Manages states and the logic for transitioning between states for controls.
Assembly: PresentationFramework (in PresentationFramework.dll)
XMLNS for XAML: http://schemas.microsoft.com/winfx/2006/xaml/presentation, http://schemas.microsoft.com/netfx/2007/xaml/presentation
Thetype exposes the following members.
|DependencyObjectType||Gets the DependencyObjectType that wraps the CLR type of this instance. (Inherited from DependencyObject.)|
|Dispatcher||Gets the Dispatcher this DispatcherObject is associated with. (Inherited from DispatcherObject.)|
|IsSealed||Gets a value that indicates whether this instance is currently sealed (read-only). (Inherited from DependencyObject.)|
|CheckAccess||Determines whether the calling thread has access to this DispatcherObject. (Inherited from DispatcherObject.)|
|ClearValue(DependencyProperty)||Clears the local value of a property. The property to be cleared is specified by a DependencyProperty identifier. (Inherited from DependencyObject.)|
|ClearValue(DependencyPropertyKey)||Clears the local value of a read-only property. The property to be cleared is specified by a DependencyPropertyKey. (Inherited from DependencyObject.)|
|CoerceValue||Coerces 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.)|
|Equals||Determines whether a provided DependencyObject is equivalent to the current DependencyObject. (Inherited from DependencyObject.)|
|Finalize||Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)|
|GetCustomVisualStateManager||Gets the CustomVisualStateManager attached property.|
|GetHashCode||Gets a hash code for this DependencyObject. (Inherited from DependencyObject.)|
|GetLocalValueEnumerator||Creates a specialized enumerator for determining which dependency properties have locally set values on this DependencyObject. (Inherited from DependencyObject.)|
|GetType||Gets the Type of the current instance. (Inherited from Object.)|
|GetValue||Returns the current effective value of a dependency property on this instance of a DependencyObject. (Inherited from DependencyObject.)|
|GetVisualStateGroups||Gets the VisualStateManager.VisualStateGroups attached property.|
|GoToElementState||Transitions the element between two states. Use this method to transition states that are defined by an application, rather than defined by a control.|
|GoToState||Transitions the control between two states. Use this method to transition states on control that has a ControlTemplate.|
|GoToStateCore||Transitions a control between states.|
|InvalidateProperty||Re-evaluates the effective value for the specified dependency property (Inherited from DependencyObject.)|
|MemberwiseClone||Creates a shallow copy of the current Object. (Inherited from Object.)|
|OnPropertyChanged||Invoked whenever the effective value of any dependency property on this DependencyObject has been updated. The specific dependency property that changed is reported in the event data. (Inherited from DependencyObject.)|
|RaiseCurrentStateChanged||Raises the CurrentStateChanging event on the specified VisualStateGroup object.|
|RaiseCurrentStateChanging||Raises the CurrentStateChanging event on the specified VisualStateGroup object.|
|ReadLocalValue||Returns the local value of a dependency property, if it exists. (Inherited from DependencyObject.)|
|SetCurrentValue||Sets the value of a dependency property without changing its value source. (Inherited from DependencyObject.)|
|SetCustomVisualStateManager||Sets the CustomVisualStateManager attached property.|
|SetValue(DependencyProperty, Object)||Sets the local value of a dependency property, specified by its dependency property identifier. (Inherited from DependencyObject.)|
|SetValue(DependencyPropertyKey, Object)||Sets the local value of a read-only dependency property, specified by the DependencyPropertyKey identifier of the dependency property. (Inherited from DependencyObject.)|
|ShouldSerializeProperty||Returns a value that indicates whether serialization processes should serialize the value for the provided dependency property. (Inherited from DependencyObject.)|
|ToString||Returns a string that represents the current object. (Inherited from Object.)|
|VerifyAccess||Enforces that the calling thread has access to this DispatcherObject. (Inherited from DispatcherObject.)|
The enables you to specify states for a control, the appearance of a control when it is in a certain state, and when a control changes states. For example, a Button might have a slightly different appearance when it is pressed than when it is not pressed. Two states that the Button defines correspond to when it is pressed ("Pressed") and when it is not ("Normal"). The appearance of a control when it is in a state is defined by a VisualState. A VisualState contains a collection of Storyboard objects that specify how the control's appearance changes when the control is in that state. You add visual states to a control by setting the VisualStateManager.VisualStateGroups attached property on the control. Each VisualStateGroup contains a collection of VisualState objects that are mutually exclusive. That is, the control is always in exactly one state of in each VisualStateGroup.
