Showing progress in the taskbar with a Telerik RadWindow

Showing the progress of your application gives the user a better experience. They can continue with other tasks and still see where your app is up to.

Adding this for a regular WPF Window is quite simple, you can create a TaskbarItemInfo in markup:

<Window.TaskbarItemInfo>
    <TaskbarItemInfo x:Name="taskBarItemInfo" />
</Window.TaskbarItemInfo>

The ProgressValue takes a double between 0 – 1 where 0 has no green bar and 1 is a full bar.
The ProgressState takes an enum of TaskbarItemProgressState which can be:

So setting the ProgressState to normal, and the ProgressValue to .50

taskbarItemInfo.ProgressState = TaskbarItemProgressState.Normal;
taskbarItemInfo.ProgressValue = .5;

Will look like this:

We can then set the ProgressValue to update according to the task we’re processing and set the ProgressState back to none when done.

The RadWindow though does not expose a TaskbarItemInfo property. It is primarily a child window, and whilst it can used as a main Window it does not have all the properties a regular WPF Window has.
To get around this issue we need to tap into the parent of the RadWindow, this is a regular WPF Window. Then we can set the TaskbarItemInfo up on that.

private void ShowProgressInTaskbar() {
  Dispatcher.Invoke(() => {
    Window window = this.ParentOfType<Window>();
    if (window != null) {
      window.TaskbarItemInfo = new() {
        ProgressState = TaskbarItemProgressState.Normal,
        ProgressValue = .5
      };
    }
  });
}

We need to invoke the dispatcher since the code is running on a different thread than the UI. If your setting the ProgressValue elsewhere then that will also need to be wrapped in a Dispatcher.Invoke:

while ((read = input.Read(buffer, 0, buffer.Length)) > 0) {
  output.Write(buffer, 0, read);
  totalRead += read;
  int megabytesRead = totalRead / 1024 / 1024;
  ProgressValue = megabytesRead * 100 / megabytesTotal;
  BusyContent = title + Environment.NewLine + $"Saving {megabytesRead} MB / {megabytesTotal} MB ...";
  Dispatcher.Invoke(() => {
    Window.TaskbarItemInfo.ProgressValue = Math.Round(ProgressValue / 100d, 2);
  });
}