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11/18/2011

FrameworkElementAutomationPeer Class

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Exposes FrameworkElement types (including controls) to UI automation.

Inheritance Hierarchy

System.Object
  System.Windows.DependencyObject
    System.Windows.Automation.Peers.AutomationPeer
      System.Windows.Automation.Peers.FrameworkElementAutomationPeer
        More...

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

Syntax

'Declaration
Public Class FrameworkElementAutomationPeer _
    Inherits AutomationPeer

public class FrameworkElementAutomationPeer : AutomationPeer

The FrameworkElementAutomationPeer type exposes the following members.

Constructors

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

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Properties

	Name	Description
	Dispatcher	Gets the Dispatcher this object is associated with. (Inherited from DependencyObject.)
	EventsSource	Gets or sets an AutomationPeer that is reported to the automation client as a source for all the events that come from this AutomationPeer. (Inherited from AutomationPeer.)
	Owner	Gets the UIElement that is associated with this FrameworkElementAutomationPeer.

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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.)
	CreatePeerForElement	Creates a FrameworkElementAutomationPeer for the specified UIElement.
	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.)
	FromElement	Returns the FrameworkElementAutomationPeer for the specified UIElement.
	GetAcceleratorKey	Gets the accelerator key combination for the object that is associated with the UI Automation peer. (Inherited from AutomationPeer.)
	GetAcceleratorKeyCore	Returns the accelerator key for the UIElement that is associated with this FrameworkElementAutomationPeer. This method is called by GetAcceleratorKey. (Overrides AutomationPeer.GetAcceleratorKeyCore().)
	GetAccessKey	Gets the access key for the object that is associated with the automation peer. (Inherited from AutomationPeer.)
	GetAccessKeyCore	Returns the access key for the UIElement that is associated with this FrameworkElementAutomationPeer. This method is called by GetAccessKey. (Overrides AutomationPeer.GetAccessKeyCore().)
	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.)
	GetAutomationControlType	Gets the control type for the object that is associated with the UI Automation peer. (Inherited from AutomationPeer.)
	GetAutomationControlTypeCore	Returns the control type for the UIElement that is associated with this FrameworkElementAutomationPeer. This method is called by GetAutomationControlType. (Overrides AutomationPeer.GetAutomationControlTypeCore().)
	GetAutomationId	Gets the AutomationId of the object that is associated with the automation peer. (Inherited from AutomationPeer.)
	GetAutomationIdCore	Returns the string that uniquely identifies the FrameworkElement that is associated with this FrameworkElementAutomationPeer. This method is called by GetAutomationId. (Overrides AutomationPeer.GetAutomationIdCore().)
	GetBoundingRectangle	Gets the Rect object that represents the screen coordinates of the element that is associated with the automation peer. (Inherited from AutomationPeer.)
	GetBoundingRectangleCore	Returns the Rect that represents the bounding rectangle of the UIElement that is associated with this FrameworkElementAutomationPeer. This method is called by GetBoundingRectangle. (Overrides AutomationPeer.GetBoundingRectangleCore().)
	GetChildren	Gets the collection of child elements that are represented in the UI Automation tree as immediate child elements of the automation peer. (Inherited from AutomationPeer.)
	GetChildrenCore	Returns the collection of child elements of the UIElement that is associated with this FrameworkElementAutomationPeer. This method is called by GetChildren. (Overrides AutomationPeer.GetChildrenCore().)
	GetClassName	Gets the name of the control class that is associated with the peer. (Inherited from AutomationPeer.)
	GetClassNameCore	Returns the name of the UIElement that is associated with this FrameworkElementAutomationPeer. This method is called by GetClassName. (Overrides AutomationPeer.GetClassNameCore().)
	GetClickablePoint	Gets a Point on the object that is associated with the automation peer that responds to a mouse click. (Inherited from AutomationPeer.)
	GetClickablePointCore	Returns a Point that represents the clickable space that is on the UIElement that is associated with this FrameworkElementAutomationPeer. This method is called by GetClickablePoint. (Overrides AutomationPeer.GetClickablePointCore().)
	GetHashCode	Serves as a hash function for a particular type. (Inherited from Object.)
	GetHelpText	Gets text that describes the functionality of the control that is associated with the automation peer. (Inherited from AutomationPeer.)
	GetHelpTextCore	Returns the string that describes the functionality of the FrameworkElement that is associated with this FrameworkElementAutomationPeer. This method is called by GetHelpText. (Overrides AutomationPeer.GetHelpTextCore().)
	GetItemStatus	Gets text that conveys the visual status of the object that is associated with this automation peer. (Inherited from AutomationPeer.)
	GetItemStatusCore	Returns a string that communicates the visual status of the UIElement that is associated with this FrameworkElementAutomationPeer. This method is called by GetItemStatus. (Overrides AutomationPeer.GetItemStatusCore().)
	GetItemType	Gets a string that describes what kind of item an element represents. (Inherited from AutomationPeer.)
	GetItemTypeCore	Returns a human-readable string that contains the item type that the UIElement for this FrameworkElementAutomationPeer represents. This method is called by GetItemType. (Overrides AutomationPeer.GetItemTypeCore().)
	GetLabeledBy	Gets the AutomationPeer for the UIElement that is targeted to the element. (Inherited from AutomationPeer.)
	GetLabeledByCore	Returns the AutomationPeer for the UIElement that targets the FrameworkElement that is associated with this FrameworkElementAutomationPeer. This method is called by GetLabeledBy. (Overrides AutomationPeer.GetLabeledByCore().)
