目前，网站为了防止用户利用机器人自动注册，登录，灌水，都采用验证码技术。本文验证码由数学组合成4位验证码。详细代
码如下
新建一个页面test.aspx，代码如下

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="test.aspx.cs" Inherits="macrozhou_test" %>

验证码:

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class macrozhou_test : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
Random rnd = new Random();
Label1.Text = rnd.Next(1000, 9999).ToString();
Label2.Text = Label1.Text;
}
}
protected void Button1_Click(object sender, EventArgs e)
{
if (this.TextBox1.Text.Trim() == this.Label1.Text.Trim())
{
//Response.Redirect(“/index.aspx”);
this.Label1.Text = “ok”;
}
else
{
//Response.Redirect(“/error.aspx”);
this.Label1.Text = “no”;
}
}
}
以上代码通过测试。