ARTICLE

WPF Calendar Control in VB.NET

Posted by Dinesh Beniwal in Articles | WPF using VB.NET on May 07, 2010

Tags: VB.NET, Calendar Control, WPF Calendar, XAML

A Calendar control is used to create a visual calendar that let users pick a date and fire an event on the selection of the date. This article demonstrates how to create and use a Calendar control in WPF using XAML and VB.NET.

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Reader Level: Beginner

WPF Calendar Control

Creating a Calendar

The Calendar element represents a WPF calendar control in XAML.

The Calendar control is defined in the System.Windows.Controls namespace. When you drag and drop a Calendar control from Toolbox to the page, the XAML code will look like following code where you can see a Calendar XAML element is added within the Grid element and its Width, Height, Name, and VerticalAlignment and HorizontalAlignment attributes are set.

<Grid>
<Calendar Height="170" HorizontalAlignment="Left" Margin="58,32,0,0"
Name="calendar1" VerticalAlignment="Top" Width="180" />
</Grid>

The Width and Height attributes of the Calendar element represent the width and the height of a Calendar. The Content attribute represents the text of a Calendar. The Name attribute represents the name of the control, which is a unique identifier of a control.

The code snippet in Listing 1 creates a Calendar control and sets the name, height, and width properties of a Calendar control.

Listing 1

Display Modes

The DisplayMode property of the Calendar class represents the format of display of a Calendar, which can be a month, year, or decade. Month is the default mode. By setting the DisplayMode to Year and Decade generates Figure 2 and Figure 3 respectively.

Figure 2

Figure 3

The Month view that is also the default view looks like Figure 4.

Figure 4

If you take an example of the Decade, and click on year 2008 in Figure 3, you will get another Calendar format with all months in year 2008 and if you click on any month, you will eventually get the month view of the Calendar.

The following code snippet sets the DisplayMode property to Decade.

Selection Modes and Selection Dates

The SelectedDate property represents the currently selected date. If multiple dates selection is true, the SelectedDates property represents a collection of currently selected dates.

The SelectionMode of type CalendarSelectionMode enumeration represents the selection mode of calendar. Table 1 describes the CalendarSelectionMode enumeration and its members.

CalendarSelectionMode	Description
None	No selections are allowed.
SingleDate	Only a single date can be selected, either by setting SelectedDate or the first value in SelectedDates. AddRange cannot be used.
SingleRange	A single range of dates can be selected. Setting SelectedDate, adding a date individually to SelectedDates, or using AddRange will clear all previous values from SelectedDates.
MultipleRange	Multiple non-contiguous ranges of dates can be selected. Adding a date individually to SelectedDates or using AddRange will not clear SelectedDates. Setting SelectedDate will still clear SelectedDates, but additional dates or range can then be added. Adding a range that includes some dates that are already selected or overlaps with another range results in the union of the ranges and does not cause an exception.

The following code snippet sets the SelectionMode property to single range.

BlackoutDates

The BlackoutDates property of the Calendar class represents a collection of dates that are not available for selection. All non selection dates are marked by a cross. For example, say in March month of year 2010, we would like to block dates from Jan 1^st to Jan 7^th and then all Sundays and the final calendar should look like Figure 5.

Figure 5

The following code snippet adds backout dates to a Calendar.

<Calendar.BlackoutDates>
    <CalendarDateRange Start="3/1/2010" End="3/7/2010"/>
    <CalendarDateRange Start="3/8/2010" End="3/8/2010"/>
    <CalendarDateRange Start="3/15/2010" End="3/15/2010"/>
    <CalendarDateRange Start="3/22/2010" End="3/22/2010"/>
    <CalendarDateRange Start="3/29/2010" End="3/29/2010"/>
</Calendar.BlackoutDates>

We can achieve this by adding code listed in Listing 2. As you can see from Listing 3, the BlackoutDates.Add method takes a CalendarDateRange object, which is a collection of two DateTime objects. The first date is the start date of the range and second date is the end date of the date range.

