SetPropA function (winuser.h)

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.

Syntax

BOOL SetPropA(
  [in]           HWND   hWnd,
  [in]           LPCSTR lpString,
  [in, optional] HANDLE hData
);

Parameters

[in] hWnd

Type: HWND

A handle to the window whose property list receives the new entry.

[in] lpString

Type: LPCTSTR

A null-terminated string or 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 must be placed in the low-order word of lpString; the high-order word must be zero.

[in, optional] hData

Type: HANDLE

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

Return value

Type: BOOL

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 a window is destroyed (that is, before it returns from processing the WM_NCDESTROY 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.

SetProp is subject to the restrictions of User Interface Privilege Isolation (UIPI). A process can only call this function on a window belonging to a process of lesser or equal integrity level. When UIPI blocks property changes, GetLastError will return 5.

Examples

For an example, see Adding a Window Property.

Requirements

See also

Conceptual

GlobalAddAtom

Reference

RemoveProp

WM_NCDESTROY

Window Properties

ITaskbarList2::MarkFullscreenWindow