TaskbarItemInfo Class

Represents information about how the taskbar thumbnail is displayed.

Inheritance Hierarchy

System.Object
  System.Windows.Threading.DispatcherObject
    System.Windows.DependencyObject
      System.Windows.Freezable
        Microsoft.Windows.Shell.TaskbarItemInfo

Namespace:  Microsoft.Windows.Shell
Assembly:  Microsoft.Windows.Shell (in Microsoft.Windows.Shell.dll)

Syntax

'Declaration
Public NotInheritable Class TaskbarItemInfo _
    Inherits Freezable

public sealed class TaskbarItemInfo : Freezable

public ref class TaskbarItemInfo sealed : public Freezable

[<Sealed>]
type TaskbarItemInfo =  
    class
        inherit Freezable
    end

public final class TaskbarItemInfo extends Freezable

The TaskbarItemInfo type exposes the following members.

Constructors

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

Top

Properties

	Name	Description
	CanFreeze	Gets a value that indicates whether the object can be made unmodifiable. (Inherited from Freezable.)
	DependencyObjectType	Gets the DependencyObjectType that wraps the CLR type of this instance.  (Inherited from DependencyObject.)
	Description	Gets or sets the text for the taskbar item tooltip.
	Dispatcher	Gets the Dispatcher this DispatcherObject is associated with. (Inherited from DispatcherObject.)
	IsFrozen	Gets a value that indicates whether the object is currently modifiable. (Inherited from Freezable.)
	IsSealed	Gets a value that indicates whether this instance is currently sealed (read-only). (Inherited from DependencyObject.)
	Overlay	Gets or sets the image that is displayed over the program icon in the taskbar button.
	ProgressState	Gets or sets a value that indicates how the progress indicator is displayed in the taskbar button.
	ProgressValue	Gets or sets a value that indicates the fullness of the progress indicator in the taskbar button.
	ThumbButtonInfos	Gets or sets the collection of ThumbButtonInfo objects that are associated with the Window.
	ThumbnailClipMargin	Gets or sets a value that specifies the part of the application window's client area that is displayed in the taskbar thumbnail.

Top

Attached Properties

	Name	Description
	TaskbarItemInfo	Gets or sets a TaskbarItemInfo that is attached to a window.

Top

Methods

	Name	Description
	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.)
	Clone	Creates a modifiable clone of the Freezable, making deep copies of the object's values. When copying the object's dependency properties, this method copies expressions (which might no longer resolve) but not animations or their current values. (Inherited from Freezable.)
	CloneCore	Makes the instance a clone (deep copy) of the specified Freezable using base (non-animated) property values. (Inherited from Freezable.)
	CloneCurrentValue	Creates a modifiable clone (deep copy) of the Freezable using its current values. (Inherited from Freezable.)
	CloneCurrentValueCore	Makes the instance a modifiable clone (deep copy) of the specified Freezable using current property values. (Inherited from Freezable.)
	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.)
	CreateInstance	Initializes a new instance of the Freezable class. (Inherited from Freezable.)
	CreateInstanceCore	When implemented in a derived class, creates a new instance of the Freezable derived class. (Inherited from Freezable.)
	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.)
	Freeze	Makes the current object unmodifiable and sets its IsFrozen property to true. (Inherited from Freezable.)
	FreezeCore	Makes the Freezable object unmodifiable or tests whether it can be made unmodifiable. (Inherited from Freezable.)
	GetAsFrozen	Creates 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.)
	GetAsFrozenCore	Makes the instance a frozen clone of the specified Freezable using base (non-animated) property values. (Inherited from Freezable.)
	GetCurrentValueAsFrozen	Creates 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.)
	GetCurrentValueAsFrozenCore	Makes the current instance a frozen clone of the specified Freezable. If the object has animated dependency properties, their current animated values are copied. (Inherited from Freezable.)
	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.)
	GetTaskbarItemInfo	Gets the value of the TaskbarItemInfo attached property for an object.
	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.)
	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.)
	OnChanged	Called when the current Freezable object is modified. (Inherited from Freezable.)
	OnFreezablePropertyChanged(DependencyObject, DependencyObject)	Ensures that appropriate context pointers are established for a DependencyObjectType data member that has just been set. (Inherited from Freezable.)
	OnFreezablePropertyChanged(DependencyObject, DependencyObject, DependencyProperty)	This member supports the Windows Presentation Foundation (WPF) infrastructure and is not intended to be used directly from your code. (Inherited from Freezable.)
	OnPropertyChanged	Overrides the DependencyObject implementation of OnPropertyChanged to also invoke any Changed handlers in response to a changing dependency property of type Freezable. (Inherited from Freezable.)
	ReadLocalValue	Returns the local value of a dependency property, if it exists. (Inherited from DependencyObject.)
	ReadPreamble	Ensures that the Freezable is being accessed from a valid thread. Inheritors of Freezable must call this method at the beginning of any API that reads data members that are not dependency properties. (Inherited from Freezable.)
	SetTaskbarItemInfo	Sets the value of the TaskbarItemInfo attached property for an object.
	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.)
	WritePostscript	Raises the Changed event for the Freezable and invokes its OnChanged method. Classes that derive from Freezable should call this method at the end of any API that modifies class members that are not stored as dependency properties. (Inherited from Freezable.)
	WritePreamble	Verifies that the Freezable is not frozen and that it is being accessed from a valid threading context. Freezable inheritors should call this method at the beginning of any API that writes to data members that are not dependency properties. (Inherited from Freezable.)

