Modifier

Partager via

SelectedDatesCollection.Clear Method

  • Reference

Definition

Namespace:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Removes all DateTime objects from the collection.

public:
 void Clear();
public void Clear ();
member this.Clear : unit -> unit
Public Sub Clear ()

Examples

The following code example demonstrates how to use the Clear method to remove all System.DateTime objects from the SelectedDatesCollection collection and replace them with new System.DateTime objects.

<%@ 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>
    <title>SelectedDatesCollection Add Example </title>
<script runat="server">

      void Page_Load(Object sender, EventArgs e)
      {

         // Initialize the VisibleDate property with today's date when
         // the page is first loaded.
         if(!IsPostBack)
         {

            Calendar1.VisibleDate = Calendar1.TodaysDate;

         }

      }
     
      void Button_Click(Object sender, EventArgs e) 
      {

         // This method demonstrates how to select noncontiguous dates 
         // in the calendar. 
  
         // Get the month and year of the date contained in the 
         // VisibleDate property.
         int CurrentMonth = Calendar1.VisibleDate.Month;
         int CurrentYear = Calendar1.VisibleDate.Year;
   
         // Clear all selected dates.
         Calendar1.SelectedDates.Clear();
   
         // Iterate through the current month and add all Wednesdays 
         // to the collection.
         for (int i = 1; 
             i <= System.DateTime.DaysInMonth(CurrentYear, CurrentMonth);
              i++)
         {

            DateTime CurrentDate = new DateTime(CurrentYear, CurrentMonth, i);

            if (CurrentDate.DayOfWeek == DayOfWeek.Wednesday)
            {
               Calendar1.SelectedDates.Add(CurrentDate);
            }

         }
 
         // Display the number of items selected.
         Message.Text = "Selection Count = " + 
             Calendar1.SelectedDates.Count.ToString();
 
      }
 
      void Selection_Change(Object sender, EventArgs e) 
      {

         // Display the number of items selected.
         Message.Text = "Selection Count = " + 
             Calendar1.SelectedDates.Count.ToString();

      }
 
   </script>
 
</head>     
<body>
 
   <form id="form1" runat="server">

      <h3>SelectedDatesCollection Add Example </h3>

      Click the button to select all Wednesdays in the month.

      <br /><br />
 
      <asp:Calendar ID="Calendar1" runat="server"  
           SelectionMode="DayWeekMonth" 
           OnSelectionChanged="Selection_Change" />
 
      <hr />
 
      <asp:Button id="SubmitButton"
           Text="Select All Weds in Month" 
           OnClick="Button_Click"  
           runat="server"  /> 

      <br />
 
      <asp:Label id="Message" 
           runat="server" />

   </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>
    <title>SelectedDatesCollection Add Example </title>
<script runat="server">

      Sub Page_Load(sender As Object, e As EventArgs)

         ' Initialize the VisibleDate property with today's date when
         ' the page is first loaded.
         If Not IsPostBack Then

            Calendar1.VisibleDate = Calendar1.TodaysDate

         End If

      End Sub
     
      Sub Button_Click(sender As Object, e As EventArgs) 

         ' This method demonstrates how to select noncontiguous dates 
         ' in the calendar. 
  
         ' Get the month, day, and year of the date contained in the 
         ' VisibleDate property.
         Dim CurrentMonth As Integer = Calendar1.VisibleDate.Month
         Dim CurrentYear As Integer = Calendar1.VisibleDate.Year
   
         ' Clear all selected dates.
         Calendar1.SelectedDates.Clear()
   
         ' Iterate through the current month and add all Wednesdays 
         ' to the collection.
         Dim i As Integer

         For i = 1 To System.DateTime.DaysInMonth(CurrentYear, CurrentMonth)

            Dim CurrentDate As DateTime = _
                New DateTime(CurrentYear, CurrentMonth, i)

            If CurrentDate.DayOfWeek = DayOfWeek.Wednesday Then
            
                Calendar1.SelectedDates.Add(CurrentDate)
            
            End If

         Next i
 
         ' Display the number of items selected.
         Message.Text = "Selection Count = " & _
             Calendar1.SelectedDates.Count.ToString()
 
      End Sub
 
      Sub Selection_Change(sender As Object, e As EventArgs) 

         ' Display the number of items selected.
         Message.Text = "Selection Count = " & _
             Calendar1.SelectedDates.Count.ToString()

      End Sub
 
   </script>
 
</head>     
<body>
 
   <form id="form1" runat="server">

      <h3>SelectedDatesCollection Add Example </h3>

      Click the button to select all Wednesdays in the month.

      <br /><br />
 
      <asp:Calendar ID="Calendar1" runat="server"  
           SelectionMode="DayWeekMonth" 
           OnSelectionChanged="Selection_Change" />
 
      <hr />
 
      <asp:Button id="SubmitButton"
           Text="Select All Weds in Month" 
           OnClick="Button_Click"  
           runat="server"  /> 

      <br />
 
      <asp:Label id="Message" 
           runat="server" />

   </form>

</body>
</html>

Remarks

Use this method to remove all System.DateTime objects from the SelectedDatesCollection collection and set the Count property to 0.

Applies to

See also