Month Calendar Control

The month calendar control provides a user interface similar to a calendar, and makes the user be able to select and set the date conveniently. The application can get or set the date by sending message to a month calendar control.

You can create a month calendar control by calling CreateWindow function with CTRL_MONTHCALENDAR as the control class name.

Styles of Month Calendar

A month calendar control can use several forms of Chinese or English and so on to display the date information such as week, month, etc. Specifying the control style to be MCS_CHN, MCS_ENG_L, or MCS_ENG_S can complete this. If a month calendar control has the style MCS_CHN, the control will display the date information in Chinese; if having the style MCS_ENG_L, the control will display the date information in English; and if having the style MCS_ENG_S, the control displays the date information in abbreviate English.

If having the style MCS_NOTIFY, the month calendar control will generate corresponding notification messages in cases such as responding to the user’s operation.

Messages of Month Calendar

Getting Date

MCM_GETCURDAY message is used to get the day of the month of the current selected date:

int day;
day = SendMessage (hwndMonthcal, MCM_GETCURDAY, 0, 0) ;

The return value of SendMessage is the current day of the month, in the range 1 to 31.

MCM_GETCURMONTH message is used to get the number of months of the current selected date:

int month;
month = SendMessage (hwndMonthcal, MCM_GETCURMONTH, 0, 0) ;

The return value of SendMessage is the number of months since January, in the range 0 to 11.

MCM_GETCURYEAR message is used to get the number of years of the current selected date:

int year;
year = SendMessage (hwndMonthcal, MCM_GETCURYEAR, 0, 0) ;

The return value of SendMessage is the current number of years.

MCM_GETCURMONLEN message is used to get the length (how many days in a month) of the current month:

int monthlen;
monthlen = SendMessage (hwndMonthcal, MCM_GETCURMONLEN, 0, 0) ;

The return value of SendMessage is the length of the current month.

MCM_GETFIRSTWEEKDAY message is used to determine which weekday is the first day in the current month:

int weekday;
weekday = SendMessage (hwndMonthcal, MCM_GETFIRSTWEEKDAY, 0, 0) ;

The return value of SendMessage is the weekday number of the first day in the current month. The weekday number is the number of days since Sunday, in the range 0 to 6.

MCM_GETCURDATE message gets the current selected date in a month calendar control:

SYSTEMTIME systime;
SendMessage (hwndMonthcal, MCM_GETCURDATE, 0, (LPARAM)&systime) ;

Here systime is a structure of SYSTEMTIME type, which stores the gotten date information such as year, month, day, and week, etc. This structure is also used for messages such as MCM_GETTODAY and so on. The definition of SYSTEMTIME structure is as follows:

typedef struct _SYSTEMTIME
{
    /* Year */
    int year;
    /* Month */
    int month;
    /* Date */
    int day;
    /* Day */
    int weekday;
} SYSTEMTIME;
typedef SYSTEMTIME *PSYSTEMTIME;

MCM_GETTODAY message gets the date of "today".

SYSTEMTIME systime;
SendMessage (hwndMonthcal, MCM_GETTODAY, 0, (LPARAM)&systime) ;

Here systime is also a structure of SYSTEMTIME type.

Setting Date

It should be noted that special user right (such as root) may needed to set the date in Linux/UNIX system.

MCM_SETCURDAY message sets the current day, MCM_SETCURMONTH message sets the current month, and MCM_SETCURYEAR sets the current year:

int day;
int month;
int year;
SendMessage (hwndMonthcal, MCM_SETCURDAY, day, 0) ;
SendMessage (hwndMonthcal, MCM_SETCURMONTH, month, 0) ;
SendMessage (hwndMonthcal, MCM_SETCURYEAR, year, 0) ;

Here, day, month, and year specify the new day, month and year respectively, and if these values exceed the rational values, the control will adopt the most approached day, month, or year.

