How can I have a (semi) transparent background in GTK Sharp?

How can I have a (semi) transparent backg开发者_开发百科round in GTK Sharp?

In C it's gtk_window_set_opacity(window, 0.5); I don't know if this function is wrapped in Gtk#.

Since Gtk version 3.8 (released in 2013) you shall use gtk_widget_set_opacity() method instead. They have the same prototype (ofc GtkWidget pointer instead of GtkWindow).

While on Windows it shall always work, on X11 this has any effect only on X screens with a compositing manager running.