Visual.TransformToDescendant(Visual) 方法

定義

傳回轉換,這個轉換可用來將 Visual 的座標轉換為指定的視覺物件子系。Returns a transform that can be used to transform coordinates from the Visual to the specified visual object descendant.

public:
 System::Windows::Media::GeneralTransform ^ TransformToDescendant(System::Windows::Media::Visual ^ descendant);
public System.Windows.Media.GeneralTransform TransformToDescendant (System.Windows.Media.Visual descendant);
member this.TransformToDescendant : System.Windows.Media.Visual -> System.Windows.Media.GeneralTransform
Public Function TransformToDescendant (descendant As Visual) As GeneralTransform

參數

descendant
Visual

座標會轉換為 VisualThe Visual to which the coordinates are transformed.

傳回

型別 GeneralTransform 的值。A value of type GeneralTransform.

例外狀況

descendantnulldescendant is null.

視覺不是 descendant 視覺物件的祖系。The visual is not an ancestor of the descendant visual.

這些視覺物件都不會產生關聯。The visual objects are not related.

範例

下列標記範例顯示包含在 StackPanel 物件內的 TextBlockThe following markup example shows a TextBlock that is contained within a StackPanel object.

<StackPanel Name="myStackPanel" Margin="8">
  <TextBlock Name="myTextBlock" Margin="4" Text="Hello, world" />
</StackPanel>

下列程式碼範例示範如何使用 TransformToDescendant 方法來抓取相對於其子 TextBlockStackPanel 位移。The following code example shows how to use the TransformToDescendant method to retrieve the offset of the StackPanel relative to its child TextBlock. 位移值會包含在傳回的 GeneralTransform 值內。The offset values are contained within the returned GeneralTransform value.

// Return the general transform for the specified visual object.
GeneralTransform generalTransform1 = myStackPanel.TransformToDescendant(myTextBlock);

// Retrieve the point value relative to the child.
Point currentPoint = generalTransform1.Transform(new Point(0, 0));
' Return the general transform for the specified visual object.
Dim generalTransform1 As GeneralTransform = myStackPanel.TransformToDescendant(myTextBlock)

' Retrieve the point value relative to the child.
Dim currentPoint As Point = generalTransform1.Transform(New Point(0, 0))

位移會考慮所有物件的 Margin 值。The offset takes into account the Margin values for all objects. 在此情況下,X 為-4,Y 為-4。In this case, X is -4, and Y is -4. 位移值是負值,因為父物件相對於其子物件有負面的位移。The offset values are negative values because the parent object is negatively offset relative to its child object.

適用於