Visual.TransformToAncestor Method (Visual)
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Returns a transform that can be used to transform coordinates from the Visual to the specified Visual ancestor of the visual object.
Assembly: PresentationCore (in PresentationCore.dll)
Parameters
- ancestor
-
Type:
System.Windows.Media.Visual
The Visual to which the coordinates are transformed.
| Exception | Condition |
|---|---|
| ArgumentNullException | ancestor is null. |
| ArgumentException | ancestor is not an ancestor of the visual. |
| InvalidOperationException | The visual objects are not related. |
Alternatively, you can use the VisualTreeHelper.GetOffset method to retrieve the offset of a visual object relative to its parent. The offset values are contained within the returned Vector value.
The following markup example shows a TextBlock that is nested within two StackPanel objects.
<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" > <StackPanel Margin="16"> <StackPanel Margin="8"> <TextBlock Name="myTextBlock" Margin="4" Text="Hello, world" /> </StackPanel> </StackPanel> </Window>
The following code example shows how to use the TransformToAncestor method to retrieve the offset of the TextBlock relative to the containing Window. The offset values are contained in the returned GeneralTransform.
// Return the general transform for the specified visual object. GeneralTransform generalTransform1 = myTextBlock.TransformToAncestor(this); // Retrieve the point value relative to the parent. Point currentPoint = generalTransform1.Transform(new Point(0, 0));
The offset takes into account the Margin values for all objects within the containing Window. In this case, X is 28, and Y is 28.
Available since 3.0