How to set StartUri in WPF

We can easily set the start window of a WPF application by setting the StartupUri property of the Application node in the App.xaml to the window xaml file name, such as "Window1.xaml". But if the Window1.xmal is placed in another folder, what can we do?

We only need to add the directory path before the window xaml file name, such as "Palyer/MyPlayerWindow.xaml" or "Palyer\MyPlayerWindow.xaml".