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Calendar.OnSelectionChanged Method

Definition

Raises the SelectionChanged event of the Calendar control and allows you to provide a custom handler for the SelectionChanged event.

protected:
 virtual void OnSelectionChanged();
protected virtual void OnSelectionChanged ();
abstract member OnSelectionChanged : unit -> unit
override this.OnSelectionChanged : unit -> unit
Protected Overridable Sub OnSelectionChanged ()

Examples

The following code example demonstrates how to specify and code a handler for the SelectionChanged event to display the number of items selected in the Calendar control.

<%@ Page Language="C#" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Calendar SelectionChanged Example</title>
<script runat="server">

      void Selection_Change(Object sender, EventArgs e) 
      {
 
         // Clear the current text.
         Message.Text = "";

         // Iterate through the SelectedDates collection and display the
         // dates selected in the Calendar control.
         foreach(DateTime day in Calendar1.SelectedDates)
         {

            Message.Text += day.Date.ToShortDateString() + "<br />";

         }
         
      }

   </script>

</head>     
<body>

   <form id="form1" runat="server">

      <h3>Calendar SelectionChanged Example</h3>

      Select dates on the Calendar control.<br /><br />

      <asp:Calendar ID="Calendar1" runat="server"  
           SelectionMode="DayWeekMonth" 
           ShowGridLines="True"             
           OnSelectionChanged="Selection_Change">

         <SelectedDayStyle BackColor="Yellow"
                           ForeColor="Red">
         </SelectedDayStyle>

      </asp:Calendar>

      <hr />

      <table border="1">

         <tr style="background-color:silver">

            <th>

               Selected Dates:

            </th>
         </tr>

         <tr>

            <td>
           
               <asp:Label id="Message" 
                    Text="No dates selected." 
                    runat="server"/>

            </td>

         </tr>

      </table>

   </form>

</body>

</html>
<%@ Page Language="VB" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Calendar SelectionChanged Example</title>
<script runat="server">

      Sub Selection_Change(sender As Object, e As EventArgs) 
 
         ' Clear the current text.
         Message.Text = ""

         ' Iterate through the SelectedDates collection and display the
         ' dates selected in the Calendar control.
         Dim day As DateTime

         For Each day In Calendar1.SelectedDates

            Message.Text &= day.Date.ToShortDateString() & "<br />"

         Next
         
      End Sub

   </script>

</head>     
<body>

   <form id="form1" runat="server">

      <h3>Calendar SelectionChanged Example</h3>

      Select dates on the Calendar control.<br /><br />

      <asp:Calendar ID="Calendar1" runat="server"  
           SelectionMode="DayWeekMonth" 
           ShowGridLines="True"             
           OnSelectionChanged="Selection_Change">

         <SelectedDayStyle BackColor="Yellow"
                           ForeColor="Red">
         </SelectedDayStyle>

      </asp:Calendar>

      <hr />

      <table border="1">

         <tr style="background-color:silver">

            <th>

               Selected Dates:

            </th>
         </tr>

         <tr>

            <td>
           
               <asp:Label id="Message" 
                    Text="No dates selected." 
                    runat="server"/>

            </td>

         </tr>

      </table>

   </form>

</body>

</html>
<%@ Page Language="C#" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Calendar SelectionChanged Example</title>
<script runat="server">

      void Selection_Change(Object sender, EventArgs e) 
      {
 
         // Clear the current text.
         Message.Text = "";

         // Iterate through the SelectedDates collection and display the
         // dates selected in the Calendar control.
         foreach(DateTime day in Calendar1.SelectedDates)
         {

            Message.Text += day.Date.ToShortDateString() + "<br />";

         }
         
      }

      void Page_Load(Object sender, EventArgs e)
      {

         // Manually register the event-handling method for the  
         // SelectionChanged event of the Calendar control.
         Calendar1.SelectionChanged += new EventHandler(this.Selection_Change);

      }


   </script>

</head>     
<body>

   <form id="form1" runat="server">

      <h3>Calendar SelectionChanged Example</h3>

      Select a day, week, or month on the Calendar control.<br /><br />

      <asp:Calendar ID="Calendar1" runat="server"  
           SelectionMode="DayWeekMonth" 
           ShowGridLines="True">

         <SelectedDayStyle BackColor="Yellow"
                           ForeColor="Red">
         </SelectedDayStyle>

      </asp:Calendar>

      <hr />

      <table border="1">

         <tr style="background-color:silver">

            <th>

               Selected dates

            </th>
         </tr>

         <tr>

            <td>
           
               <asp:Label id="Message" 
                    Text="No dates selected." 
                    runat="server"/>

            </td>

         </tr>

      </table>

   </form>

</body>

</html>
<%@ Page Language="VB" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Calendar SelectionChanged Example</title>
<script runat="server">

      Sub Selection_Change(sender As Object, e As EventArgs) 
 
         ' Clear the current text.
         Message.Text = ""

         ' Iterate through the SelectedDates collection and display the
         ' dates selected in the Calendar control.
         Dim day As DateTime

         For Each day In Calendar1.SelectedDates

            Message.Text &= day.Date.ToShortDateString() & "<br />"

         Next
         
      End Sub

      Sub Page_Load(sender As Object, e As EventArgs)

         ' Manually register the event-handling method for the   
         ' SelectionChanged event of the Calendar control.
         AddHandler Calendar1.SelectionChanged, AddressOf Selection_Change

      End Sub

   </script>

</head>     
<body>

   <form id="form1" runat="server">

      <h3>Calendar SelectionChanged Example</h3>

      Select a day, week, or month on the Calendar control.<br /><br />

      <asp:Calendar ID="Calendar1" runat="server"  
           SelectionMode="DayWeekMonth" 
           ShowGridLines="True">

         <SelectedDayStyle BackColor="Yellow"
                           ForeColor="Red">
         </SelectedDayStyle>

      </asp:Calendar>

      <hr />

      <table border="1">

         <tr style="background-color:silver">

            <th>

               Selected Dates:

            </th>
         </tr>

         <tr>

            <td>
           
               <asp:Label id="Message" 
                    Text="No dates selected." 
                    runat="server"/>

            </td>

         </tr>

      </table>

   </form>

</body>

</html>

Remarks

The SelectionChanged event is raised when the user selects a day, a week, or an entire month by clicking the date selector controls.

Raising an event invokes the event handler through a delegate. For more information, see Handling and Raising Events.

The OnSelectionChanged method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

Notes to Inheritors

When overriding OnSelectionChanged() in a derived class, be sure to call the base class's OnSelectionChanged() method so that registered delegates receive the event.

Applies to

See also