Sets the display for days in a month calendar control.

BOOL SetDayState(
   int nMonths,



Value indicating how many elements are in the array that pStates points to.


A pointer to a MONTHDAYSTATE array of values that define how the month calendar control will draw each day in its display. The MONTHDAYSTATE data type is a bit field, where each bit (1 through 31) represents the state of a day in a month. If a bit is on, the corresponding day will be displayed in bold; otherwise it will be displayed with no emphasis.

Nonzero if successful; otherwise 0.

This member function implements the behavior of the Win32 message MCM_SETDAYSTATE, as described in the Platform SDK.

void CDatesDlg::OnButton2() 
   // Gain a pointer to the control

   CMonthCalCtrl* pCtrl = (CMonthCalCtrl*) GetDlgItem(IDC_MONTHCALENDAR1);
   ASSERT(pCtrl != NULL);

   // First, we must find the visible range. The array we pass to the
   // SetDayState() function must be large enough to hold days for all
   // of the visible months. Even if a month is _partially_ visible,
   // we must have MONTHDAYSTATE data for it in the array we pass.
   // GetMonthRange() returns the range of days currently visible in
   // the control, along with a count of visible months. This array
   // will be up to 2 months larger than the number of "pages" visible
   // in the control.

   SYSTEMTIME timeFrom;
   SYSTEMTIME timeUntil;
   int nCount = pCtrl->GetMonthRange(&timeFrom, &timeUntil, GMR_DAYSTATE);

   // Allocate the state array based on the return value.

   pDayState = new MONTHDAYSTATE[nCount];
   memset(pDayState, 0, sizeof(MONTHDAYSTATE) * nCount);

   // Find the first fully visible month.

   int nIndex = (timeFrom.wDay == 1) ? 0 : 1;

   // Set the 4th day, 19th day, and 26th day of the first
   // _fully_ visible month as bold.

   pDayState[nIndex] |= 1 << 3;   // 4th day
   pDayState[nIndex] |= 1 << 18;   // 19th day
   pDayState[nIndex] |= 1 << 25;   // 25th day

   // Set state and clean up

   VERIFY(pCtrl->SetDayState(nCount, pDayState));
   delete [] pDayState;

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