本着简洁直接，我们就直奔主题吧！
下面是一个生成数字和字母随机组合的验证码类源代码：
using System; using System.Drawing; using System.Drawing.Imaging; using System.Web.UI; using System.Drawing.Drawing2D; using System.IO; namespace Forcheng.Code { /// <summary> /// 生成验证码的类 /// </summary> public class ValidateCode { /// <summary> /// 生成验证码 /// </summary> /// <param name="length">指定验证码的长度</param> /// <returns></returns> public string CreateValidateCode(int length) { const string validateTemplate = "23456789abcdefghijkmnopqrstuvwxyzABCDEFGHIJKLMNPQRSTUVWXYZ"; string validateStr = ""; int n = validateTemplate.Length - 1; //设置随机值生成器 int seekSeek = unchecked((int)DateTime.Now.Ticks); Random seekRand = new Random(seekSeek); int beginSeek = 0; //生成随机验证码 for (int i = 0; i < length; i++) { beginSeek = seekRand.Next(0, n); validateStr += validateTemplate.Substring(beginSeek, 1); } return validateStr; } /// <summary> /// 创建验证码的图片 /// </summary> /// <param name="containsPage">要输出到的page对象</param> /// <param name="validateNum">验证码</param> public byte[] CreateValidateGraphic(string validateCode) { Bitmap image = new Bitmap((int)Math.Ceiling(validateCode.Length * 13.0), 22); 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); //画图片的干扰线 for (int i = 0; i < 25; i++) { 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(Color.Silver), x1, y1, x2, y2); } Font font = new Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic)); LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true); g.DrawString(validateCode, font, brush, 3, 2); //画图片的前景干扰点 for (int i = 0; i < 100; i++) { int x = random.Next(image.Width); int y = random.Next(image.Height); image.SetPixel(x, y, Color.FromArgb(random.Next())); } //画图片的边框线 g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1); //保存图片数据 MemoryStream stream = new MemoryStream(); image.Save(stream, ImageFormat.Jpeg); //输出图片流 return stream.ToArray(); } finally { g.Dispose(); image.Dispose(); } } } }
下面是使用验证码类的后台实例代码（生成一个5位的图片验证码）：
using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Mvc; using System.Web.Security; using Forcheng.Code; namespace Test.Controllers { public class HomeController : Controller { /// <summary> /// 获取图片验证码 /// </summary> /// <returns></returns> public ActionResult GetValidateCode(string codeClass) { ValidateCode vCode = new ValidateCode(); string code = vCode.CreateValidateCode(5); byte[] bytes = vCode.CreateValidateGraphic(code); return File(bytes, @"image/jpeg"); } } }
下面是前台页面使用的实例代码：
<!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>图片验证码</title> </head> <body> <img id="valiCode" class="validcode" src="/Home/GetValidateCode" alt="验证码" title="点击刷新" /> <script type="text/javascript"> $(document).ready(function () { $("#valiCode").bind("click", function () { this.src = "/Home/GetValidateCode?&time=" + (new Date()).getTime(); }); }); </script> </body> </html>
效果截图（做的另一个找回密码页面，不是上面的前台代码效果）：
这次的分享就到这吧，我们下次继续。
<我的博客主页>:http://www.cnblogs.com/forcheng/