I’m having problems with a window in WPF

if I set :

ResizeMode="NoResize" 
WindowStyle="None"

the window will look flat and without rounded borders and shadow beneath.

Is the a way to solve this? without using a border with effect DropShadow

I’ve tried this solution: dropshadow-for-wpf-borderless-window , but the window will refuse to render the content and just display a white rectangle with the appropriate shadow and rounded borders.

Thanks in advance

dropshadow-for-wpf-borderless-window