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Date-Time Pickers

You can set a date and time in a date-time picker just by editing the displayed values in the control; if you click the arrow in the date-time picker, it displays a month calendar, just as a combo box would display a drop-down list; you can make selections just by clicking the calendar.

You can limit the date and times that can be selected in a date-time picker by setting the MinDate and MaxDate properties. And you can change the look of the calendar part of the control by setting the CalendarForeColor, Calendar Font, CalendarTitleBackColor, CalendarTitleForeColor, CalendarTrailing ForeColor, and CalendarMonthBackground properties.

When the user makes a selection, the new selection appears in the text box part of the date-time picker, and a ValueChanged event occurs. You can get the new text in the text box part of the control with the Text property, or as a Visual Basic DateTime object with the Value property. DateTime objects are good to know about. (We'll use them in several places in this chapter.) You can find the static properties of this class (the class properties that you can use with the class alone, without needing to create a DateTime object) in Table 8.1, the public properties of DateTime objects in Table 8.2, and the public object methods in Table 8.3.

Table 8.1: Noteworthy public shared (static) properties of the Date Time class.

Property	Means
Now	Holds a DateTime object holding the current local time.
Today	Holds a DateTime object holding the current date.
UtcNow	Holds a DateTime object holding the current local time in universal time (UTC).

Table 8.2: Noteworthy public properties of DateTime objects.

Property	Means
Date	Holds the date of this object.
Day	Holds the day of the month of this object.
DayOfWeek	Holds the day of the week of this object.
DayOfYear	Holds the day of the year of this object.
Hour	Holds the hour part of the date of this object.
Millisecond	Holds the milliseconds (thousandths of a second) part of the time represented by this object.
Minute	Holds the minutes of the time in this object.
Month	Holds the month part of the date in this object.
Second	Holds the seconds part of the date in this object.
Ticks	Holds the number of 100-nanosecond ticks that represent the date and time of this object.
TimeOfDay	Holds the time of day for this object.
Year	Holds the year part of the date in this object.

Table 8.3: Noteworthy public methods of DateTime objects.

Method	Means
Add	Adds a TimeSpan object to this object.
AddDays	Adds a number of days to this object.
AddHours	Adds a number of hours to this object.
AddMilliseconds	Adds a number of milliseconds to this object.
AddMinutes	Adds a number of minutes to this object.
AddMonths	Adds a number of months to this object.
AddSeconds	Adds a number of seconds to this object.
AddTicks	Adds a number of ticks to this object.
AddYears	Adds a number of years to this object.
CompareTo	Compares this object to another object, returning a value indicating their relative values.
Equals	Indicates if an object is equal to another object.
Subtract	Subtracts a time from this object.
ToFileTime	Converts this object to local time format.
ToLocalTime	Converts coordinated universal time (UTC) to local time.
ToLongDateString	Converts this object to its equivalent long date String value.
ToLongTimeString	Converts this object to its equivalent long time String value.
ToShortDateString	Converts this object to its equivalent short date String value.
ToShortTimeString	Converts this object to its equivalent short time String value.
ToString	Converts this object to its equivalent String value.
ToUniversalTime	Converts the local time to universal time (UTC).

The Format property sets the DateTimePickerFormat property of the control. The default date Format is DateTimePickerFormat.Long. If the Format property is set to DateTimePickerFormat.Custom, you can create your own format style by setting the CustomFormat property and using a custom format string. The custom format string can be a combination of custom field characters and other literal characters; see "Setting Date-Time Picker Custom Formats" later in this chapter.

To use an up-down style control to adjust the date-time value, set the ShowUpDown property to True. In this case, the calendar control will not drop down when the control is selected—here, the date and time can be set by selecting each item individually and using the up and down buttons in the control.

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Month Calendar Controls

The month calendar control allows the user to select a date and time visually, as you can see in Figure 8.4. You can limit the date and times that can be selected by setting the MinDate and MaxDate properties. When a new date is selected, a DateSelected event occurs, and when the date is changed, a DateChanged event occurs. Because the user can use the mouse to select a range of dates, you can use the month calendar control's SelectionRange property to determine which date or dates have been selected.

The SelectionRange property returns a SelectionRange object. This has two useful properties: Start and End, which return DateTime objects corresponding to the start and end of the selected date. If only one date has been selected, both Start and End will point to that date. For example, the currently selected starting day in a month calendar control would be MonthCalendar1.Selection Range.Start.Day.

You also can use the month calendar control's SelectionStart and SelectionEnd properties to directly access the start and end dates selected without using the SelectionRange properties at all. Both of these properties return DateTime objects as well. And note also that you can change the look of the calendar part of the control by setting the ForeColor, font, TitleBackColor, TitleForeColor, TrailingForeColor, and BackColor properties.