Articolo
11/18/2011

VisualStateGroup Class

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Contains mutually exclusive VisualState objects and VisualTransition objects that are used to go from one state to another.

Inheritance Hierarchy

System.Object
System.Windows.DependencyObject
System.Windows.VisualStateGroup

Namespace: System.Windows
Assembly: System.Windows (in System.Windows.dll)

Syntax

'Declaration
<ContentPropertyAttribute("States", True)> _
Public NotInheritable Class VisualStateGroup _
    Inherits DependencyObject

[ContentPropertyAttribute("States", true)]
public sealed class VisualStateGroup : DependencyObject

<VisualStateManager.VisualStateGroups>
   <VisualStateGroup ...>
</VisualStateManager.VisualStateGroups>

The VisualStateGroup type exposes the following members.

Constructors

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

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Properties

	Name	Description
	CurrentState	Gets the most recently set VisualState from a successful call to the GoToState method.
	Dispatcher	Gets the Dispatcher this object is associated with. (Inherited from DependencyObject.)
	Name	Gets the name of the VisualStateGroup.
	States	Gets the collection of mutually exclusive VisualState objects.
	Transitions	Gets the collection of VisualTransition objects.

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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 Silverlight 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.)

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Events

	Name	Description
	CurrentStateChanged	Occurs after a control transitions into a different state.
	CurrentStateChanging	Occurs when a control begins transitioning into a different state.

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Remarks

ControlTemplate authors VisualState objects to a VisualStateGroup in a ControlTemplate to specify the visual behavior of the control. You put states that are mutually exclusive to each other in the same VisualStateGroup. For example, the CheckBox has two VisualStateGroup objects. One contains the states, Normal, MouseOver, Pressed, and Disabled. The other contains the states, Checked, UnChecked, and Indeterminate. The CheckBox can be in states MouseOver and UnChecked at the same time, but it cannot be in the MouseOver and Pressed states at the same time.

Control authors specify which states the control can be in by putting the TemplateVisualStateAttribute, on its class definition. States with the same TemplateVisualStateAttribute.GroupName belong in the same VisualStateGroup.

The Transitions property contains VisualTransition objects that are applied when the control transition between states that are defined in the VisualStateGroup.

For more information about using VisualStateGroup objects in a ControlTemplate, see Customizing the Appearance of an Existing Control by Using a ControlTemplate.

Examples

The following example creates a simple ControlTemplate for a Button that contains one Grid. It also contains a VisualStateGroup called CommonStates, which defines the MouseOver and Normal states. The VisualStateGroup also has a VisualTransition that specifies that it takes one half second for the Grid to change from green to red when the user puts the mouse over the Button.

Run this sample

<ControlTemplate TargetType="Button">
  <Grid >
    <VisualStateManager.VisualStateGroups>
      <VisualStateGroup x:Name="CommonStates">

        <VisualStateGroup.Transitions>

          <!--Take one half second to trasition to the MouseOver state.-->
          <VisualTransition To="MouseOver" 
                              GeneratedDuration="0:0:0.5"/>
        </VisualStateGroup.Transitions>

        <VisualState x:Name="Normal" />

        <!--Change the SolidColorBrush, ButtonBrush, to red when the
            mouse is over the button.-->
        <VisualState x:Name="MouseOver">
          <Storyboard>
            <ColorAnimation Storyboard.TargetName="ButtonBrush" 
                            Storyboard.TargetProperty="Color" To="Red" />
          </Storyboard>
        </VisualState>
      </VisualStateGroup>
    </VisualStateManager.VisualStateGroups>
    <Grid.Background>
      <SolidColorBrush x:Name="ButtonBrush" Color="Green"/>
    </Grid.Background>
  </Grid>
</ControlTemplate>

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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.

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