wShowWindow

wShowWindow is a term used in Win32 programming to refer to the wParam parameter of the WM_SHOWWINDOW message. This message is sent to a window when its visibility changes, such as when it is about to be shown or hidden.

In WM_SHOWWINDOW, the wParam parameter indicates the new visibility state as a BOOL value: nonzero (TRUE) means the window is being shown, while zero (FALSE) means the window is being hidden. The lParam parameter is not used. The message is delivered to a window procedure after a visibility change has been requested, typically through the ShowWindow or ShowWindowAsync functions.

Handling WM_SHOWWINDOW allows an application to respond to visibility changes. Typical actions include updating UI elements, starting or stopping animations, loading resources when the window becomes visible, or releasing resources when it is hidden. The handling is performed inside the window procedure, usually by checking the wParam value to distinguish between show and hide events.

Relation to ShowWindow: ShowWindow is a function that requests a change in a window’s visibility state, while WM_SHOWWINDOW is the notification sent to the window when that state changes. This distinction is important for understanding the flow of visibility events in a Win32 application.

See also: WM_SHOWWINDOW, ShowWindow, ShowWindowAsync.