(integer) Another set of flags of the same type as winstyle. These correspond to the “dwStyleEx” parameter in the WIN32 API CreateWindowsEx() function.

For what it’s worth, the addition of this second set of flags is what distinguishes CreateWindowEx() from the earlier CreateWindow(); even Microsoft is guilty of not seeing far enough into the future to prevent having to add more parameters to functions over time. We have the advantage, though, of being able to use variable length argument lists, so at least we do not have to create a whole new “Ex” version of a function just to add another parameter.

Symbol	Value	Description
WS_EX_DLGMODALFRAME	&h00000001
WS_EX_NOPARENTNOTIFY	&h00000004
WS_EX_TOPMOST	&h00000008
WS_EX_ACCEPTFILES	&h00000010
WS_EX_TRANSPARENT	&h00000020
WS_EX_TOOLWINDOW	&h00000080
WS_EX_WINDOWEDGE	&h00000100
WS_EX_CLIENTEDGE	&h00000200
WS_EX_CONTEXTHELP	&h00000400