Calendar.OnPreRender(EventArgs) Method

Reference

Definition

Namespace:: System.Web.UI.WebControls

Assembly:: System.Web.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Raises the PreRender event.

protected:
 override void OnPreRender(EventArgs ^ e);

protected public:
 override void OnPreRender(EventArgs ^ e);

protected override void OnPreRender (EventArgs e);

protected internal override void OnPreRender (EventArgs e);

override this.OnPreRender : EventArgs -> unit

Protected Overrides Sub OnPreRender (e As EventArgs)

Protected Friend Overrides Sub OnPreRender (e As EventArgs)

Parameters

e: EventArgs

An EventArgs that contains event data.

Examples

The following code example demonstrates how to override the OnPreRender method so that it always displays a three-point border in a custom Calendar server control.

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %>
<%@ Page language="c#" %>
<!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>Custom Calendar - OnPreRender - C# Example</title>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">
      <h3>Custom Calendar - OnPreRender - C# Example</h3>

      <aspSample:CustomCalendarOnPreRender
        id="Calendar1"
        runat="server" />

    </form>
  </body>
</html>

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB" %>
<%@ Page language="VB" %>
<!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>Custom Calendar - OnPreRender - VB.NET Example</title>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">
      <h3>Custom Calendar - OnPreRender - VB.NET Example</h3>
      <aspSample:CustomCalendarOnPreRender id="Calendar1" runat="server" />
    </form>
  </body>
</html>

using System.Web;
using System.Security.Permissions;

namespace Samples.AspNet.CS.Controls
{
    [AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
    public sealed class CustomCalendarOnPreRender : System.Web.UI.WebControls.Calendar
    {
        protected override void OnPreRender(System.EventArgs e)
        {
            // Run the OnPreRender method on the base class.
            base.OnPreRender(e);

            // Display the Calendar with a 3 point border.
            this.BorderWidth =  System.Web.UI.WebControls.Unit.Point(3);
        }
    }
}

Imports System.Web
Imports System.Security.Permissions

Namespace Samples.AspNet.VB.Controls
    <AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
    Public NotInheritable Class CustomCalendarOnPreRender
        Inherits System.Web.UI.WebControls.Calendar

        Protected Overrides Sub OnPreRender(ByVal e As System.EventArgs)
            ' Run the OnPreRender method on the base class.
            MyBase.OnPreRender(e)

            ' Display the Calendar with a 3 point border.
            Me.BorderWidth = System.Web.UI.WebControls.Unit.Point(3)
        End Sub
    End Class
End Namespace

Remarks

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

The OnPreRender 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 OnPreRender(EventArgs) in a derived class, be sure to call the base class's OnPreRender(EventArgs) method so that registered delegates receive the event.

Applies to

Del via