EnumWindows function

https://msdn.microsoft.com/en-us/library/windows/desktop/ms633497(v=vs.85).aspx

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.

C++的代码

BOOL WINAPI EnumWindows(
  _In_ WNDENUMPROC lpEnumFunc,
  _In_ LPARAM      lParam
);

Parameters

lpEnumFunc [in]

Type: WNDENUMPROC

A pointer to an application-defined callback function.  指向回调函数的指针

For more information, see EnumWindowsProc.

lParam [in]

Type: LPARAM

An application-defined value to be passed to the callback function.  传递给回调函数的参数

Return value

Type:

Type: BOOL

If the function succeeds, the return value is nonzero.    函数执行成功，返回值不为0

If the function fails, the return value is zero. To get extended error information, call GetLastError.   执行失败的话，返回0，并且可以通过GetLastError获取详细的错误信息

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无限的 loop or referencing a handle to a window that has been destroyed.

Note  

For Windows 8 and later, EnumWindows enumerates only top-level windows of desktop apps.