GetClassInfoExA function (winuser.h)
Retrieves information about a window class, including a handle to the small icon associated with the window class. The GetClassInfo function does not retrieve a handle to the small icon.
Syntax
BOOL GetClassInfoExA(
[in, optional] HINSTANCE hInstance,
[in] LPCSTR lpszClass,
[out] LPWNDCLASSEXA lpwcx
);
Parameters
[in, optional] hInstance
Type: HINSTANCE
A handle to the instance of the application that created the class. To retrieve information about classes defined by the system (such as buttons or list boxes), set this parameter to NULL.
[in] lpszClass
Type: LPCTSTR
The class name. The name must be that of a preregistered class or a class registered by a previous call to the RegisterClass or RegisterClassEx function. Alternatively, this parameter can be a class atom created by a previous call to RegisterClass or RegisterClassEx. The atom must be in the low-order word of lpszClass; the high-order word must be zero.
[out] lpwcx
Type: LPWNDCLASSEX
A pointer to a WNDCLASSEX structure that receives the information about the class.
Return value
Type: BOOL
If the function finds a matching class and successfully copies the data, the return value is nonzero.
If the function does not find a matching class and successfully copy the data, the return value is zero. To get extended error information, call GetLastError.
Remarks
Class atoms are created using the RegisterClass or RegisterClassEx function, not the GlobalAddAtom function.
Note
The winuser.h header defines GetClassInfoEx as an alias that automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that is not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows 2000 Professional [desktop apps only] |
| Minimum supported server | Windows 2000 Server [desktop apps only] |
| Target Platform | Windows |
| Header | winuser.h (include Windows.h) |
| Library | User32.lib |
| DLL | User32.dll |
| API set | ext-ms-win-ntuser-windowclass-l1-1-0 (introduced in Windows 8) |
See also
Conceptual
Reference