ToString().ToUpper()
End If
If identifier.DependencyProperty Is Button.BackgroundProperty Then
Return New SolidColorBrush(SystemColors.ControlColor)
End If
Return MyBase.TranslatePropertyValue(identifier, value)
End Function
End Class
End Namespace
using System;
using System.Windows; //SystemColors
using System.Windows.Media; //SolidColorBrush
using System.Windows.Controls; //Button
using Microsoft.Windows.Design.Model; //DesignModeValueProvider
namespace CustomButton
{
class CustomButtonDesignModeValueProvider : DesignModeValueProvider
{
public CustomButtonDesignModeValueProvider()
{
Properties.Add(Button.ContentProperty);
Properties.Add(Button.BackgroundProperty);
}
public override object TranslatePropertyValue(PropertyIdentifier identifier, object value)
{
if (identifier.DependencyProperty == Button.ContentProperty)
{
return ((string)value).ToUpper();
}
if (identifier.DependencyProperty == Button.BackgroundProperty)
{
return new SolidColorBrush(SystemColors.ControlColor);
}
return base.TranslatePropertyValue(identifier, value);
}
}
}
System..::.Object
Microsoft.Windows.Design.Features..::.FeatureProvider
Microsoft.Windows.Design.Model..::.DesignModeValueProvider
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Reference
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