    Private Sub SetBlackOutDates()
        MonthlyCalendar.BlackoutDates.Add(New CalendarDateRange(New DateTime(2010, 3, 1), New DateTime(2010, 3, 7)))
        MonthlyCalendar.BlackoutDates.Add(New CalendarDateRange(New DateTime(2010, 3, 8), New DateTime(2010, 3, 8)))
        MonthlyCalendar.BlackoutDates.Add(New CalendarDateRange(New DateTime(2010, 3, 15), New DateTime(2010, 3, 15)))
        MonthlyCalendar.BlackoutDates.Add(New CalendarDateRange(New DateTime(2010, 3, 22), New DateTime(2010, 3, 22)))
        MonthlyCalendar.BlackoutDates.Add(New CalendarDateRange(New DateTime(2010, 3, 29), New DateTime(2010, 3, 29)))
    End Sub

Listing 2

DisplayDateStart and DisplayDateEnd

The Calendar control allows you to set the start and end display dates by using the DisplayDateStart and DisplayDateEnd properties. If you see Figure 5 in the previous section, you may notice the March 2010 month calendar display start with March 01, 2010 date. But now what if you want to display dates for March 2010 month only? We can use the DisplayStartDate and DisplayEndDate properties to control the start and end dates of a month.

DisplayDate property represents the current date to display.

The following code snippet sets the DisplayDate, DisplayDateStart and DisplayDateEnd attributes of Calendar element in XAML.

The code listed in Listing 3 makes sure the start date is March 01, 2010 and end date is March 31, 2010. The current selected date is March 05.

    Private Sub SetDisplayDates()
        MonthlyCalendar.DisplayDate = New DateTime(2010, 3, 5)
        MonthlyCalendar.DisplayDateStart = New DateTime(2010, 3, 1)
        MonthlyCalendar.DisplayDateEnd = New DateTime(2010, 3, 31)
    End Sub

Listing 3

The new calendar looks like Figure 6.

Figure 6

FirstDayOfWeek and IsTodayHighlighted

By default, Sunday is the first day of week. If you would like to change it, you use FirstDayOfWeek property. The IsTodayHightlighted property is used to make today highlighted.

The following code snippet sets the FirstDayOfWeek to Tuesday and makes today highlighted.

The following code snippet sets the FirstDayOfWeek to Tuesday and makes today highlighted in WPF.

MonthlyCalendar.FirstDayOfWeek = DayOfWeek.Tuesday
MonthlyCalendar.IsTodayHighlighted = True

The new calendar looks like Figure 7, where you can see the start day of the week us Tuesday.

Figure 7

Selected Date and Selected Dates

SelectedDate property represents the current selected date. If multiple date selection is true, then SelectedDates property represents all selected dates in a Calendar. The following code snippet sets the SelectedDates in XAML at design-time.

    <Calendar.SelectedDates>
        <sys:DateTime>3/5/2010</sys:DateTime>
        <sys:DateTime>3/15/2010</sys:DateTime>
        <sys:DateTime>3/25/2010</sys:DateTime>
     </Calendar.SelectedDates>

</Calendar>

The selected dates in a Calendar looks like Figure 8 where you can see March 5^th, 15^th, and 25^th have a light blue background and represents the selected dates.

Figure 8

The following code snippet sets the SelectedDates property in WPF at run-time.

    Private Sub AddSelectedDates()
        MonthlyCalendar.SelectedDates.Add(New DateTime(2010, 3, 5))
        MonthlyCalendar.SelectedDates.Add(New DateTime(2010, 3, 15))
        MonthlyCalendar.SelectedDates.Add(New DateTime(2010, 3, 25))
    End Sub

Note: If you set selected dates to any of the blockout dates, you will see parser in XAML will through an error like Figure 9.

Figure 9

Calendar Events

Besides the normal control events, the Calendar control has three events calendar related events. These events are the DisplayDateChanged, DisplayModeChanged, and SelectedDatesChanged. The DisplayDateChanged event is fired where the DisplayDate property is changed. The DisplayModeChanged event is fired when the DisplayMode property is changed. The SelectedDatesChanged event is fired when the SelectedDate or SelectedDates properties are changed. The following code snippet sets these three events attributes.

The code behind for these events looks like Listing 4.

Private Sub MonthlyCalendar_SelectedDatesChanged(ByVal sender As Object, ByVal e As SelectionChangedEventArgs)
End Sub

Private Sub MonthlyCalendar_DisplayDateChanged(ByVal sender As Object, ByVal e As CalendarDateChangedEventArgs)
End Sub

Private Sub MonthlyCalendar_DisplayModeChanged(ByVal sender As Object, ByVal e As CalendarModeChangedEventArgs)
End Sub

Listing 4

Normally, on a date selection, you may want to capture that event and know what the current selected date is. Now how about we add a TextBox control to the page and on the date selection, we are going to set the text of the TextBox to the currently selected date.

