FindWindowA function (winuser.h)
Retrieves a handle to the top-level window whose class name and window name match the specified strings. This function does not search child windows. This function does not perform a case-sensitive search.
To search child windows, beginning with a specified child window, use the FindWindowEx function.
Syntax
HWND FindWindowA(
[in, optional] LPCSTR lpClassName,
[in, optional] LPCSTR lpWindowName
);
Parameters
[in, optional] lpClassName
Type: LPCTSTR
The class name or a class atom created by a previous call to the RegisterClass or RegisterClassEx function. The atom must be in the low-order word of lpClassName; the high-order word must be zero.
If lpClassName points to a string, it specifies the window class name. The class name can be any name registered with RegisterClass or RegisterClassEx, or any of the predefined control-class names.
If lpClassName is NULL, it finds any window whose title matches the lpWindowName parameter.
[in, optional] lpWindowName
Type: LPCTSTR
The window name (the window's title). If this parameter is NULL, all window names match.
Return value
Type: HWND
If the function succeeds, the return value is a handle to the window that has the specified class name and window name.
If the function fails, the return value is NULL. This function does not modify the last error value.
Remarks
If the lpWindowName parameter is not NULL, FindWindow calls the GetWindowText function to retrieve the window name for comparison. For a description of a potential problem that can arise, see the Remarks for GetWindowText.
Examples
For an example, see Retrieving the Number of Mouse Wheel Scroll Lines.
Note
The winuser.h header defines FindWindow 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-window-l1-1-0 (introduced in Windows 8) |
See also
Conceptual
Reference