HtmlInputCheckBox.OnPreRender Method (EventArgs)
.NET Framework (current version)
Raises the OnPreRender event and registers the control as one that requires postback handling.
Assembly: System.Web (in System.Web.dll)
The OnPreRender method overrides the base OnPreRender method. OnPreRender is used primarily by control developers.
The following code example demonstrates how to override the OnPreRender method in a custom server control so that a Title attribute is added to each HtmlInputCheckBox control.
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %> <%@ 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>Custom HtmlInputCheckBox - OnPreRender - C# Example</title> <script runat="server"> void Button1_Click(Object sender, EventArgs e) { Div1.InnerHtml = ""; if(HtmlInputCheckBox1.Checked == true) { Div1.InnerHtml = "You like basketball. "; } if(HtmlInputCheckBox2.Checked == true) { Div1.InnerHtml += "You like football. "; } if(HtmlInputCheckBox3.Checked == true) { Div1.InnerHtml += "You like soccer. "; } } </script> </head> <body> <form id="Form1" method="post" runat="server"> <h3>Custom HtmlInputCheckBox - OnPreRender - C# Example</h3> <br /> Enter Interests:<p> <aspSample:CustomHtmlInputCheckBoxOnPreRender id="HtmlInputCheckBox1" runat="server" type="checkbox" checked value="Basketball"> Basketball <aspSample:CustomHtmlInputCheckBoxOnPreRender id="HtmlInputCheckBox2" runat="server" type="checkbox" value="Football"> Football <aspSample:CustomHtmlInputCheckBoxOnPreRender id="HtmlInputCheckBox3" runat="server" type="checkbox" value="Soccer"> Soccer </p> <p> <input id="Button1" runat="server" type="button" value="Enter" onserverclick="Button1_Click" name="Button1" /> </p> <div id="Div1" runat="server" style="DISPLAY: inline; WIDTH: 256px; HEIGHT: 15px" /> </form> </body> </html>
using System.Web; using System.Security.Permissions; namespace Samples.AspNet.CS.Controls { [AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)] public sealed class CustomHtmlInputCheckBoxOnPreRender : System.Web.UI.HtmlControls.HtmlInputCheckBox { protected override void OnPreRender(System.EventArgs e) { // Call the base class's OnPreRender method. base.OnPreRender(e); // Add a Title attribute to each HtmlInputCheckBox. this.Attributes.Add("title", "If you like " + this.Value + ", then select this check box."); } } }
.NET Framework
Available since 1.1
Available since 1.1
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