ScaleTransform Class

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

Scales an object in the two-dimensional x-y coordinate system.

Inheritance Hierarchy

System..::.Object
System.Windows..::.DependencyObject
System.Windows.Media..::.GeneralTransform
System.Windows.Media..::.Transform
System.Windows.Media..::.ScaleTransform

Namespace: System.Windows.Media
Assembly: System.Windows (in System.Windows.dll)
XMLNS for XAML: Not mapped to an xmlns.

Syntax

Public NotInheritable Class ScaleTransform _
    Inherits Transform
public sealed class ScaleTransform : Transform
<ScaleTransform .../>

The ScaleTransform type exposes the following members.

Constructors

Name Description
ScaleTransform Initializes a new instance of the ScaleTransform class.

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Properties

Name Description
CenterX Gets or sets the x-coordinate of the center point of this ScaleTransform.
CenterY Gets or sets the y-coordinate of the center point of this ScaleTransform.
Dispatcher Gets the Dispatcher this object is associated with. (Inherited from DependencyObject.)
Inverse Gets the inverse of this transform, if it exists. (Inherited from Transform.)
ScaleX Gets or sets the x-axis scale factor.
ScaleY Gets or sets the y-axis scale factor.

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Methods

Name Description
CheckAccess Determines whether the calling thread has access to this object. (Inherited from DependencyObject.)
ClearValue Clears the local value of a dependency property. (Inherited from DependencyObject.)
Equals(Object) Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Finalize Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
GetAnimationBaseValue Returns any base value established for a Windows Phone dependency property, which would apply in cases where an animation is not active. (Inherited from DependencyObject.)
GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
GetType Gets the Type of the current instance. (Inherited from Object.)
GetValue Returns the current effective value of a dependency property from a DependencyObject. (Inherited from DependencyObject.)
MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
ReadLocalValue Returns the local value of a dependency property, if a local value is set. (Inherited from DependencyObject.)
SetValue Sets the local value of a dependency property on a DependencyObject. (Inherited from DependencyObject.)
ToString Returns a string that represents the current object. (Inherited from Object.)
Transform Transforms the specified point and returns the result. (Inherited from GeneralTransform.)
TransformBounds Transforms the specified bounding box and returns an axis-aligned bounding box that is exactly large enough to contain it. (Inherited from Transform.)
TryTransform Attempts to transform the specified point and returns a value that indicates whether the transformation was successful. (Inherited from Transform.)

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Fields

Name Description
CenterXProperty Identifies the CenterX dependency property.
CenterYProperty Identifies the CenterY dependency property.
ScaleXProperty Identifies the ScaleX dependency property.
ScaleYProperty Identifies the ScaleY dependency property.

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Remarks

Use a ScaleTransform to stretch or shrink an object horizontally or vertically. The ScaleX property specifies the amount to stretch or shrink an object along the x-axis, and the ScaleY property specifies the amount to stretch or shrink an object along the y-axis. Scale operations are centered on the point specified by the CenterX and CenterY properties.

The local 0,0 for an object can be offset on a Canvas using Canvas..::.Left and Canvas..::.Top, but this does not count as a transform; the object retains its own local 0,0 in this case for transform purposes.

Multiple transforms can be applied with a TransformGroup. Custom transforms can be created with a MatrixTransform.

Transforms can alter the display of text in your application to create a decorative effect. The following illustration shows the second line of text scaled by 150% along the x-axis, and the third line of text scaled by 150% along the y-axis.

TextBlock using a ScaleTransform

Note

Scaling text is not the same as increasing the font size of text. Font sizes are calculated independently of each other in order to provide the best resolution at different sizes. Scaled text, on the other hand, preserves the proportions of the original-sized text.

Examples

The following XAML example uses a ScaleTransform to scale text from its original size.

<StackPanel>
<TextBlock
  FontFamily="Verdana"
  FontSize="32"
  FontWeight="Bold" 
  Foreground="SteelBlue"
  Text="Scaled Text" />

<!-- Scale the text width using a ScaleTransform. -->
<TextBlock
  FontFamily="Verdana"
  FontSize="32"
  FontWeight="Bold" 
  Foreground="SteelBlue"
  Text="Scaled Text">
  <TextBlock.RenderTransform>
    <ScaleTransform ScaleX="1.5" ScaleY="1.0" />
  </TextBlock.RenderTransform>
</TextBlock>

<!-- Scale the text height using a ScaleTransform. -->
<TextBlock
  FontFamily="Verdana"
  FontSize="32"
  FontWeight="Bold" 
  Foreground="SteelBlue"
  Text="Scaled Text">
  <TextBlock.RenderTransform>
    <ScaleTransform ScaleX="1.0" ScaleY="1.5" />
  </TextBlock.RenderTransform>
</TextBlock>
</StackPanel>

Transform objects can be accessed and manipulated by using code. One way to do this is to name the Transform and then access it by using code. The following example shows how to increase the ScaleX and ScaleY property values of a ScaleTransform applied to a Rectangle every time that Rectangle is clicked.

<StackPanel>
  <Rectangle MouseLeftButtonDown="HandleMouseButtonDown"
    Width="50" Height="50" Fill="RoyalBlue">
    <Rectangle.RenderTransform>

      <!-- If you give the transform a name you can 
        access it easily from code. -->
      <ScaleTransform x:Name="myScaleTransform" />
    </Rectangle.RenderTransform>
  </Rectangle>
</StackPanel>
Private Sub HandleMouseButtonDown(ByVal sender As Object, ByVal e As MouseButtonEventArgs)
    ' Increase ScaleX and ScaleY by 25%.
    myScaleTransform.ScaleX = (myScaleTransform.ScaleX * 1.25)
    myScaleTransform.ScaleY = (myScaleTransform.ScaleY * 1.25)
End Sub
private void HandleMouseButtonDown(object sender, MouseButtonEventArgs e)
{
    // Increase ScaleX and ScaleY by 25%.
    myScaleTransform.ScaleX = myScaleTransform.ScaleX * 1.25;
    myScaleTransform.ScaleY = myScaleTransform.ScaleY * 1.25;
}

Version Information

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Platforms

Windows Phone

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

See Also

Reference

System.Windows.Media Namespace

ScaleX

ScaleY

CenterX

CenterY