Export (0) Print
Expand All

ScaleTransform Class

Scales an object in the 2-D x-y coordinate system.

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

The ScaleTransform type exposes the following members.

  NameDescription
Public methodScaleTransform()Initializes a new instance of the ScaleTransform class.
Public methodScaleTransform(Double, Double)Initializes a new instance of the ScaleTransform class with the specified x- and y- scale factors. The scale operation is centered on (0,0).
Public methodScaleTransform(Double, Double, Double, Double)Initializes a new instance of the ScaleTransform class that has the specified scale factors and center point.
Top

  NameDescription
Public propertyCanFreezeGets a value that indicates whether the object can be made unmodifiable. (Inherited from Freezable.)
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 propertyDependencyObjectTypeGets the DependencyObjectType that wraps the CLR type of this instance.  (Inherited from DependencyObject.)
Public propertyDispatcherGets the Dispatcher this DispatcherObject is associated with. (Inherited from DispatcherObject.)
Public propertyHasAnimatedPropertiesGets a value that indicates whether one or more AnimationClock objects is associated with any of this object's dependency properties. (Inherited from Animatable.)
Public propertyInverseGets the inverse of this transform, if it exists. (Inherited from Transform.)
Public propertyIsFrozenGets a value that indicates whether the object is currently modifiable. (Inherited from Freezable.)
Public propertyIsSealedGets a value that indicates whether this instance is currently sealed (read-only). (Inherited from DependencyObject.)
Public propertyScaleXGets or sets the x-axis scale factor.
Public propertyScaleYGets or sets the y-axis scale factor.
Public propertyValueGets the current scaling transformation as a Matrix object. (Overrides Transform.Value.)
Top

  NameDescription
Public methodApplyAnimationClock(DependencyProperty, AnimationClock)Applies an AnimationClock to the specified DependencyProperty. If the property is already animated, the SnapshotAndReplace handoff behavior is used. (Inherited from Animatable.)
Public methodApplyAnimationClock(DependencyProperty, AnimationClock, HandoffBehavior)Applies an AnimationClock to the specified DependencyProperty. If the property is already animated, the specified HandoffBehavior is used. (Inherited from Animatable.)
Public methodBeginAnimation(DependencyProperty, AnimationTimeline)Applies an animation to the specified DependencyProperty. The animation is started when the next frame is rendered. If the specified property is already animated, the SnapshotAndReplace handoff behavior is used. (Inherited from Animatable.)
Public methodBeginAnimation(DependencyProperty, AnimationTimeline, HandoffBehavior)Applies an animation to the specified DependencyProperty. The animation is started when the next frame is rendered. If the specified property is already animated, the specified HandoffBehavior is used. (Inherited from Animatable.)
Public methodCheckAccessDetermines whether the calling thread has access to this DispatcherObject. (Inherited from DispatcherObject.)
Public methodClearValue(DependencyProperty)Clears the local value of a property. The property to be cleared is specified by a DependencyProperty identifier. (Inherited from DependencyObject.)
Public methodClearValue(DependencyPropertyKey)Clears the local value of a read-only property. The property to be cleared is specified by a DependencyPropertyKey. (Inherited from DependencyObject.)
Public methodCloneCreates a modifiable copy of this ScaleTransform by making deep copies of its values.
Public methodCloneCurrentValueCreates a modifiable copy of this ScaleTransform object by making deep copies of its values. This method does not copy resource references, data bindings, or animations, although it does copy their current values.
Public methodCoerceValueCoerces the value of the specified dependency property. This is accomplished by invoking any CoerceValueCallback function specified in property metadata for the dependency property as it exists on the calling DependencyObject. (Inherited from DependencyObject.)
Public methodEqualsDetermines whether a provided DependencyObject is equivalent to the current DependencyObject. (Inherited from DependencyObject.)
Public methodFreeze()Makes the current object unmodifiable and sets its IsFrozen property to true. (Inherited from Freezable.)
Public methodGetAnimationBaseValueReturns the non-animated value of the specified DependencyProperty. (Inherited from Animatable.)
Public methodGetAsFrozenCreates a frozen copy of the Freezable, using base (non-animated) property values. Because the copy is frozen, any frozen sub-objects are copied by reference. (Inherited from Freezable.)
Public methodGetCurrentValueAsFrozenCreates a frozen copy of the Freezable using current property values. Because the copy is frozen, any frozen sub-objects are copied by reference. (Inherited from Freezable.)
Public methodGetHashCodeGets a hash code for this DependencyObject. (Inherited from DependencyObject.)
Public methodGetLocalValueEnumeratorCreates a specialized enumerator for determining which dependency properties have locally set values on this DependencyObject. (Inherited from DependencyObject.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodGetValueReturns the current effective value of a dependency property on this instance of a DependencyObject. (Inherited from DependencyObject.)
Public methodInvalidatePropertyRe-evaluates the effective value for the specified dependency property (Inherited from DependencyObject.)
Public methodReadLocalValueReturns the local value of a dependency property, if it exists. (Inherited from DependencyObject.)
Public methodSetCurrentValueSets the value of a dependency property without changing its value source. (Inherited from DependencyObject.)
Public methodSetValue(DependencyProperty, Object)Sets the local value of a dependency property, specified by its dependency property identifier. (Inherited from DependencyObject.)
Public methodSetValue(DependencyPropertyKey, Object)Sets the local value of a read-only dependency property, specified by the DependencyPropertyKey identifier of the dependency property. (Inherited from DependencyObject.)
Protected methodShouldSerializePropertyReturns a value that indicates whether serialization processes should serialize the value for the provided dependency property. (Inherited from DependencyObject.)
Public methodToString()Creates a string representation of this GeneralTransform. (Inherited from GeneralTransform.)
Public methodToString(IFormatProvider)Creates a string representation of this instance, based on the passed IFormatProvider parameter. (Inherited from GeneralTransform.)
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.)
Public methodVerifyAccessEnforces that the calling thread has access to this DispatcherObject. (Inherited from DispatcherObject.)
Top