	GetLocalizedControlType	Gets a localized string that represents the control type, for the control that is associated with this automation peer. The localized string parallels a AutomationControlType value. (Inherited from AutomationPeer.)
	GetLocalizedControlTypeCore	Returns a localized human-readable string that identifies a control type. The control type is for the owner type that is associated with this FrameworkElementAutomationPeer. This method is called by GetLocalizedControlType. (Overrides AutomationPeer.GetLocalizedControlTypeCore().)
	GetName	Gets the value that the automation peer reports as the UI Automation Name for the associated control. (Inherited from AutomationPeer.)
	GetNameCore	Returns the UI Automation Name from the element that is associated with this FrameworkElementAutomationPeer. This method is called by GetName. (Overrides AutomationPeer.GetNameCore().)
	GetOrientation	Gets a value that indicates the explicit control orientation, if any. (Inherited from AutomationPeer.)
	GetOrientationCore	Returns a value that indicates whether the element that is associated with this FrameworkElementAutomationPeer is laid out in a specific direction. This method is called by GetOrientation. (Overrides AutomationPeer.GetOrientationCore().)
	GetParent	Gets the AutomationPeer that is the parent of this AutomationPeer. (Inherited from AutomationPeer.)
	GetPattern	Returns an object that supports the requested pattern, based on the patterns supported by this FrameworkElementAutomationPeer. (Overrides AutomationPeer.GetPattern(PatternInterface).)
	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.)
	HasKeyboardFocus	Gets a value that indicates whether the object that is associated with this automation peer currently has keyboard focus. (Inherited from AutomationPeer.)
	HasKeyboardFocusCore	Returns a value that indicates whether the UIElement that is associated with this FrameworkElementAutomationPeer currently has keyboard input focus. This method is called by HasKeyboardFocus. (Overrides AutomationPeer.HasKeyboardFocusCore().)
	InvalidatePeer	Triggers recalculation of the main properties of the AutomationPeer and raises the PropertyChanged notification to the automation client if the properties have changed. (Inherited from AutomationPeer.)
	IsContentElement	Gets a value that indicates whether the object that is associated with this automation peer contains data that is presented to the user. (Inherited from AutomationPeer.)
	IsContentElementCore	Returns a value that indicates whether the element that is associated with this FrameworkElementAutomationPeer is an element that contains data that is presented to the user. This method is called by IsContentElement. (Overrides AutomationPeer.IsContentElementCore().)
	IsControlElement	Gets a value that indicates whether the element is understood by the user as interactive or as contributing to the logical structure of the control in the GUI. (Inherited from AutomationPeer.)
	IsControlElementCore	Returns a value that indicates whether the object that is associated with this FrameworkElementAutomationPeer is understood by the end user as interactive. Optionally, the user might understand the object as contributing to the logical structure of the control in the GUI. This method is called by IsControlElement. (Overrides AutomationPeer.IsControlElementCore().)
	IsEnabled	Gets a value that indicates whether the element associated with this automation peer supports interaction. (Inherited from AutomationPeer.)
	IsEnabledCore	Returns a value that indicates whether the UIElement that is associated with this FrameworkElementAutomationPeer is enabled. This method is called by IsEnabled. (Overrides AutomationPeer.IsEnabledCore().)
	IsKeyboardFocusable	Gets a value that indicates whether the element can accept keyboard focus. (Inherited from AutomationPeer.)
	IsKeyboardFocusableCore	Returns a value that indicates whether the element that is associated with this FrameworkElementAutomationPeer can accept keyboard focus. This method is called by IsKeyboardFocusable. (Overrides AutomationPeer.IsKeyboardFocusableCore().)
	IsOffscreen	Gets a value that indicates whether an element is off the screen. (Inherited from AutomationPeer.)
	IsOffscreenCore	Returns a value that indicates whether the UIElement that is associated with this FrameworkElementAutomationPeer is off the screen. This method is called by IsOffscreen. (Overrides AutomationPeer.IsOffscreenCore().)
	IsPassword	Gets a value that indicates whether the element contains sensitive content. (Inherited from AutomationPeer.)
	IsPasswordCore	Returns a value that indicates whether the element that is associated with this FrameworkElementAutomationPeer contains protected content. This method is called by IsPassword. (Overrides AutomationPeer.IsPasswordCore().)
	IsRequiredForForm	Gets a value that indicates whether the object that is associated with this peer must be completed on a form. (Inherited from AutomationPeer.)
	IsRequiredForFormCore	Returns a value that indicates whether the element that is associated with this FrameworkElementAutomationPeer is required to be completed on a form. This method is called by IsRequiredForForm. (Overrides AutomationPeer.IsRequiredForFormCore().)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	PeerFromProvider	Gets an AutomationPeer for the specified IRawElementProviderSimple proxy. (Inherited from AutomationPeer.)
	ProviderFromPeer	Gets the IRawElementProviderSimple proxy for the specified AutomationPeer. (Inherited from AutomationPeer.)
	RaiseAutomationEvent	Raises an automation event. (Inherited from AutomationPeer.)
	RaisePropertyChangedEvent	Raises an event to notify the automation client of a changed property value. (Inherited from AutomationPeer.)
	ReadLocalValue	Returns the local value of a dependency property, if a local value is set. (Inherited from DependencyObject.)
	SetFocus	Sets the keyboard focus on the object that is associated with this automation peer. (Inherited from AutomationPeer.)
	SetFocusCore	Sets the keyboard input focus on the element that is associated with this FrameworkElementAutomationPeer. This method is called by SetFocus. (Overrides AutomationPeer.SetFocusCore().)
	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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Remarks

