通过

如何：获取只读 Freezable 的可写副本

  • 项目

此示例演示如何使用 Clone 方法创建只读 Freezable的可写副本。

在 Freezable 对象标记为只读（“冻结”）后，无法对其进行修改。 但是，可以使用 Clone 方法创建冻结对象的可修改克隆。

例

以下示例创建冻结 SolidColorBrush 对象的可修改克隆。

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;

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

有关 Freezable 对象的详细信息，请参阅 冻结对象概述。

另请参阅