The SetProp function adds a new entry or changes an existing entry in the property list of the specified window. The function adds a new entry to the list if the specified character string does not exist already in the list. The new entry contains the string and the handle. Otherwise, the function replaces the string’s current handle with the specified handle.
BOOL SetProp(
HWND hWnd, |
// handle of window |
LPCTSTR lpString, |
// atom or address of string |
HANDLE hData |
// handle of data |
); |
If the data handle and string are added to the property list, the return value is nonzero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.
Before destroying a window (that is, before processing the WM_DESTROY message), an application must remove all entries it has added to the property list. The application must use the RemoveProp function to remove the entries.