TaskbarItemInfo Class

.NET Framework (current version)
 

Represents information about how the taskbar thumbnail is displayed.

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

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

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

NameDescription
System_CAPS_pubmethodTaskbarItemInfo()

Initializes a new instance of the TaskbarItemInfo class.

NameDescription
System_CAPS_pubpropertyCanFreeze

Gets a value that indicates whether the object can be made unmodifiable. (Inherited from Freezable.)

System_CAPS_pubpropertyDependencyObjectType

Gets the DependencyObjectType that wraps the CLR type of this instance. (Inherited from DependencyObject.)

System_CAPS_pubpropertyDescription

Gets or sets the text for the taskbar item tooltip.

System_CAPS_pubpropertyDispatcher

Gets the Dispatcher this DispatcherObject is associated with. (Inherited from DispatcherObject.)

System_CAPS_pubpropertyIsFrozen

Gets a value that indicates whether the object is currently modifiable. (Inherited from Freezable.)

System_CAPS_pubpropertyIsSealed

Gets a value that indicates whether this instance is currently sealed (read-only).(Inherited from DependencyObject.)

System_CAPS_pubpropertyOverlay

Gets or sets the image that is displayed over the program icon in the taskbar button.

System_CAPS_pubpropertyProgressState

Gets or sets a value that indicates how the progress indicator is displayed in the taskbar button.

System_CAPS_pubpropertyProgressValue

Gets or sets a value that indicates the fullness of the progress indicator in the taskbar button.

System_CAPS_pubpropertyThumbButtonInfos

Gets or sets the collection of ThumbButtonInfo objects that are associated with the Window.

System_CAPS_pubpropertyThumbnailClipMargin

Gets or sets a value that specifies the part of the application window's client area that is displayed in the taskbar thumbnail.

NameDescription
System_CAPS_pubmethodCheckAccess()

Determines whether the calling thread has access to this DispatcherObject.(Inherited from DispatcherObject.)

System_CAPS_pubmethodClearValue(DependencyProperty)

Clears the local value of a property. The property to be cleared is specified by a DependencyProperty identifier. (Inherited from DependencyObject.)

System_CAPS_pubmethodClearValue(DependencyPropertyKey)

Clears the local value of a read-only property. The property to be cleared is specified by a DependencyPropertyKey. (Inherited from DependencyObject.)

System_CAPS_pubmethodClone()

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.)

System_CAPS_pubmethodCloneCurrentValue()

Creates a modifiable clone (deep copy) of the Freezable using its current values.(Inherited from Freezable.)

System_CAPS_pubmethodCoerceValue(DependencyProperty)

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.)

System_CAPS_pubmethodEquals(Object)

Determines whether a provided DependencyObject is equivalent to the current DependencyObject.(Inherited from DependencyObject.)

System_CAPS_pubmethodFreeze()

Makes the current object unmodifiable and sets its IsFrozen property to true. (Inherited from Freezable.)

System_CAPS_pubmethodGetAsFrozen()

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.)

System_CAPS_pubmethodGetCurrentValueAsFrozen()

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.)

System_CAPS_pubmethodGetHashCode()

Gets a hash code for this DependencyObject.(Inherited from DependencyObject.)

System_CAPS_pubmethodGetLocalValueEnumerator()

Creates a specialized enumerator for determining which dependency properties have locally set values on this DependencyObject. (Inherited from DependencyObject.)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethodGetValue(DependencyProperty)

Returns the current effective value of a dependency property on this instance of a DependencyObject. (Inherited from DependencyObject.)

System_CAPS_pubmethodInvalidateProperty(DependencyProperty)

Re-evaluates the effective value for the specified dependency property(Inherited from DependencyObject.)

System_CAPS_pubmethodReadLocalValue(DependencyProperty)

Returns the local value of a dependency property, if it exists. (Inherited from DependencyObject.)

System_CAPS_pubmethodSetCurrentValue(DependencyProperty, Object)

Sets the value of a dependency property without changing its value source. (Inherited from DependencyObject.)

System_CAPS_pubmethodSetValue(DependencyProperty, Object)

Sets the local value of a dependency property, specified by its dependency property identifier. (Inherited from DependencyObject.)

System_CAPS_pubmethodSetValue(DependencyPropertyKey, Object)

Sets the local value of a read-only dependency property, specified by the DependencyPropertyKey identifier of the dependency property. (Inherited from DependencyObject.)

System_CAPS_protmethodShouldSerializeProperty(DependencyProperty)

Returns a value that indicates whether serialization processes should serialize the value for the provided dependency property.(Inherited from DependencyObject.)

System_CAPS_pubmethodToString()

Returns a string that represents the current object.(Inherited from Object.)

System_CAPS_pubmethodVerifyAccess()

Enforces that the calling thread has access to this DispatcherObject.(Inherited from DispatcherObject.)

NameDescription
System_CAPS_pubfieldSystem_CAPS_staticDescriptionProperty

Identifies the Description dependency property.

System_CAPS_pubfieldSystem_CAPS_staticOverlayProperty

Identifies the Overlay dependency property.

System_CAPS_pubfieldSystem_CAPS_staticProgressStateProperty

Identifies the ProgressState dependency property.

System_CAPS_pubfieldSystem_CAPS_staticProgressValueProperty

Identifies the ProgressValue dependency property.

System_CAPS_pubfieldSystem_CAPS_staticThumbButtonInfosProperty

Identifies the ThumbButtonInfos dependency property.

System_CAPS_pubfieldSystem_CAPS_staticThumbnailClipMarginProperty

Identifies the ThumbnailClipMargin dependency property.

NameDescription
System_CAPS_pubeventChanged

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

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.

Taskbar Item Info Sample

Windows Taskbar Enhanced Features

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
Available since 4.0

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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