default.aspx里：包含点击图片更新的js代码
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default3.aspx.cs" Inherits="Default3" %> <!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:TextBox ID="TextBox1" runat="server"></asp:TextBox> <asp:Image ID="Image1" runat="server" ImageUrl="YZM.aspx" /> <asp:Button ID="Button1" runat="server" Text="Button" /> <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label> </div> </form> </body> </html> <script>//点击图片更新 var a = 0; document.getElementById("Image1").onclick = function () { this.setAttribute("src","yzm.aspx?id="+a); a++; } </script>
default.cs里：验证相同的按钮事件写在这里
using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; public partial class Default3 : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { Button1.Click += Button1_Click; } void Button1_Click(object sender, EventArgs e)//验证是否相同 { string t1 = TextBox1.Text; string t2 = Session["yzm"].ToString(); if (t1.ToUpper() == t2.ToUpper()) { Label1.Text = "验证成功"; } else { Label1.Text = "验证失败"; } } }
YZM.aspx.cs里：主要的绘制，生成写在这里
using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.Drawing; public partial class YZM : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { Bitmap img = new Bitmap(70, 30); Graphics g = Graphics.FromImage(img);//绘制 Random r = new Random(); List<Color> clist = new List<Color>();//设定颜色集合 clist.Add(Color.Yellow); clist.Add(Color.Black); clist.Add(Color.Blue); clist.Add(Color.Green); clist.Add(Color.Pink); clist.Add(Color.Orange); for (int i = 0; i < 10; i++) { Color cl = clist[r.Next(0, clist.Count)];//随机选取颜色 Pen pe = new Pen(new SolidBrush(cl),r.Next(1,5));//随机生成颜色,随机生成线的粗细 g.DrawLine(pe, new PointF(r.Next(0, 70), r.Next(0, 30)), new PointF(r.Next(0, 70), r.Next(0, 30)));//随机生成线 } string all = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";//设定验证码集合 string s = ""; for (int i = 0; i < 4; i++)//随机生成四位验证码 { s += all.Substring(r.Next(1,all.Length),1); } Session["yzm"] = s;//设置全局变量，用于验证调用 g.DrawString(s, new Font("微软雅黑", 15), new SolidBrush(Color.Red), new PointF(5, 5));//绘制验证码 img.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Png);//输出流
response.end(); } }