VisualTreeHelper.GetTransform(Visual) Method

Definition

Namespace:

System.Windows.Media

Assembly:

PresentationCore.dll

Returns a Transform value for the Visual.

public:
 static System::Windows::Media::Transform ^ GetTransform(System::Windows::Media::Visual ^ reference);

public static System.Windows.Media.Transform GetTransform (System.Windows.Media.Visual reference);

static member GetTransform : System.Windows.Media.Visual -> System.Windows.Media.Transform

Public Shared Function GetTransform (reference As Visual) As Transform

Parameters

reference

Visual

The Visual whose transform value is returned.

Returns

Transform

The transform value of the Visual, or null if reference does not have a transform defined.

Examples

The following code example shows how to use the GetTransform method to retrieve the transform for the specified visual object.

// Return the transform for the specified visual object.
Transform transform = VisualTreeHelper.GetTransform(myDrawing);

// If there is no transform defined for the object, the return value is null.
if (transform != null)
{
    // Return the offset of the returned transform. The offset is relative to the parent of the visual object.
    Point pt = transform.Transform(new Point(0, 0));
}

' Return the transform for the specified visual object.
Dim transform As Transform = VisualTreeHelper.GetTransform(myDrawing)

' If there is no transform defined for the object, the return value is null.
If transform IsNot Nothing Then
    ' Return the offset of the returned transform. The offset is relative to the parent of the visual object.
    Dim pt As Point = transform.Transform(New Point(0, 0))
End If

Your code should test for null before using the returned value. To return the offset of the returned transform, use the Transform method. The offset value is relative to the parent of the Visual.

Remarks

Alternatively, you can use the TransformToAncestor method to return a transform value for the ancestor of a Visual. This method always returns a valid transform. The following code example shows how to use TransformToAncestor method.

// Return the general transform for the specified visual object.
GeneralTransform generalTransform1 = myTextBlock.TransformToAncestor((Visual)myTextBlock.Parent);

// Retrieve the point value relative to the parent.
Point currentPoint = generalTransform1.Transform(new Point(0, 0));

' Return the general transform for the specified visual object.
Dim generalTransform1 As GeneralTransform = myTextBlock.TransformToAncestor(CType(myTextBlock.Parent, Visual))

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