Class

RadTaskbarButton

int

For more information, see: https://learn.microsoft.com/en-us/windows/win32/api/shobjidl_core/nf-shobjidl_core-itaskbarlist3-thumbbaraddbuttons

Control

When set, the thumbnail preview will be clipped to show only the area occupied by the specified control. This provides a convenient way to focus the thumbnail on important content without manually calculating coordinates.

Setting this property will automatically reset the ClipRectangle property to Empty. Set to null to show the entire form in the thumbnail.

Rectangle

When set, only the specified rectangular area of the form will be visible in the taskbar thumbnail preview. This is useful for focusing the preview on a specific area of the application, such as the main content area.

Setting this property will automatically reset the ClipControl property to null. Set to Empty to show the entire form in the thumbnail.

Bitmap

The overlay icon appears as a small badge in the bottom-right corner of the taskbar button. It is typically used to indicate application state such as new messages, alerts, or status information. Set to null to remove the overlay icon.

Form

The form must have ShowInTaskbar set to true for taskbar features to work. Taskbar functionality is only available on Windows 7 and higher operating systems. Setting this property will automatically initialize the necessary Windows API components if the requirements are met.

int

The progress percentage is only visible when ProgressState is set to Normal, Error, or Paused. Values are automatically clamped to the range 0-100. The progress bar appears as an overlay on the taskbar button.

TaskbarProgressState

The progress state controls the visual appearance of the progress bar overlay on the taskbar button. Different states provide different visual feedback: Normal (green), Error (red), Paused (yellow), Indeterminate (pulsing animation), or NoProgress (hidden).

ISite

When the component is used in a designer, this property automatically sets the OwnerForm to the root component if it is a form.

ObservableCollection<RadThumbnailButton>

The thumbnail buttons represent a toolbar that appears below the application preview in the taskbar flyout. A maximum of MaxThumbnailButtonsCount buttons can be added to the collection.

If buttons are created at design time or before the Shown event, the toolbar will be automatically created and populated. After the Shown event, you must explicitly call AddThumbnailButtons() to create the toolbar.

Once a toolbar has been added, buttons can only be modified through UpdateThumbnailButtons(). Individual buttons cannot be added or removed, but they can be shown and hidden as needed. The toolbar itself cannot be removed without recreating the window.

ImageList

This image list provides the icons for the thumbnail toolbar buttons. The ImageKey or ImageIndex properties of individual buttons reference images in this collection. Changes to this property automatically update all existing thumbnail buttons.

string

This tooltip is separate from the standard Windows tooltip that shows the window title. It can be used to provide additional context or status information about the application. Set to null or empty string to use the default Windows behavior.

Once this method is executed and a toolbar has been created, buttons can only be modified through UpdateThumbnailButtons(). Individual buttons cannot be added or removed after the toolbar is created, but they can be shown and hidden as needed. The toolbar itself cannot be removed without recreating the window.

If the toolbar has already been created, this method will call UpdateThumbnailButtons() instead. A maximum of MaxThumbnailButtonsCount buttons can be added.

TaskbarFilterWindow

A new TaskbarFilterWindow instance.

This method is called internally to create the message filter window that processes thumbnail button click messages. Derived classes can override this method to provide custom filter window implementations.

disposing

bool

True to release both managed and unmanaged resources; false to release only unmanaged resources.

count

int

The number of times the taskbar button will flash. Use MaxValue for infinite flashing until StopFlash() is called.

timeout

int

The rate at which the window flashes in milliseconds. Use 0 for the default cursor blink rate.

Flashing is typically used to inform the user that the window requires attention but does not currently have keyboard focus. When a window flashes, it appears to change from inactive to active status - an inactive caption bar changes to active and vice versa.

The flashing continues for the specified count or until StopFlash() is called.

count

int

The maximum number of times the taskbar button will flash. Use MaxValue for infinite flashing until the application is focused or StopFlash() is called.

timeout

int

The rate at which the window flashes in milliseconds. Use 0 for the default cursor blink rate.

This method will not begin flashing if the window is currently active. The flashing automatically stops when the user activates the window.

This is particularly useful for applications that need to notify users of important events while respecting user focus.

button

RadThumbnailButton

The thumbnail button that has been modified and needs to be updated.

This method is called automatically when thumbnail button properties change, but can be called manually if needed. It updates only the specified button rather than all buttons for better performance.

button

RadThumbnailButton

The thumbnail button that was clicked.

This method can be overridden in derived classes to provide custom handling of thumbnail button clicks before or instead of raising the event.

image

Bitmap

The bitmap image to display as an overlay, or null to remove the overlay.

accessibilityText

string

Optional accessibility text that describes the overlay icon for screen readers.

The overlay icon appears as a small badge in the bottom-right corner of the taskbar button. Providing accessibility text improves the experience for users with screen readers.

state

TaskbarProgressState

The progress state to apply to the taskbar button.

The progress state controls how the progress overlay is displayed: Normal (green), Error (red), Paused (yellow), Indeterminate (pulsing animation), or NoProgress (hidden).

percent

int

The progress value as a percentage from 0 to 100.

The progress value is only visible when the progress state is Normal, Error, or Paused. Values outside the 0-100 range will be clamped automatically.

completed

int

The number of completed units.

total

int

The total number of units.

This overload allows setting progress using absolute values rather than percentages. The progress percentage will be calculated as (completed / total) * 100.

clipControl

Control

The control whose bounds will define the visible thumbnail area, or null to show the entire form.

This method provides a convenient way to focus the thumbnail preview on a specific control without manually calculating the control's screen coordinates.

clipRect

Rectangle

The rectangle defining the visible thumbnail area, or Empty to show the entire form.

The rectangle coordinates should be relative to the client area of the owner form. This method allows precise control over which part of the form appears in the thumbnail preview.

thumbnailTooltip

string

The tooltip text to display, or null to use the default Windows behavior.

This tooltip is separate from the standard Windows tooltip and can provide additional context or status information about the application state.

This method can be called to stop flashing that was initiated by Flash(int, int) or FlashUntilActive(int, int). It is safe to call this method even if the window is not currently flashing.

This method is typically called automatically when the owner form is shown, but can be called manually to refresh all taskbar features after making multiple changes.

After a thumbnail toolbar has been created with AddThumbnailButtons(), this is the only way to modify button properties. Individual buttons cannot be added or removed, but their properties (such as visibility, enabled state, and icons) can be updated.

This method updates all buttons in the toolbar. For updating a single button, use OnThumbnailButtonChanged(RadThumbnailButton) which is more efficient.

ThumbnailButtonEventHandler

This event is raised after the individual button's internal click handling is processed. The event provides access to the clicked button through the ThumbnailButtonEventArgs parameter.