ScaleTransform Class

May 11, 2014

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

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

public sealed class ScaleTransform : Transform
<ScaleTransform .../>

The ScaleTransform type exposes the following members.

  NameDescription
Public methodScaleTransformInitializes a new instance of the ScaleTransform class.
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  NameDescription
Public propertyCenterXGets or sets the x-coordinate of the center point of this ScaleTransform.
Public propertyCenterYGets or sets the y-coordinate of the center point of this ScaleTransform.
Public propertyDispatcherGets the Dispatcher this object is associated with. (Inherited from DependencyObject.)
Public propertyInverseGets the inverse of this transform, if it exists. (Inherited from Transform.)
Public propertyScaleXGets or sets the x-axis scale factor.
Public propertyScaleYGets or sets the y-axis scale factor.
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  NameDescription
Public methodCheckAccessDetermines whether the calling thread has access to this object. (Inherited from DependencyObject.)
Public methodClearValueClears the local value of a dependency property. (Inherited from DependencyObject.)
Public methodEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetAnimationBaseValueReturns any base value established for a Windows Phone dependency property, which would apply in cases where an animation is not active. (Inherited from DependencyObject.)
Public methodGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodGetValueReturns the current effective value of a dependency property from a DependencyObject. (Inherited from DependencyObject.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodReadLocalValueReturns the local value of a dependency property, if a local value is set. (Inherited from DependencyObject.)
Public methodSetValueSets the local value of a dependency property on a DependencyObject. (Inherited from DependencyObject.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
Public methodTransformTransforms the specified point and returns the result. (Inherited from GeneralTransform.)
Public methodTransformBoundsTransforms the specified bounding box and returns an axis-aligned bounding box that is exactly large enough to contain it. (Inherited from Transform.)
Public methodTryTransformAttempts to transform the specified point and returns a value that indicates whether the transformation was successful. (Inherited from Transform.)
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  NameDescription
Public fieldStatic memberCenterXPropertyIdentifies the CenterX dependency property.
Public fieldStatic memberCenterYPropertyIdentifies the CenterY dependency property.
Public fieldStatic memberScaleXPropertyIdentifies the ScaleX dependency property.
Public fieldStatic memberScaleYPropertyIdentifies the ScaleY dependency property.
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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

Transformed text.
NoteNote:

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.

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 void HandleMouseButtonDown(object sender, MouseButtonEventArgs e)
{
    // Increase ScaleX and ScaleY by 25%.
    myScaleTransform.ScaleX = myScaleTransform.ScaleX * 1.25;
    myScaleTransform.ScaleY = myScaleTransform.ScaleY * 1.25;
}


Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

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

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