IAD Lab 2: ASP.NET Page Life Cycle

Problem Statement

Problem 1: Create a web application on Visual Studio using ASP.NET.
Problem 2: Demonstrate the ASP.NET page processing (life cycle events).

ASP.NET Code Implementation

Default.aspx

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default" %>

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Page Life Cycle Events</title>
</head>
<body>
    <form id="form1" runat="server">
        <div>
            <asp:Label runat="server" Text="Page Life Cycle Events" Font-Bold="True" />
            <br /><br />
            <asp:Button ID="btnTrigger" runat="server" Text="Click Me" />
            <br /><br />
            <asp:Label ID="Output" runat="server" Text="" />
        </div>
    </form>
</body>
</html>

Default.aspx.vb

Partial Class _Default
    Inherits System.Web.UI.Page

    Private Sub _Default_Init(sender As Object, e As EventArgs) Handles Me.Init
        Output.Text &= "1. Page Init Event<br/>"
    End Sub

    Private Sub _Default_Load(sender As Object, e As EventArgs) Handles Me.Load
        Output.Text &= "2. Page Load Event<br/>"
    End Sub

    Private Sub btnTrigger_Click(sender As Object, e As EventArgs) Handles btnTrigger.Click
        Output.Text &= "3. Button Click Event<br/>"
    End Sub

    Private Sub _Default_PreRender(sender As Object, e As EventArgs) Handles Me.PreRender
        Output.Text &= "4. Page PreRender Event<br/><br/>"
    End Sub

    Private Sub _Default_Unload(sender As Object, e As EventArgs) Handles Me.Unload
        ' Cannot update label - Used for Debugging Only
        Output.Text &= "5. Page Unload Event<br/>"
    End Sub
End Class

Demo & Output

Click the button below to view how ASP.NET processes page events in sequence:

Run Page Life Cycle Demo

Sample Outputs

Page rendering

Visual Studio Snapshot