WORD SetClassWord(hWnd,nIndex,wNewWord)
This function replaces the word specified by the nIndex parameter in the WNDCLASS structure of the window specified by the hWnd parameter.
| Parameter | Type/Description |
| hWnd | HWND Identifies the window. | ||
| nIndex | int Specifies the byte offset of the word to be changed. It can also be one of the following values: | ||
| Value | Meaning | ||
| GCW_CBCLSEXTRA | Sets two new bytes of additional window-class data. | ||
| GCW_CBWNDEXTRA | Sets two new bytes of additional window-class data. | ||
| GCW_HBRBACKGROUND | Sets a new handle to a background brush. | ||
| GCW_HCURSOR | Sets a new handle to a cursor. | ||
| GCW_HICON | Sets a new handle to an icon. | ||
| GCW_STYLE | Sets a new style bit for the window class. | ||
| wNewWord | WORD Specifies the replacement value. | ||
The return value specifies the previous value of the specified word.
The SetClassWord function should be used with care. For example, it is possible to change the background color for a class by using SetClassWord, but this change does not cause all windows belonging to the class to be repainted immediately.
To access any extra four-byte values allocated when the window-class structure was created, use a positive byte offset as the index specified by the nIndex parameter, starting at zero for the first four-byte value in the extra space, 4 for the next four-byte value and so on.