The EnumWindows function enumerates all top-level windows on the screen by passing the handle to each window, in turn, to an application-defined callback function. EnumWindows continues until the last top-level window is enumerated or the callback function returns FALSE.
Syntax
BOOL EnumWindows(
WNDENUMPROC lpEnumFunc,
LPARAM lParam
);
Parameters
- lpEnumFunc
-
[in] Pointer to an application-defined callback function. For more information, see EnumWindowsProc.
- lParam
-
[in] Specifies an application-defined value to be passed to the callback function.
Return Value
If the function succeeds, the return value is nonzero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.
If EnumWindowsProc returns zero, the return value is also zero. In this case, the callback function should call SetLastError to obtain a meaningful error code to be returned to the caller of EnumWindows.
Remarks
The EnumWindows function does not enumerate child windows, with the exception of a few top-level windows owned by the system that have the WS_CHILD style.
This function is more reliable than calling the GetWindow function in a loop. An application that calls GetWindow to perform this task risks being caught in an infinite loop or referencing a handle to a window that has been destroyed.
Function Information
| Minimum DLL Version | user32.dll |
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| Header | Declared in Winuser.h, include Windows.h |
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| Import library | User32.lib |
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| Minimum operating systems |
Windows 95, Windows NT 3.1 |
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| Unicode | Implemented as
Unicode version. |
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See Also
Windows Overview, EnumChildWindows, EnumWindowsProc, GetWindow