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GetClassWord function

Retrieves the 16-bit (WORD) value at the specified offset into the extra class memory for the window class to which the specified window belongs.

Note  This function is deprecated for any use other than nIndex set to GCW_ATOM. The function is provided only for compatibility with 16-bit versions of Windows. Applications should use the GetClassLongPtr or GetClassLongPtr function.

Syntax


WORD WINAPI GetClassWord(
  _In_ HWND hWnd,
  _In_ int  nIndex
);

Parameters

hWnd [in]

Type: HWND

A handle to the window and, indirectly, the class to which the window belongs.

nIndex [in]

Type: int

The zero-based byte offset of the value to be retrieved. Valid values are in the range zero through the number of bytes of class memory, minus two; for example, if you specified 10 or more bytes of extra class memory, a value of eight would be an index to the fifth 16-bit integer. There is an additional valid value as shown in the following table.

ValueMeaning
GCW_ATOM
-32

Retrieves an ATOM value that uniquely identifies the window class. This is the same atom that the RegisterClass or RegisterClassEx function returns.

 

Return value

Type:

Type: WORD

If the function succeeds, the return value is the requested 16-bit value.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

Reserve extra class memory by specifying a nonzero value in the cbClsExtra member of the WNDCLASS structure used with the RegisterClass function.

Requirements

Minimum supported client

Windows 2000 Professional [desktop apps only]

Minimum supported server

Windows 2000 Server [desktop apps only]

Header

Winuser.h (include Windows.h)

Library

User32.lib

DLL

User32.dll

See also

Reference
GetClassLong
RegisterClass
RegisterClassEx
SetClassWord
WNDCLASS
Conceptual
Window Classes

 

 

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