SetProp

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
);
 

Parameters

hWnd

Handle to the window whose property list receives the new entry.

lpString

Pointer to a null-terminated string or contains an atom that identifies a string. If this parameter is an atom, it must be a global atom created by a previous call to the GlobalAddAtom function. The atom, a 16-bit value, must be placed in the low-order word of lpString; the high-order word must be zero.

hData

Handle to the data to be copied to the property list. The data handle can identify any value useful to the application.

Return Values

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.

Remarks

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.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in winuser.h.
  Import Library: Use user32.lib.
  Unicode: Implemented as Unicode and ANSI versions on Windows NT.

See Also

Window Properties Overview, Window Property Functions, EnumProps, EnumPropsEx, GetProp, GlobalAddAtom, RemoveProp