前端添加的标签和方法：
验证码：
复制代码 代码如下:
<input type="text" maxlength="5"/> <img src="" alt="点击刷新" />  点击图片刷新</p>//标签
$(function () { $("#imgValidateCode").click(function () { DoFresh(); }); DoFresh(); }) function DoFresh() { var img = $("#imgValidateCode"); img.attr("src", "VerifyCode.aspx?random=" + Math.random()); } //添加的方法，src是生成图片的aspx的地址
然后在项目中在新建一个VerifyCode.aspx，下面是aspx的代码：
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="VerifyCode.aspx.cs" Inherits="Form.VerifyCode" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title></title> </head> <body> <form runat="server"> <div> </div> </form> </body> </html>
接着是aspx.cs的代码：
using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.Drawing; namespace Form { public partial class VerifyCode : System.Web.UI.Page { public static string HZ; /// <summary> /// 验证码的最大长度 /// </summary> public int MaxLength { get { return 10; } } /// <summary> /// 验证码的最小长度 /// </summary> public int MinLength { get { return 1; } } protected void Page_Load(object sender, EventArgs e) { string[] str = CreateValidateNumber(4); string strcode = string.Empty; for (int i = 0; i < str.Length; i++) { strcode += str[i]; } CreateCheckCodeImage(str); HZ = strcode; Response.Write(HZ); //验证码存入session Session["ValidateCode"] = HZ; } /// <summary> /// 生成验证码 /// </summary> /// <param>指定验证码的长度</param> /// <returns>验证码</returns> public string[] CreateValidateNumber(int length) { string Vchar = "1,2,3,4,5,6,7,8,9,a,b,c,d,e,f,g,h,i,j,k,l,m,n,p" + ",q,r,s,t,u,v,w,x,y,z,A,B,C,D,E,F,G,H,I,J,K,L,M,N,P,Q" + ",R,S,T,U,V,W,X,Y,Z"; string[] VcArray = Vchar.Split(new Char[] { ',' });//拆分成数组 string[] num = new string[length]; int temp = -1;//记录上次随机数值，尽量避避免生产几个一样的随机数 Random rand = new Random(); //采用一个简单的算法以保证生成随机数的不同 for (int i = 1; i < length + 1; i++) { if (temp != -1) { rand = new Random(i * temp * unchecked((int)DateTime.Now.Ticks)); } int t = rand.Next(VcArray.Length-1); if (temp != -1 && temp == t) { return CreateValidateNumber(length); } temp = t; num[i - 1] = VcArray[t]; //num.SetValue(VcArray[t]); //VNum += VcArray[t]; } return num; } private void CreateCheckCodeImage(string[] checkCode) { if (checkCode == null || checkCode.Length <= 0) return; System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length * 32.5)), 60); System.Drawing.Graphics g = Graphics.FromImage(image); try { //生成随机生成器 Random random = new Random(); //清空图片背景色 g.Clear(Color.White); //定义颜色 Color[] c = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple }; //画图片的背景噪音线 for (int i = 0; i < 25; i++) { int cindex = random.Next(7); int findex = random.Next(5); int x1 = random.Next(image.Width); int x2 = random.Next(image.Width); int y1 = random.Next(image.Height); int y2 = random.Next(image.Height); // g.DrawLine(new Pen(c[cindex]), x1, y1, x2, y2); } //定义字体 string[] f = { "Verdana", "Microsoft Sans Serif", "Comic Sans MS", "Arial", "宋体" }; for (int k = 0; k <= checkCode.Length - 1; k++) { int cindex = random.Next(7); int findex = random.Next(5); Font drawFont = new Font(f[findex], 26, (System.Drawing.FontStyle.Bold)); SolidBrush drawBrush = new SolidBrush(c[cindex]); float x = 5.0F; float y = 0.0F; float width = 42.0F; float height = 48.0F; int sjx = random.Next(10); int sjy = random.Next(image.Height - (int)height); RectangleF drawRect = new RectangleF(x + sjx + (k * 25), y + sjy, width, height); StringFormat drawFormat = new StringFormat(); drawFormat.Alignment = StringAlignment.Center; g.DrawString(checkCode[k], drawFont, drawBrush, drawRect, drawFormat); } //画图片的前景噪音点 for (int i = 0; i < 500; i++) { int x = random.Next(image.Width); int y = random.Next(image.Height); image.SetPixel(x, y, Color.FromArgb(random.Next())); } int cindex1 = random.Next(7); //画图片的边框线 g.DrawRectangle(new Pen(c[cindex1]), 0, 0, image.Width - 1, image.Height - 1); System.IO.MemoryStream ms = new System.IO.MemoryStream(); image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif); Response.ClearContent(); Response.ContentType = "image/Gif"; Response.BinaryWrite(ms.ToArray()); } finally { g.Dispose(); image.Dispose(); } } } }
于是！就可以生成验证码了，然后自己再把编写验证版的判断逻辑写好就可以啦！