Most controls use this class as the base for their automation peer class. In addition, UI Automation support can be added for classes that are strictly speaking not derived from the Silverlight Control class.

FrameworkElementAutomationPeer *Core Method Implementations

Each of the *Core methods implemented by FrameworkElementAutomationPeer have a simple implementation. These implementations reference native code of the Silverlight codebase. In several cases, the implementations make it possible for the instance-specific AutomationProperties attached property values from XAML and usercode to provide information to an automation peer at runtime.

The FrameworkElementAutomationPeer *Core methods that correspond to a AutomationProperties attached property are as follows:

For example, consider the following XAML: <Button AutomationProperties.Name="Pause"><Image Source="pause.png"/></Button>

This XAML is an example where a button does not have text content, only image content. The application author has specifically added a AutomationProperties.Name attached property value, so that the button has proper human-readable identification for accessibility scenarios such as being represented by a screen reader. In the basic ButtonAutomationPeer implementation, the first thing that the implementation chain does is to call base, which invokes the GetNameCore() method. In this case the GetNameCore() method finds that a value for AutomationProperties.Name exists in the attached property store for this Button instance, and therefore returns that value. The specific ButtonAutomationPeer implementation of GetNameCore is only invoked in the cases where the base returns null. Your own implementations of any *Core method that corresponds to a AutomationProperties attached property should follow this pattern: call base first to make sure that the FrameworkElementAutomationPeer base cannot obtain a runtime value based on instance-specific AutomationProperties values. Only if the base returns null should your *Core implementations attempt to provide a value, as determined either by general values for all class instances, or other instance-specific values that are available through the peer or its owner.

In some cases, a peer should implement a *Core method such that any automation information that exists in an object contained by the owner can be correctly forwarded by the owner's peer. This is the reason why certain "Item" peers such as ItemAutomationPeer override a larger range of *Core methods than a typical Silverlight automation peer does. Depending on your control implementation, it may be worthwhile to base the peer on ItemAutomationPeer to take advantage of that implementation. Otherwise, you can follow this basic pattern (code shown here is an implementation from ItemAutomationPeer).

protected override AutomationPeer GetLabeledByCore()
{
    if (base.Owner != null)
    { //this is the base call that makes sure AutomationProperties.LabeledBy
    // gets used if it is set on an instance
        return base.GetLabeledByCore();
    }
    AutomationPeer containerPeer = this.GetContainerPeer();
    if (containerPeer != null)
    { // this checks whether there is a container peer, and if so forwards
    //the call to that peer's version of the method
        return containerPeer.GetLabeledBy();
    }
    return null;
}

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.

Inheritance Hierarchy

共用方式為

FrameworkElementAutomationPeer Class

Inheritance Hierarchy

Syntax

Constructors

Properties

Methods

Remarks

FrameworkElementAutomationPeer *Core Method Implementations

Version Information

Silverlight

Silverlight for Windows Phone

Platforms

Thread Safety

See Also

Reference

Other Resources

Inheritance Hierarchy

其他資源