Como: Obter uma Cópia Modificável de um Freezable Somente-Leitura
This example shows how to use the Clone method to create a writable copy of a read-only Freezable.
After a Freezable object is marked as read-only ("frozen"), you cannot modify it. However, you can use the Clone method to create a modifiable clone of the frozen object.
Exemplo
The following example creates a modifiable clone of a frozen SolidColorBrush object.
Dim myButton As New Button()
Dim myBrush As New SolidColorBrush(Colors.Yellow)
' Freezing a Freezable before it provides
' performance improvements if you don't
' intend on modifying it.
If myBrush.CanFreeze Then
' Makes the brush unmodifiable.
myBrush.Freeze()
End If
myButton.Background = myBrush
' If you need to modify a frozen brush,
' the Clone method can be used to
' create a modifiable copy.
Dim myBrushClone As SolidColorBrush = myBrush.Clone()
' Changing myBrushClone does not change
' the color of myButton, because its
' background is still set by myBrush.
myBrushClone.Color = Colors.Red
' Replacing myBrush with myBrushClone
' makes the button change to red.
myButton.Background = myBrushClone
Button myButton = new Button();
SolidColorBrush myBrush = new SolidColorBrush(Colors.Yellow);
// Freezing a Freezable before it provides
// performance improvements if you don't
// intend on modifying it.
if (myBrush.CanFreeze)
{
// Makes the brush unmodifiable.
myBrush.Freeze();
}
myButton.Background = myBrush;
// If you need to modify a frozen brush,
// the Clone method can be used to
// create a modifiable copy.
SolidColorBrush myBrushClone = myBrush.Clone();
// Changing myBrushClone does not change
// the color of myButton, because its
// background is still set by myBrush.
myBrushClone.Color = Colors.Red;
// Replacing myBrush with myBrushClone
// makes the button change to red.
myButton.Background = myBrushClone;
For more information about Freezable objects, see the Visão geral sobre objetos Freezable.
Consulte também
Referência
Conceitos
Visão geral sobre objetos Freezable