We will look at four different ways to detect page load event in asp.net
4 ways to detect page load in
asp.net.
In this article, we are going to look into fourdifferent ways to detect page load in asp.net application. Sometimes, it
is very important to detect page load and in page load event there might few
important things to do.
For example, you want to show a
welcome or alert message when user will visit in your particular page. In this
situation we have to detect page Load event to prompt user.
Among those four techniques first
three techniques are client side technique means using Java script or JQuery we
will detect page load event and in last example we will see how to use c# to do
same. Let’s see one by one.
1) Window.onload
property
Window object has onload property
and by checking this property we can detect page load in JavaScript. Example
code is in below.
<%@
Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm6.aspx.cs" Inherits="ASP.NET.WebForm6"
%>
<!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></title>
<script>
window.onload = function () {
alert("welcome");
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
</div>
</form>
</body>
</html>
2) Detecting
onLoad() event of <BODY>
We know HTML pages has two section one is head and
other is body. And body has one event called OnLoad(). By checking this onLoad()
event we can detect when HTML body is getting load. In below code there is one function in body onLoad() event
<%@
Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm6.aspx.cs" Inherits="ASP.NET.WebForm6"
%>
<!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></title>
<script>
function CallLoad() {
alert("Body OnLoad function");
}
</script>
</head>
<body onload="CallLoad()">
<form id="form1" runat="server">
<div>
</div>
</form>
</body>
</html>

3)
Using
JQuery function
We can call document.ready() function of JQuery library and
within this function we can write code for body load event.
Don’t forget to include JQuery
CDN or local file before use JQuery.
<%@
Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm6.aspx.cs" Inherits="ASP.NET.WebForm6"
%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<head runat="server">
<script src="http://code.jquery.com/jquery-1.9.1.js"></script>
<script>
$(document).ready(function () {
alert("Using Jquery");
});
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
</div>
</form>
</body>
</html>

4) Using
C# pageLoad() event
This is server side technique to detect page load in
asp.net application. If we write something in Page_Load() event of C# code
behind then it will execute at time of page load.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace ASP.NET
{
public partial class WebForm6 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
Response.Write("Page Load event");
}
}
}

Conclusion:
We discussed four techniques to detect page load in
asp.net application. If you have different idea please share with us.