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RotateTransform::CenterY Property

Gets or sets the y-coordinate of the rotation center point.

Namespace:  System.Windows.Media
Assembly:  PresentationCore (in PresentationCore.dll)
XMLNS for XAML: http://schemas.microsoft.com/winfx/2006/xaml/presentation, http://schemas.microsoft.com/netfx/2007/xaml/presentation

public:
property double CenterY {
	double get ();
	void set (double value);
}
<object CenterY="double" .../>

Property Value

Type: System::Double
The y-coordinate of the center of rotation. The default is 0.

Identifier field

CenterYProperty

Metadata properties set to true

None

When you use a RotateTransform, realize that the transformation rotates the coordinate system for a particular object about the point (0, 0). Therefore, depending on the position of the object, it might not rotate in place (around its center). For example, if an object is positioned 200 units from 0 along the x-axis, a rotation of 30 degrees can swing the object 30 degrees along a circle that has a radius of 200, which is drawn around the origin. To rotate an object in place, set the CenterX and CenterY of the RotateTransform to the center of the object to rotate.

This example shows how to rotate an object. The example first creates a RotateTransform and then specifies its Angle in degrees.

The following example rotates a Polyline object 45 degrees about its upper-left corner.


<Canvas Height="200" Width="200">

  <!-- Rotates the Polyline 45 degrees about the point (0,0). -->
  <Polyline Points="25,25 0,50 25,75 50,50 25,25 25,0" 
    Stroke="Blue" StrokeThickness="10"
    Canvas.Left="75" Canvas.Top="50">
    <Polyline.RenderTransform>
      <RotateTransform CenterX="0" CenterY="0" Angle="45" />
    </Polyline.RenderTransform>
  </Polyline>
</Canvas>


No code example is currently available or this language may not be supported.

The CenterX and CenterY properties of the RotateTransform specify the point about which the object is rotated. This center point is expressed in the coordinate space of the element that is transformed. By default, the rotation is applied to (0,0), which is the upper-left corner of the object to transform.

The next example rotates a Polyline object clockwise 45 degrees about the point (25,50).


<Canvas Height="200" Width="200">

  <!-- Rotates the Polyline 45 degrees about the point (25,50). -->
  <Polyline Points="25,25 0,50 25,75 50,50 25,25 25,0" 
    Stroke="Blue" StrokeThickness="10"
    Canvas.Left="75" Canvas.Top="50">
    <Polyline.RenderTransform>
      <RotateTransform CenterX="25" CenterY="50" Angle="45" />
    </Polyline.RenderTransform>
  </Polyline>
</Canvas>


No code example is currently available or this language may not be supported.

The following illustration shows the results of applying a Transform to the two objects.

Two objects that rotate 45 degrees from different rotational centers

45 degree rotations with different center points

The Polyline in the previous examples is a UIElement. When you apply a Transform to the RenderTransform property of a UIElement, you can use the RenderTransformOrigin property to specify an origin for every Transform that you apply to the element. Because the RenderTransformOrigin property uses relative coordinates, you can apply a transformation to the center of the element even if you do not know its size. For more information and for an example, see How to: Specify the Origin of a Transform by Using Relative Values.

For the complete sample, see 2-D Transforms Sample.

More Code

How to: Make an Element Spin in PlaceThis example shows how to make an element spin by using a RotateTransform and a DoubleAnimation.

.NET Framework

Supported in: 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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