We add the following code to the XAML just below the Calendar control.

</TextBox>

On the SelectedDateChanged event handler, we set the TextBox.Text property to the SelectedDate property of the Calendar control as you can see from code in Listing 5.

    Private Sub MonthlyCalendar_SelectedDatesChanged(ByVal sender As Object, ByVal e As SelectionChangedEventArgs)
        SelectedDateTextBox.Text = MonthlyCalendar.SelectedDate.ToString()
    End Sub

Listing 5

Now when you run the application, you will see output looks like Figure 10. When you select a date in the Calendar, it will be displayed in the Textbox.

Figure 10

Formatting a Calendar

How about we create a Calendar control with a border formatting, background, and foreground of the Calendar?

The BorderBrush property of the Calendar sets a brush to draw the border of a Calendar. You may use any brush to fill the border. The following code snippet uses a linear gradient brush to draw the border with a combination of red and blue color.

<Calendar.BorderBrush>
    <LinearGradientBrush StartPoint="0,0" EndPoint="1,1" >
        <GradientStop Color="Blue" Offset="0" />
        <GradientStop Color="Red" Offset="1.0" />
    </LinearGradientBrush>
</Calendar.BorderBrush>

The Background and Foreground properties of the Calendar set the background and foreground colors of a Calendar. You may use any brush to fill the border. The following code snippet uses linear gradient brushes to draw the background and foreground of a Calendar.

<Calendar.Background>
    <LinearGradientBrush StartPoint="0,0" EndPoint="1,1" >
        <GradientStop Color="Blue" Offset="0.1" />
        <GradientStop Color="Orange" Offset="0.25" />
        <GradientStop Color="Green" Offset="0.75" />
        <GradientStop Color="Red" Offset="1.0" />
    </LinearGradientBrush>
</Calendar.Background>
<Calendar.Foreground>
    <LinearGradientBrush StartPoint="0,0" EndPoint="1,1" >
        <GradientStop Color="Black" Offset="0.25" />
        <GradientStop Color="Green" Offset="1.0" />
    </LinearGradientBrush>
</Calendar.Foreground>

The new Calendar looks like Figure 11.

Figure 11

Setting Image as Background of a Calendar

To set an image as background of a Calendar, we can set an image as the Background of the Calendar. The following code snippet sets the background of a Calendar to an image. The code also sets the opacity of the image.

<Calendar.Background>
<ImageBrush ImageSource="Garden.jpg" Opacity="0.3"/>
</Calendar.Background>

The new output looks like Figure 12.

Figure 12

Creating a Calendar Dynamically

The code listed in Listing 6 creates a Calendar control programmatically. First, it creates a Calendar object and sets its DisplayMode and SelectedMode and other properties and later the Calendar is added to the LayoutRoot.

   Private Sub CreateDynamicCalendar()
        Dim MonthlyCalendar As New Calendar()
        MonthlyCalendar.Name = "MonthlyCalendar"
        MonthlyCalendar.Width = 300
        MonthlyCalendar.Height = 400
        MonthlyCalendar.Background = Brushes.LightBlue
        MonthlyCalendar.DisplayMode = CalendarMode.Month
        MonthlyCalendar.SelectionMode = CalendarSelectionMode.SingleRange
        MonthlyCalendar.DisplayDateStart = New DateTime(2010, 3, 1)
        MonthlyCalendar.DisplayDateEnd = New DateTime(2010, 3, 31)
        MonthlyCalendar.SelectedDates.Add(New DateTime(2010, 3, 5))
        MonthlyCalendar.SelectedDates.Add(New DateTime(2010, 3, 15))
        MonthlyCalendar.SelectedDates.Add(New DateTime(2010, 3, 25))
        MonthlyCalendar.FirstDayOfWeek = DayOfWeek.Monday
        MonthlyCalendar.IsTodayHighlighted = True
        LayoutRoot.Children.Add(MonthlyCalendar)
    End Sub

Listing 6

Summary

In this article, I discussed how we can create a Calendar control in WPF and VB.NET. We also saw how to set display modes, selection modes, blackout dates, selected dates, border, background, and foreground properties. After that, we saw you to set an image as the background of a Calendar. In the end of this article, we saw how to create a Calendar dynamically.