webform1.aspx
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="dynamicweb3_1.WebForm1" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Label ID="lblOutput" runat="server" Text="Label"></asp:Label>
</div>
</form>
</body>
</html>
webform1.aspx.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace dynamicweb3_1
{
public partial class WebForm1 : System.Web.UI.Page
{
//计算圆的面积：
const double PI = 3.1415926d;
double radius = 8.5;
double area = 0;
protected void Page_Load(object sender, EventArgs e)
{
area = radius * radius * PI;
lblOutput.Text = "圆的面积是：" + area.ToString();
}
}
}