Win32 API Windows Subclassing
Introduction
Window subclassing is a way to hook up into standard window procedure and to modify or extend its default behavior. An application subclasses a window by replacing the the window's original window procedure with a new window procedure. This new window procedure receives any messages sent or posted to the window.
Syntax
- BOOL SetWindowSubclass(HWND hWnd, SUBCLASSPROC SubclassProc, UINT_PTR SubclassId, DWORD_PTR RefData);
- BOOL RemoveWindowSubclass(HWND hWnd, SUBCLASSPROC SubclassProc, UINT_PTR SubclassId);
- BOOL GetWindowSubclass(HWND hWnd, SUBCLASSPROC SubclassProc, UINT_PTR SubclassId, DORD_PTR* RefData);
- LRESULT DefSubclassProc(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam);
Parameters
| Parameter | Detail |
|---|---|
| hWnd | The handle of the window to subclass. |
| SubclassProc | The subclass callback procedure. |
| SubclassId | User specified ID to identify the subclass, together with the subclass procedure uniquely identifies a subclass. It can simply be an arbitrary consecutive number. |
| RefData | User specified data. The meaning is determined by the application. It is passed to the subclass callback in unmodified way. It could be an object pointer to a class instance for example. |
Remarks
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