Method dialog.SetIcon(+ 1 overload) Overload Sets common icon. Or custom icon from app resources. public void SetIcon(DIcon icon) Parameters icon (DIcon) Overload(top) Sets custom icon. public void SetIcon(object icon) Parameters icon (object) Icon of size 32 or 16 (or more if high DPI). Can be icon, Icon, IntPtr (native icon handle), Bitmap.