  NameDescription
Public eventChangedOccurs when the Freezable or an object it contains is modified. (Inherited from Freezable.)
Top

  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.
Top

  NameDescription
Explicit interface implemetationPrivate methodIFormattable.ToStringFormats the value of the current instance using the specified format. (Inherited from GeneralTransform.)
Top

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

Freezable Features: Because it inherits from the Freezable class, the ScaleTransform class provides several special features: ScaleTransform objects can be declared as resources, shared among multiple objects, made read-only to improve performance, cloned, and made thread-safe. For more information about the different features provided by Freezable objects, see Freezable Objects Overview.

This example shows how to use a ScaleTransform to scale an element.

Use the ScaleX and ScaleY properties to resize the element by the factor you specify. For example, a ScaleX value of 1.5 stretches the element to 150 percent of its original width. A ScaleY value of 0.5 shrinks the height of an element by 50 percent.

Use the CenterX and CenterY properties to specify the point that is the center of the scale operation. By default, a ScaleTransform is centered at the point (0,0), which corresponds to the upper-left corner of the rectangle. This has the effect of moving the element and also of making it appear larger, because when you apply a Transform, you change the coordinate space in which the object resides.

The following example uses a ScaleTransform to double the size of a 50-by-50 Rectangle. The ScaleTransform has a value of 0 (the default) for both CenterX and CenterY.

<!-- Scales a rectangle by 200% from a center of (0,0).-->
<Rectangle Height="50" Width="50" Fill="#CCCCCCFF" 
  Stroke="Blue" StrokeThickness="2"
  Canvas.Left="100" Canvas.Top="100">
  <Rectangle.RenderTransform>
    <ScaleTransform CenterX="0" CenterY="0" ScaleX="2" ScaleY="2" />
  </Rectangle.RenderTransform>
</Rectangle>

Typically, you set CenterX and CenterY to the center of the object that is scaled: (Width/2, Height/2).

The following example shows another Rectangle that is doubled in size; however, this ScaleTransform has a value of 25 for both CenterX and CenterY, which corresponds to the center of the rectangle.

<!-- Scales a rectangle by 200% from a center of (25,25).-->
<Rectangle Height="50" Width="50" Fill="#CCCCCCFF"
  Canvas.Left="100" Canvas.Top="100" Stroke="Blue" StrokeThickness="2">
  <Rectangle.RenderTransform>
    <ScaleTransform CenterX="25" CenterY="25" ScaleX="2" ScaleY="2" />
  </Rectangle.RenderTransform>
</Rectangle>

The following illustration shows the difference between the two ScaleTransform operations. The dotted line shows the size and position of the rectangle before scaling.

Two ScaleTransform operations with identical ScaleX and ScaleY values but different centers

2x scales with different center points

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

More Code

How to: Flip a UIElement Horizontally or VerticallyThis example shows how to use a ScaleTransform to flip a UIElement horizontally or vertically. In this example, a Button control (a type of UIElement) is flipped by applying a ScaleTransform to its RenderTransform property.
How to: Animate the Size of a FrameworkElementTo animate the size of a FrameworkElement, you can either animate its Width and Height properties or use an animated ScaleTransform.
How to: Apply a Transform to an Element When an Event OccursThis example shows how to apply a ScaleTransform when an event occurs. The concept that is shown here is the same that you use for applying other types of transformations. For more information about the available types of transformations, see the Transform class or Transforms Overview.

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Show:
© 2014 Microsoft