GetClassNameW function (winuser.h)

Article
02/09/2023

Retrieves the name of the class to which the specified window belongs.

Syntax

int GetClassNameW(
  [in]  HWND   hWnd,
  [out] LPWSTR lpClassName,
  [in]  int    nMaxCount
);

Parameters

[in] hWnd

Type: HWND

A handle to the window and, indirectly, the class to which the window belongs.

[out] lpClassName

Type: LPTSTR

The class name string.

[in] nMaxCount

Type: int

The length of the lpClassName buffer, in characters. The buffer must be large enough to include the terminating null character; otherwise, the class name string is truncated to nMaxCount-1 characters.

Return value

Type: int

If the function succeeds, the return value is the number of characters copied to the buffer, not including the terminating null character.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Note

The winuser.h header defines GetClassName as an alias which 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 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)