UIElement.RenderTransformOrigin Property

Definition

Namespace:

System.Windows

Assembly:

PresentationCore.dll

Gets or sets the center point of any possible render transform declared by RenderTransform, relative to the bounds of the element. This is a dependency property.

public:
 property System::Windows::Point RenderTransformOrigin { System::Windows::Point get(); void set(System::Windows::Point value); };

public System.Windows.Point RenderTransformOrigin { get; set; }

member this.RenderTransformOrigin : System.Windows.Point with get, set

Public Property RenderTransformOrigin As Point

Property Value

Point

The value that declares the render transform. The default value is a Point with coordinates (0,0).

Examples

The following example builds up elements in code, applies a RenderTransformOrigin, and then applies a RenderTransform.

public RotateAboutCenterExample()
{
    this.WindowTitle = "Rotate About Center Example";
    NameScope.SetNameScope(this, new NameScope());
    StackPanel myStackPanel = new StackPanel();
    myStackPanel.Margin = new Thickness(50);

    Button myButton = new Button();
    myButton.Name = "myRenderTransformButton";
    this.RegisterName(myButton.Name,myButton);
    myButton.RenderTransformOrigin = new Point(0.5,0.5);
    myButton.HorizontalAlignment = HorizontalAlignment.Left;
    myButton.Content = "Hello World";

    RotateTransform myRotateTransform = new RotateTransform(0);
    myButton.RenderTransform = myRotateTransform;
    this.RegisterName("MyAnimatedTransform",myRotateTransform);

    myStackPanel.Children.Add(myButton);

    //
    // Creates an animation that accelerates through 40% of its duration and
    //      decelerates through the 60% of its duration.
    //
    DoubleAnimation myRotateAboutCenterAnimation = new DoubleAnimation();
    Storyboard.SetTargetName(myRotateAboutCenterAnimation,"MyAnimatedTransform");
    Storyboard.SetTargetProperty(myRotateAboutCenterAnimation,new PropertyPath(RotateTransform.AngleProperty));
    myRotateAboutCenterAnimation.From = 0.0;
    myRotateAboutCenterAnimation.To = 360;
    myRotateAboutCenterAnimation.Duration = new Duration(TimeSpan.FromMilliseconds(1000));

    // Create a Storyboard to contain the animations and
    // add the animations to the Storyboard.
    Storyboard myStoryboard = new Storyboard();
    myStoryboard.Children.Add(myRotateAboutCenterAnimation);

    // Create an EventTrigger and a BeginStoryboard action to
    // start the storyboard.
    EventTrigger myEventTrigger = new EventTrigger();
    myEventTrigger.RoutedEvent = Button.ClickEvent;
    myEventTrigger.SourceName = myButton.Name;
    BeginStoryboard myBeginStoryboard = new BeginStoryboard();
    myBeginStoryboard.Storyboard = myStoryboard;
    myEventTrigger.Actions.Add(myBeginStoryboard);
    myStackPanel.Triggers.Add(myEventTrigger);

    this.Content = myStackPanel;
}

Public Sub New()
    Me.WindowTitle = "Rotate About Center Example"
    NameScope.SetNameScope(Me, New NameScope())
    Dim myStackPanel As New StackPanel()
    myStackPanel.Margin = New Thickness(50)

    Dim myButton As New Button()
    myButton.Name = "myRenderTransformButton"
    Me.RegisterName(myButton.Name,myButton)
    myButton.RenderTransformOrigin = New Point(0.5,0.5)
    myButton.HorizontalAlignment = HorizontalAlignment.Left
    myButton.Content = "Hello World"


    Dim myRotateTransform As New RotateTransform(0)
    myButton.RenderTransform = myRotateTransform
    Me.RegisterName("MyAnimatedTransform",myRotateTransform)

    myStackPanel.Children.Add(myButton)

    '
    ' Creates an animation that accelerates through 40% of its duration and
    '      decelerates through the 60% of its duration.
    '
    Dim myRotateAboutCenterAnimation As New DoubleAnimation()
    Storyboard.SetTargetName(myRotateAboutCenterAnimation,"MyAnimatedTransform")
    Storyboard.SetTargetProperty(myRotateAboutCenterAnimation,New PropertyPath(RotateTransform.AngleProperty))
    myRotateAboutCenterAnimation.From = 0.0
    myRotateAboutCenterAnimation.To = 360
    myRotateAboutCenterAnimation.Duration = New Duration(TimeSpan.FromMilliseconds(1000))

    ' Create a Storyboard to contain the animations and
    ' add the animations to the Storyboard.
    Dim myStoryboard As New Storyboard()
    myStoryboard.Children.Add(myRotateAboutCenterAnimation)

    ' Create an EventTrigger and a BeginStoryboard action to
    ' start the storyboard.
    Dim myEventTrigger As New EventTrigger()
    myEventTrigger.RoutedEvent = Button.ClickEvent
    myEventTrigger.SourceName = myButton.Name
    Dim myBeginStoryboard As New BeginStoryboard()
    myBeginStoryboard.Storyboard = myStoryboard
    myEventTrigger.Actions.Add(myBeginStoryboard)
    myStackPanel.Triggers.Add(myEventTrigger)

    Me.Content = myStackPanel
End Sub

Remarks

RenderTransformOrigin has a somewhat nonstandard use of the Point structure value, in that the Point does not represent an absolute location in a coordinate system. Instead, values between 0 and 1 are interpreted as a factor for the range of the current element in each x,y axis. For example, (0.5,0.5) will cause the render transform to be centered on the element, or (1,1) would place the render transform at the bottom right corner of the element. NaN is not an accepted value.

Values beyond 0 and 1 are also accepted, and will result in more unconventional transform effects. For instance, if you set RenderTransformOrigin to be (5,5), and then apply a RotateTransform, the rotation point will be well outside the bounds of the element itself. The transform will spin your element around in a big circle that originates beyond bottom right. The origin might be somewhere inside its parent element and could possibly be possibly out of frame or view. Negative point values are similar, these will go beyond the top left bounds.

Render transforms do not affect layout, and are typically used to animate or apply a temporary effect to an element.

XAML Attribute Usage

<object RenderTransformOrigin="xOrigin, yOrigin"/>  

XAML Property Element Usage

<object>  
  <object.RenderTransformOrigin>  
    <Point X=" xOrigin " Y=" yOrigin "/>  
  </object.RenderTransformOrigin>  
</object>  

XAML Values

xOrigin
The horizontal origin factor. This is typically given as a value between 0 and 1. See Remarks.

yOrigin
The vertical origin factor. This is typically given as a value between 0 and 1. See Remarks.

Dependency Property Information

Identifier field	RenderTransformOriginProperty
Metadata properties set to true	None

See also

• RenderTransform