Answer:
Default.aspx
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="WebApplication5.WebForm1" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
</head>
<body>
<form id="form1" runat="server">
<div>
<h2>Perfect Number Checker</h2>
<label for="Label1">Enter a number:</label>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox><br />
<asp:Button ID="Button1" runat="server" Text="Check" OnClick="btnCheck_Click" /><br />
<asp:Label ID="Label2" runat="server" ForeColor="Red"></asp:Label>
</div>
</form>
</body>
</html>Default.aspx.cs
using System;
using System.Web.UI;
namespace WebApplication5
{
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void btnCheck_Click(object sender, EventArgs e)
{
try
{
int number = int.Parse(TextBox1.Text);
if (IsPerfectNumber(number))
{
Label2.Text = number + " is a perfect number!";
}
else
{
throw new Exception(number + " is a not perfect number!");
}
}
catch (Exception ex)
{
Label2.Text = ex.Message;
}
}
private bool IsPerfectNumber(int number)
{
if (number <= 0)
return false;
int sum = 0;
for (int i = 1; i <= number / 2; i++)
{
if (number % i == 0)
{
sum += i;
}
}
return sum == number;
}
}
}