WinSetWindowULong

This function sets an unsigned, long integer value into the memory of the reserved window words.

Syntax

WinSetWindowULong(hwnd, index, ul)

Parameters

hwnd (HWND) - Input

Window handle.

index (LONG) - Input

Zero-based index of the value to be set.

The units of index are bytes. Valid values are zero through (cbWindowData - 4), where cbWindowData is the parameter in WinRegisterClass that specifies the number of bytes available for application-defined storage. Any of the QWL_* values are also valid.

Note: QWS_* values cannot be used.

QWL_DEFBUTTON The default push button for a dialog. The default push button is the one that sends its WM_COMMAND message when the enter key is pressed.

QWL_HMQ Handle of message queue of window. Note that the leading 16 bits of this value are zero.

QWL_HWNDFOCUSSAVE Window handle of the child windows of this window that last possessed the focus when this frame window was last deactivated.

QWL_PENDATA Reserved for use by operating system extensions. It allows an operating system extension to store data on a per window basis.

QWL_STYLE Window style.

QWL_USER A ULONG value for applications to use is present at offset QWL_USER in windows of the following preregistered window classes:

WC_BUTTON

WC_COMBOBOX

WC_CONTAINER

WC_ENTRYFIELD

WC_FRAME (includes dialog windows)

WC_LISTBOX

WC_MENU

WC_MLE

WC_NOTEBOOK

WC_SCROLLBAR

WC_SLIDER

WC_SPINBUTTON

WC_STATIC

WC_TITTLEBAR

WC_VALUESET

This value can be used to place application-specific data in controls.

Other Zero-based index.

ul (ULONG) - Input

Unsigned, long integer value to store in the window words.

Returns

rc (BOOL) - returns: TRUE Successful completion; FALSE Error occurred.

Remarks

The specified index is valid only if all of the bytes referenced are within the reserved memory.

Errors

Possible returns from WinGetLastError:

PMERR_INVALID_HWND (0x1001) An invalid window handle was specified.
PMERR_PARAMETER_OUT_OF_RANGE (0x1003) The value of a parameter was not within the defined valid range for that parameter.

Example Code

#define INCL_WINWINDOWMGR /* Or use INCL_WIN, INCL_PM, */
#include <os2.h>

HWND   hwnd;   /*  Window handle. */
LONG   index;  /*  Zero-based index of the value to be set. */
ULONG  ul;     /*  Unsigned, long integer value to store in the window words. */
BOOL   rc;     /*  Success indicator. */

rc = WinSetWindowULong(hwnd, index, ul);

This example transfers a pointer from the application-defined data area of a dialog window to the application-defined data area (window word) of a main window. The pointer is then retrieved.

#define INCL_WINWINDOWMGR
#include <OS2.H>

HWND hwndClient;
ULONG  msg;
MPARAM pParm, mp1, mp2;

/* Inside dialog procedure */
switch( msg )
{
  case WM_INITDLG:
    /* This points to the data area and is passed by */
    /* WinLoadDlg, WinCreateDlg, and WinDlgBox      */
    /* in their pCreateParams parameter.            */
    pParm = (MPARAM)mp2;

    /* Place the pointer in the window word area */
    WinSetWindowULong(hwndClient,
                      QWL_USER,
                      (ULONG) pParm);

    case WM_COMMAND:
        switch (SHORT1FROMMP(mp1))
        {
           case DID_OK:
              /* Retrieve the pointer from the window word area */
              pParm = (MPARAM)WinQueryWindowULong(hwndClient,
                                                   QWL_USER);
        }
}

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