The also enables you to specify when a control enters a specific state. The method that you should call to change states depends on your scenario. If you create a control that uses the in its ControlTemplate, call the GoToState method. For more information about how to create controls that use the , see Creating a Control That Has a Customizable Appearance. If you use the outside of a ControlTemplate (for example, if you use a in a UserControl or in a single element), call the GoToElementState method. In either case, the performs the logic that is required to appropriately start and stop the storyboards that are associated with the involved state. For example, suppose that a control defines the states, State1 and State2, each of which has a storyboard associated with it. If the control is in State1 and you pass State2 to GoToState or GoToElementState, the starts the storyboard in State2 and stops the storyboard in State1.
Controls that are included with Windows Presentation Foundation (WPF) use the to change visual states. When you create a ControlTemplate for a control that is included with WPF, you can add VisualState objects to the control's ControlTemplate to specify the control's appearance in a certain state. To find the names of the visual states for the controls that are included with WPF, see Control Styles and Templates. The control's logic handles transitioning between states, so you do not need to do anything other than define the VisualState objects in the new ControlTemplate. For more information about how to create control templates for existing controls, see Customizing the Appearance of an Existing Control by Creating a ControlTemplate.
If you want to implement your own logic for transitioning between states, you must inherit from , override the GoToStateCore method, and set the VisualStateManager.CustomVisualStateManager attached property on the control that uses the custom logic.
The following example creates a Rectangle and adds a VisualStateGroup named CommonStates to the VisualStateManager.VisualStatesGroups attached property. The example defines the MouseOver and Normal VisualState objects in the CommonStates VisualStateGroup. When the user moves the mouse pointer over the Rectangle, it changes from red to green over one half second. When the user moves the mouse away from the rectangle, the Grid immediately changes back to red. Note that the Normal state does not define a Storyboard. A Storyboard is not required because when the Rectangle transitions from the MouseOver state to the Normal state, the Storyboard for MouseOver is stopped and the Color property for the SolidColorBrush returns to red.
<Rectangle Name="rect" Width="100" Height="100" MouseEnter="rect_MouseEvent" MouseLeave="rect_MouseEvent"> <VisualStateManager.VisualStateGroups> <VisualStateGroup Name="MouseStates"> <VisualState Name="MouseEnter"> <Storyboard> <ColorAnimation To="Green" Storyboard.TargetName="rectBrush" Storyboard.TargetProperty="Color"/> </Storyboard> </VisualState> <VisualState Name="MouseLeave" /> <VisualStateGroup.Transitions> <VisualTransition To="MouseLeave" GeneratedDuration="00:00:00"/> <VisualTransition To="MouseEnter" GeneratedDuration="00:00:00.5"> <VisualTransition.GeneratedEasingFunction> <ExponentialEase EasingMode="EaseOut" Exponent="10"/> </VisualTransition.GeneratedEasingFunction> </VisualTransition> </VisualStateGroup.Transitions> </VisualStateGroup> </VisualStateManager.VisualStateGroups> <Rectangle.Fill> <SolidColorBrush x:Name="rectBrush" Color="Red"/> </Rectangle.Fill> </Rectangle>
The following example shows the event handler that is defined in the previous example and calls the GoToElementState method to transition between states. If the rectangle in the previous example was part of a ControlTemplate, the example would have to call the GoToState method.