[WPF][C#] Window not maximized when running on Administrator?

I have WPF application with a child window (Test) and it should be run on Administrator mode. So run your Visual Studio as administrator. And the child window will be triggered using the below code.

Test win = new Test();
win.Owner = this;
win.ShowDialog();

When minimizing the child window, the parent window is not minimized and also the child window was not minimized completely because I have used ShowInTaskbar as false for child window. Hence I have used the below code in child window.

protected override void OnStateChanged(EventArgs e)
{
   base.OnStateChanged(e);
   if (this.Owner != null && this.WindowState == WindowState.Minimized)
   {
       this.Owner.WindowState = WindowState.Minimized;
   }
}