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TaskbarItemInfo Class

Represents information about how the taskbar thumbnail is displayed.

Namespace:  System.Windows.Shell
Assembly:  PresentationFramework (in PresentationFramework.dll)
XMLNS for XAML: Not mapped to an xmlns.

public ref class TaskbarItemInfo sealed : public Freezable
<TaskbarItemInfo .../>

The TaskbarItemInfo type exposes the following members.

  NameDescription
Public methodTaskbarItemInfoInitializes a new instance of the TaskbarItemInfo class.
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  NameDescription
Public propertyCanFreezeGets a value that indicates whether the object can be made unmodifiable. (Inherited from Freezable.)
Public propertyDependencyObjectTypeGets the DependencyObjectType that wraps the CLR type of this instance.  (Inherited from DependencyObject.)
Public propertyDescriptionGets or sets the text for the taskbar item tooltip.
Public propertyDispatcherGets the Dispatcher this DispatcherObject is associated with. (Inherited from DispatcherObject.)
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 propertyOverlayGets or sets the image that is displayed over the program icon in the taskbar button.
Public propertyProgressStateGets or sets a value that indicates how the progress indicator is displayed in the taskbar button.
Public propertyProgressValueGets or sets a value that indicates the fullness of the progress indicator in the taskbar button.
Public propertyThumbButtonInfosGets or sets the collection of ThumbButtonInfo objects that are associated with the Window.
Public propertyThumbnailClipMarginGets or sets a value that specifies the part of the application window's client area that is displayed in the taskbar thumbnail.
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  NameDescription
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 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.)
Public methodCloneCurrentValueCreates a modifiable clone (deep copy) of the Freezable using its current values. (Inherited from Freezable.)
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 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 methodToStringReturns a string that represents the current object. (Inherited from Object.)
Public methodVerifyAccessEnforces that the calling thread has access to this DispatcherObject. (Inherited from DispatcherObject.)
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  NameDescription
Public eventChangedOccurs when the Freezable or an object it contains is modified. (Inherited from Freezable.)
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  NameDescription
Public fieldStatic memberDescriptionPropertyIdentifies the Description dependency property.
Public fieldStatic memberOverlayPropertyIdentifies the Overlay dependency property.
Public fieldStatic memberProgressStatePropertyIdentifies the ProgressState dependency property.
Public fieldStatic memberProgressValuePropertyIdentifies the ProgressValue dependency property.
Public fieldStatic memberThumbButtonInfosPropertyIdentifies the ThumbButtonInfos dependency property.
Public fieldStatic memberThumbnailClipMarginPropertyIdentifies the ThumbnailClipMargin dependency property.
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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 ExtensionsTaskbarItemInfo is exposed as the Window::TaskbarItemInfo dependency property on a Window.

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

Taskbar Item Info Sample

The following example shows how to create a TaskbarItemInfo in markup. The TaskbarItemInfo contains a collection of ThumbButtonInfo objects that provide access to the Play and Stop commands from the taskbar item.

<Window.TaskbarItemInfo>
    <TaskbarItemInfo x:Name="taskBarItemInfo1" 
                     Overlay="{StaticResource ResourceKey=StopImage}"
                     ThumbnailClipMargin="80,0,80,140"
                     Description="Taskbar Item Info Sample">
        <TaskbarItemInfo.ThumbButtonInfos>
            <ThumbButtonInfoCollection>
                <ThumbButtonInfo
                    DismissWhenClicked="False"
                    Command="MediaCommands.Play"
                    CommandTarget="{Binding ElementName=btnPlay}"
                    Description="Play"
                    ImageSource="{StaticResource ResourceKey=PlayImage}"/>
                <ThumbButtonInfo
                    DismissWhenClicked="True"
                    Command="MediaCommands.Stop"
                    CommandTarget="{Binding ElementName=btnStop}"
                    Description="Stop"
                    ImageSource="{StaticResource ResourceKey=StopImage}"/>
            </ThumbButtonInfoCollection>
        </TaskbarItemInfo.ThumbButtonInfos>
    </TaskbarItemInfo>
</Window.TaskbarItemInfo>

The following markup and code shows the previous example in its full context. The application uses a BackgroundWorker to count from 0 to 100 and displays its progress in the user interface. The task can be started and stopped from the taskbar preview. The progress is displayed in the taskbar button.

<Window x:Class="Shell_TaskbarItemSample.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="300" Width="300">
    <Window.Resources>
        <DrawingImage x:Key="PlayImage">
            <DrawingImage.Drawing>
                <DrawingGroup>
                    <DrawingGroup.Children>
                        <GeometryDrawing Brush="Green" Geometry="F1 M 50,25L 0,0L 0,50L 50,25 Z "/>
                    </DrawingGroup.Children>
                </DrawingGroup>
            </DrawingImage.Drawing>
        </DrawingImage>
        <DrawingImage x:Key="StopImage">
            <DrawingImage.Drawing>
                <DrawingGroup>
                    <DrawingGroup.Children>
                        <GeometryDrawing Brush="Gray" Geometry="F1 M 0,0L 50,0L 50,50L 0,50L 0,0 Z "/>
                    </DrawingGroup.Children>
                </DrawingGroup>
            </DrawingImage.Drawing>
        </DrawingImage>
    </Window.Resources>
    <Window.CommandBindings>
        <CommandBinding Command="MediaCommands.Play"
                  Executed="StartCommand_Executed"
                  CanExecute="StartCommand_CanExecute"/>
        <CommandBinding Command="MediaCommands.Stop"
                  Executed="StopCommand_Executed"
                  CanExecute="StopCommand_CanExecute"/>
    </Window.CommandBindings>
    <Window.TaskbarItemInfo>
        <TaskbarItemInfo x:Name="taskBarItemInfo1" 
                         Overlay="{StaticResource ResourceKey=StopImage}"
                         ThumbnailClipMargin="80,0,80,140"
                         Description="Taskbar Item Info Sample">
            <TaskbarItemInfo.ThumbButtonInfos>
                <ThumbButtonInfoCollection>
                    <ThumbButtonInfo
                        DismissWhenClicked="False"
                        Command="MediaCommands.Play"
                        CommandTarget="{Binding ElementName=btnPlay}"
                        Description="Play"
                        ImageSource="{StaticResource ResourceKey=PlayImage}"/>
                    <ThumbButtonInfo
                        DismissWhenClicked="True"
                        Command="MediaCommands.Stop"
                        CommandTarget="{Binding ElementName=btnStop}"
                        Description="Stop"
                        ImageSource="{StaticResource ResourceKey=StopImage}"/>
                </ThumbButtonInfoCollection>
            </TaskbarItemInfo.ThumbButtonInfos>
        </TaskbarItemInfo>
    </Window.TaskbarItemInfo>

    <Grid>
        <StackPanel>
            <TextBlock x:Name="tbCount" FontSize="72" HorizontalAlignment="Center"/>
            <StackPanel Orientation="Horizontal">
                <Button x:Name="btnPlay" Content="Play" Command="MediaCommands.Play" />
                <Button x:Name="btnStop" Content="Stop" Command="MediaCommands.Stop" />
            </StackPanel>    
        </StackPanel>
    </Grid>
</Window>
No code example is currently available or this language may not be supported.

.NET Framework

Supported in: 4.5, 4

.NET Framework Client Profile

Supported in: 4

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.
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