In App.xaml.cs you can override a method called OnWindowCreated(...) . This will be triggered as soon as you have a new βchromeβ for the game ... and, unfortunately, there is nothing there that would allow you to change the opacity of the container.
You can also access this anytime after the application starts using Window.Current , which will give you the currently active window. Again ... there is nothing to resolve the opacity.
Perhaps Microsoft will add this option in the future. So leave this question open for future answers :)
Laith source share