The GetClassWord function retrieves the 16-bit (word) value at the specified offset into the extra class memory for the window class to which the specified window belongs.
Other than GCW_ATOM and GCW_HICONSM, the GCW_ values are obsolete in the Win32 API. You must use the GetClassLong function to retrieve the class values of a window.
WORD GetClassWord(
| HWND hWnd, | // handle of window |
| int nIndex | // offset of value to retrieve |
| ); |
Parameters
hWnd
Identifies the window and, indirectly, the class to which the window belongs.
nIndex
Specifies the zero-based byte offset of the value to be retrieved. Valid values are in the range zero through the number of bytes of class memory, minus two; for example, if you specified 10 or more bytes of extra class memory, a value of eight would be an index to the fifth 16-bit integer. There is an additional valid value:
| Value | Action |
| GCW_ATOM | Retrieves an ATOM value that uniquely identifies the window class. This is the same atom that the RegisterClass function returns. |
| GCW_HICONSM | Retrieves the handle of the small icon associated with the window. |
Return Values
If the function succeeds, the return value is the requested 16-bit value.
If the function fails, the return value is otherwise, it is zero. To get extended error information, call GetLastError.
Remarks
Reserve extra class memory by specifying a nonzero value in the cbClsExtra member of the WNDCLASS structure used with the RegisterClass function.
See Also
GetClassLong, RegisterClass, SetClassLong, SetClassWord, WNDCLASS