How can I determine if, given a window handle, the window handle is part of the Windows UI as opposed to an application?

After some digging, I found this question which references the "GetDesktopWindow()" and "GetShellWindow()" pinvoke functions. Using the GetShellWindow() api and it's pid, I was able to determine the process ID of the windows shell, and compare it to the process ID of the application I was currently moving. Finally, since file explorer windows are part of the explorer process, I checked to see if the window has "File Explorer" as it's title, or if any of it's parent windows do.

[DllImport("user32.dll", SetLastError = false)]
private static extern IntPtr GetShellWindow();

[DllImport("user32.dll", SetLastError = true)]
private static extern uint GetWindowThreadProcessId(IntPtr hWnd, out IntPtr lpdwProcessId);

public bool IsPartOfWindowsUI
{
  get
  {
      var desktopwindow = new WindowRef(GetShellWindow());
      return (desktopwindow.ThreadProcessID == ThreadProcessID &&
             //Check to see if title of this window or it's parents are
             //Basic file explorer windows 
             !TitleTree.Contains("File Explorer"));
  }
}