The FindWindowEx function retrieves a handle to a window whose class name and window name match the specified strings. The function searches child windows, beginning with the one following the specified child window. This function does not perform a case-sensitive search.
HWND FindWindowEx( HWND hwndParent,
[in] Handle to the parent window whose child windows are to be searched.
If hwndParent is NULL, the function uses the desktop window as the parent window. The function searches among windows that are child windows of the desktop.
Microsoft® Windows® 2000 and Windows XP: If hwndParent is HWND_MESSAGE, the function searches all message-only windows.
[in] Handle to a child window. The search begins with the next child window in the Z order. The child window must be a direct child window of hwndParent, not just a descendant window.
If hwndChildAfter is NULL, the search begins with the first child window of hwndParent.
Note that if both hwndParent and hwndChildAfter are NULL, the function searches all top-level and message-only windows.
Pointer to a null-terminated string that specifies the class name or a class atom created by a previous call to the RegisterClass or RegisterClassEx function. The atom must be placed in the low-order word of lpszClass; the high-order word must be zero.
If lpszClass is 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, or it can be MAKEINTATOM(0x800). In this latter case, 0x8000 is the atom for a menu class. For more information, see the Remarks section of this topic.
[in] Pointer to a null-terminated string that specifies the window name (the window's title). If this parameter is NULL, all window names match.
If the function succeeds, the return value is a handle to the window that has the specified class and window names.
If the function fails, the return value is NULL. To get extended error information, call GetLastError.
If the lpszWindow parameter is not NULL, FindWindowEx calls the GetWindowText function to retrieve the window name for comparison. For a description of a potential problem that can arise, see the Remarks section of GetWindowText.
An application can call this function in the following way.
FindWindowEx( NULL, NULL, MAKEINTATOM(0x8000), NULL );
0x8000 is the atom for a menu class. When an application calls this function, the function checks whether a context menu is being displayed that the application created.
Windows 95 or later: FindWindowExW is supported by the Microsoft Layer for Unicode (MSLU). To use this, you must add certain files to your application, as outlined in Microsoft Layer for Unicode on Windows 95/98/Me Systems.