MCM_SETCURDATE message sets a specified date as the current selected data:

SYSTEMTIME systime;
SendMessage (hwndMonthcal, MCM_SETCURDATE, 0, (LPARAM)&systime) ;

MCM_SETTODAY sets today as the current selected date:

SendMessage (hwndMonthcal, MCM_SETTODAY, 0, 0) ;

Adjusting Colors

An application can set or get the color of each element in a month calendar control by MCM_GETCOLOR and MCM_SETCOLOR messages:

MCCOLORINFO color;
SendMessage (hwndMonthcal, MCM_GETCOLOR, 0, (LPARAM)&color) ;
SendMessage (hwndMonthcal, MCM_SETCOLOR, 0, (LPARAM)&color) ;

Here color is a structure of MCCOLORINFO, and is used to store color information:

typedef struct _MCCOLORINFO
{
    /* background color of the title */
    int clr_titlebk;
    /* text color of the title */
    int clr_titletext;
    /* color of the arrows */
    int clr_arrow;
    /* background color of the highlighted arrows */
    int clr_arrowHibk;

    /* background color of the weekday */
    int clr_weekcaptbk;
    /* text color of the weekday */
    int clr_weekcapttext;

    /* backgroud color of the day */
    int clr_daybk;
    /* background color of the highlighted day */
    int clr_dayHibk;
    /* text color of the current day */
    int clr_daytext;
    /* text color of the other day */
    int clr_trailingtext;
    /* text color of the hilighted day */
    int clr_dayHitext;
} MCCOLORINFO;

Size of Control

A month calendar has a minimum limit for the window to display content in it normally. MCM_GETMINREQRECTW and MCM_GETMINREQRECTH messages are used to get the minimum width and the minimum height respectively:

int minw, minh;
minw = SendMessage (hwndMonthcal, MCM_GETMINREQRECTW, 0, 0) ;
minh = SendMessage (hwndMonthcal, MCM_GETMINREQRECTH, 0, 0) ;

The return values of SendMessage functions are the minimum width and height.

Notification Codes of Month Calendar

When user clicked month calendar and the currently selected date is changed, the control will generate MCN_DATECHANGE notification code.

Sample Program

Program in List 1 illustrates the use of month calendar control. Please refer to monthcal.c file of the demo program package of this guide for the complete source code.

List 1 Sample Program of month calendar control

#define IDC_MC                100
#define IDC_OK                200

/* Dialog box template: only two controls: month calendar control and “OK” button  */
static CTRLDATA CtrlTime[]=
{
        {
                "monthcalendar",
                WS_CHILD | WS_VISIBLE | MCS_NOTIFY | MCS_ENG_L,
                10, 10, 240, 180,
                IDC_MC,
                "",
                0
        },
        {
                "button",
                WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON,
                260, 180, 50, 22,
                IDC_OK,
                "OK",
                0
        }
};

static DLGTEMPLATE DlgTime =
{
        WS_VISIBLE | WS_CAPTION | WS_BORDER,
        WS_EX_NONE,
        0, 0, 320, 240,
        "Date time",
        0, 0,
        2, CtrlTime,
        0
};

static int TimeWinProc(HWND hDlg, int message, WPARAM wParam, LPARAM lParam)
{
    switch (message) {
        case MSG_INITDIALOG:
        break;

        case MSG_COMMAND:
        {
            int id = LOWORD(wParam);
            if (id == IDC_OK) {
                char info[100];
                 SYSTEMTIME date;
                 /* Get the current date of month calendar */
                 SendMessage (GetDlgItem(hDlg, IDC_MC), MCM_GETCURDATE, 0, (LPARAM)&date);
                 sprintf (info, "You will meet Bush president on  %d.%d.%d",
                                  date.year, date.month, date.day);
                 MessageBox (hDlg, info, "Date", MB_OK);
                 EndDialog (hDlg, 0);
            }
        }
        break;

    case MSG_CLOSE:
        {
            EndDialog (hDlg, 0);
        }
        return 0;
    }

    return DefaultDialogProc (hDlg, message, wParam, lParam);
}
alt

Figure 1 Use of month calendar

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