界面：
1 <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default2.aspx.cs" Inherits="Default2" %> 2 3 <!DOCTYPE html> 4 5 <html xmlns="http://www.w3.org/1999/xhtml"> 6 <head runat="server"> 7 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 8 <title></title> 9 </head> 10 <body> 11 <form id="form1" runat="server"> 12 <div> 13 <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox> 14 <asp:Image ID="Image1" runat="server" ImageUrl="YZM.aspx" /> 15 <asp:Button ID="Button1" runat="server" Text="验证" /> 16 <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label> 17 </div> 18 </form> 19 </body> 20 </html> 21 <script type="text/javascript"> 22 var a = 0; 23 //点击图片更换验证码 24 document.getElementById("Image1").onclick = function () { 25 this.setAttribute("src", "yzm.aspx?id=" + a); 26 a++; 27 } 28 </script>
后台：
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Web; 5 using System.Web.UI; 6 using System.Web.UI.WebControls; 7 8 public partial class Default2 : System.Web.UI.Page 9 { 10 protected void Page_Load(object sender, EventArgs e) 11 { 12 Button1.Click += Button1_Click; 13 } 14 15 void Button1_Click(object sender, EventArgs e) 16 { 17 string t1 = TextBox1.Text; 18 string t2 = Session["YZM"].ToString(); 19 20 if (t1.ToUpper() == t2.ToUpper()) 21 { 22 Label1.Text = "验证成功！"; 23 } 24 else 25 { 26 Label1.Text = "验证失败！"; 27 } 28 29 30 } 31 }
验证码制作：
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Web; 5 using System.Web.UI; 6 using System.Web.UI.WebControls; 7 using System.Drawing; 8 9 public partial class YZM : System.Web.UI.Page 10 { 11 protected void Page_Load(object sender, EventArgs e) 12 { 13 Bitmap img = new Bitmap(80, 40);//验证码图片大小 14 Graphics g = Graphics.FromImage(img); 15 Random r = new Random(); 16 //背景色 17 List<Color> clist = new List<Color>(); 18 clist.Add(Color.Yellow); 19 clist.Add(Color.Green); 20 clist.Add(Color.Blue); 21 clist.Add(Color.Pink); 22 clist.Add(Color.Orange); 23 clist.Add(Color.AliceBlue); 24 clist.Add(Color.Aqua); 25 clist.Add(Color.Cyan); 26 clist.Add(Color.DarkOliveGreen); 27 clist.Add(Color.Black); 28 29 g.FillRectangle(new SolidBrush(clist[r.Next(0, clist.Count)]), 0, 0, 80, 40); 30 31 32 33 for (int i = 0; i < 10; i++) 34 { 35 Color ccc = clist[r.Next(0, clist.Count)];//随机颜色 36 37 Pen ppp = new Pen(new SolidBrush(ccc), r.Next(1, 5));//随机线条 38 39 g.DrawLine(ppp, new PointF(r.Next(0, 80), r.Next(0, 40)), new PointF(r.Next(0, 80), r.Next(0, 40))); 40 } 41 42 43 44 45 //验证码 46 string all = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; 47 string s = ""; 48 49 for (int i = 0; i < 4; i++) 50 { 51 int a = r.Next(all.Length);//随机取数 52 s += all.Substring(a, 1); 53 } 54 55 Session["YZM"] = s; 56 57 g.DrawString(s, new Font("微软雅黑", 16), new SolidBrush(Color.Red), new PointF(3, 3)); 58 59 img.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Png); 60 Response.End(); 61 62 } 63 }