Top

Events

	Name	Description
	Changed	Occurs when the Freezable or an object it contains is modified. (Inherited from Freezable.)

Top

Fields

	Name	Description
	DescriptionProperty	Identifies the Description dependency property.
	OverlayProperty	Identifies the Overlay dependency property.
	ProgressStateProperty	Identifies the ProgressState dependency property.
	ProgressValueProperty	Identifies the ProgressValue dependency property.
	TaskbarItemInfoProperty	Identifies the TaskbarItemInfo dependency property.
	ThumbButtonInfosProperty	Identifies the ThumbButtonInfos dependency property.
	ThumbnailClipMarginProperty	Identifies the ThumbnailClipMargin dependency property.

Top

Remarks

The TaskbarItemInfo class provides a managed wrapper for Windows 7 taskbar functionality. For more information about the Windows shell and native taskbar APIs, see Taskbar Extensions.

The Windows 7 taskbar provides enhanced functionality that enables you to use the taskbar item to communicate status to a user and expose common tasks when the window is minimized or hidden. The functionality that is exposed by the TaskbarItemInfo class is unavailable in versions of Windows earlier than Windows 7. Applications that use the TaskbarItemInfo class can still run in earlier versions of Windows; however, these taskbar enhancements are unavailable in the earlier versions. 

In Windows 7, some taskbar functionality might be unavailable, depending on the user's settings. For example, taskbar functionality is unavailable if Windows Aero is disabled or if the application is started with elevated permissions. Your application should provide other ways to interact with the user that do not depend on the enhanced taskbar functionality in Windows 7.

Program icons in the notification area, which is at the far right of the taskbar, are typically used to communicate application status to a user. By default, the Windows 7 taskbar hides program icons in the notification area. However, you can set the Overlay property to add an image to the taskbar button to communicate status, such as online status in a messaging application. The overlay image lets users see the application status even if they cannot see the program icon in the notification area. You can also display the progress of running tasks in the taskbar button by setting the ProgressState and ProgressValue properties.

The Windows 7 taskbar displays a thumbnail of the application when you move the mouse pointer over the taskbar button. By default the whole application window is shown. You can specify a particular part of the window to display in the thumbnail by setting the ThumbnailClipMargin property. You can also specify a Description that is displayed in a tooltip above the taskbar thumbnail. The tooltip is displayed even when the thumbnail cannot be seen because of user settings. 

You can add buttons to the taskbar thumbnail to provide access to common tasks without switching to the application window. For example, Window Media Player provides Play, Pause, Forward, and Back buttons that let you control media playback from the taskbar thumbnail when the application is minimized. Buttons in the taskbar thumbnail are represented by ThumbButtonInfo objects and are contained in the ThumbButtonInfos collection.

The following illustration shows the enhanced features of the Windows 7 taskbar.

Windows Taskbar Enhanced Features

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.

See Also

Reference

Microsoft.Windows.Shell Namespace