Windows API - Set the icon of a window created with P/Invoke

This actually turned out to be very easy. Just load the icon as you would in .net.

var icon = new Icon(GetResourceStream("Cards.ico"));

GetResourceStream is a custom method of mine to load the icon file from the embedded resources.

To create the window, you already defined a window class struct somewhere.

var windowClass = new WindowClassEx();

All you have to do, is pass the icon's internal handle to this structure.

windowClass.Icon = icon.Handle;

And make sure the icon object is not destroyed while the window is open.

Windows will look for a small icon for the title bar in Icon when IconSmall is not set.