GetClassWord
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