LONG GetClassLong(hWnd,nIndex)
This function retrieves the long value specified by the nIndex parameter from 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 value to be retrieved. It can also be the following value: | ||
| Value | Meaning | ||
| GCL_WNDPROC | Retrieves a long pointer to the window function. | ||
The return value specifies the value retrieved from the WNDCLASS structure.
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. The first four-byte value in the extra space is at offset zero, the next four-byte value is at offset 4, and so on.