Edit

How to Create a Month Calendar Control

  • Article

This topic demonstrates how to dynamically create a month calendar control by using the CreateWindowEx function.

What you need to know

Technologies

Prerequisites

  • C/C++
  • Windows User Interface Programming

Instructions

To create a month calendar control, use the CreateWindowEx function, specifying MONTHCAL_CLASS as the window class. You must first register the window class by calling the InitCommonControlsEx function, specifying the ICC_DATE_CLASSES bit in the accompanying INITCOMMONCONTROLSEX structure.

The following example demonstrates how to create a month calendar control in an existing modeless dialog box. Note that the size values passed to CreateWindowEx are all zeros. Because the minimum required size depends on the font that the control uses, the example uses the MonthCal_GetMinReqRect macro to request size information and then resizes the control by calling SetWindowPos. If you subsequently change the font with WM_SETFONT, the dimensions of the control will not change. You must call MonthCal_GetMinReqRect again and resize the control to fit the new font.

// Child window identifier of the month calendar.
#define IDC_MONTHCAL 101

// Symbols used by SetWindowPos function (arbitrary values).
#define LEFT 35
#define TOP  40

// Description:
//   Creates a month calendar control in a dialog box.  
// Parameters:
//   hwndOwner - handle of the owner window.
// Nonlocal variables:
//   MonthCalDlgProc - window procedure of the dialog box that 
//     contains the month calendar.
//   g_hInst - global instance handle.
//
HRESULT CreateMonthCalDialog(HWND hwndOwner)
{
    RECT rc;
    INITCOMMONCONTROLSEX icex;
    HWND hwndDlg = NULL;
    HWND hwndMonthCal = NULL;

    // Return an error code if the owner handle is invalid.
    if (hwndOwner == NULL)
        return E_INVALIDARG;

    // Load the window class.
    icex.dwSize = sizeof(icex);
    icex.dwICC  = ICC_DATE_CLASSES;
    InitCommonControlsEx(&icex);

    // Create a modeless dialog box to hold the control.
    hwndDlg = CreateDialog(g_hInst,
                    MAKEINTRESOURCE(IDD_DATE_PICKER),
                    hwndOwner,
                    MonthCalDlgProc);
   
    // Return if creating the dialog box failed. 
    if (hwndDlg == NULL)
        return HRESULT_FROM_WIN32(GetLastError()); 
                        
    // Create the month calendar.
    hwndMonthCal  = CreateWindowEx(0,
                    MONTHCAL_CLASS,
                    L"",
                    WS_BORDER | WS_CHILD | WS_VISIBLE | MCS_DAYSTATE,
                    0,0,0,0, // resize it later
                    hwndDlg,
                    (HMENU) IDC_MONTHCAL,
                    g_hInst,
                    NULL);

    // Return if creating the month calendar failed. 
    if (hwndMonthCal == NULL)
        return HRESULT_FROM_WIN32(GetLastError()); 
                     
    // Get the size required to show an entire month.
    MonthCal_GetMinReqRect(hwndMonthCal, &rc);

    // Resize the control now that the size values have been obtained.
    SetWindowPos(hwndMonthCal, NULL, LEFT, TOP, 
        rc.right, rc.bottom, SWP_NOZORDER);

    // Set the calendar to the annual view.
    MonthCal_SetCurrentView(hwndMonthCal, MCMV_YEAR);

    // Make the window visible.
    ShowWindow(hwndDlg, SW_SHOW);

    return S_OK;
}

Month Calendar Control Reference

About Month Calendar Controls

Using Month Calendar Controls