生成图片的帮助类
using System; using System.Drawing; using System.Drawing.Drawing2D; using System.Drawing.Imaging; using System.IO; namespace WebApplication1.Controllers { public class ValidateCode { public ValidateCode() { } /// <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; } } /// <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) { int[] randMembers = new int[length]; int[] validateNums = new int[length]; string validateNumberStr = ""; //生成起始序列值 int seekSeek = unchecked((int)DateTime.Now.Ticks); Random seekRand = new Random(seekSeek); int beginSeek = (int)seekRand.Next(0, Int32.MaxValue - length * 10000); int[] seeks = new int[length]; for (int i = 0; i < length; i++) { beginSeek += 10000; seeks[i] = beginSeek; } //生成随机数字 for (int i = 0; i < length; i++) { Random rand = new Random(seeks[i]); int pownum = 1 * (int)Math.Pow(10, length); randMembers[i] = rand.Next(pownum, Int32.MaxValue); } //抽取随机数字 for (int i = 0; i < length; i++) { string numStr = randMembers[i].ToString(); int numLength = numStr.Length; Random rand = new Random(); int numPosition = rand.Next(0, numLength - 1); validateNums[i] = Int32.Parse(numStr.Substring(numPosition, 1)); } //生成验证码 for (int i = 0; i < length; i++) { validateNumberStr += validateNums[i].ToString(); } return validateNumberStr; } //C# MVC 升级版 /// <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 * 12.0), 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(); } } /// <summary> /// 得到验证码图片的长度 /// </summary> /// <param name="validateNumLength">验证码的长度</param> /// <returns></returns> public static int GetImageWidth(int validateNumLength) { return (int)(validateNumLength * 12.0); } /// <summary> /// 得到验证码的高度 /// </summary> /// <returns></returns> public static double GetImageHeight() { return 22.5; } } }
控制器的写法 (控制器名称LoginController)
using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Mvc; namespace WebApplication1.Controllers { public class LoginController : Controller { // GET: Login public ActionResult Index() { return View(); } /// <summary> /// 验证码的校验 /// </summary> /// <param name="context"></param> /// <returns></returns> public ActionResult CheckCode() { //生成验证码 ValidateCode validateCode = new ValidateCode(); string code = validateCode.CreateValidateCode(4); Session["ValidateCode"] = code; byte[] bytes = validateCode.CreateValidateGraphic(code); return File(bytes, @"image/jpeg"); } /// <summary> /// 验证验证码是否正确 /// </summary> /// <param name="num"></param> /// <returns></returns> public bool CheckValidateCode(string num) { string cnum = Session["ValidateCode"] == null ? "" : Session["ValidateCode"].ToString(); if (num == cnum && !string.IsNullOrEmpty(num)) { return true; } else { return false; } } /// <summary> /// 登录页面 /// </summary> /// <returns></returns> public ActionResult Login() { return View(); } /// <summary> /// 登录验证方法 /// </summary> /// <param name="Info">info为存用户的实体,把用户信息与验证信息一起提交到这个方法里</param> /// <returns></returns> [HttpPost] public ActionResult Login(UserInfo Info) { ///Info.Str前段传入的验证字符串用CheckValidateCode()进行验证 if (!CheckValidateCode(Info.Str)) { return Content("<script>javascript:alert(‘验证码输入不正确‘);location.href=‘/Login/Login‘;</script>"); } ///写个假的用户信息 if (Info.UserName=="张三"&&Info.PassWord=="111") { return Content("<script>javascript:alert(‘登录成功‘);location.href=‘/Login/Index‘;</script>"); } else { return Content("<script>javascript:alert(‘登录失败‘);location.href=‘/Login/Login‘;</script>"); } } } }
前段MVC的写法
@{ ViewBag.Title = "Login"; } <h2>Login</h2> <script> function ClickRemoveChangeCode() { var code = $("#imgCode").attr("src"); $("#imgCode").attr("src", code + "1"); } </script> @using (Html.BeginForm("Login", "Login", "post")) { <table class="table active"> <tr> <td> 用户名 </td> <td> <input type="text" name="UserName" value="" /> </td> </tr> <tr> <td> 密码 </td> <td> <input type="text" name="PassWord" value="" /> </td> </tr> <tr> <td> 验证码 </td> <td> <input type="text" name="Str" value="" /> </td> </tr> <tr> <td>验证码：</td> <td> <img src="/Login/CheckCode?ID=1" id="imgCode" alt="单击可刷新" onclick="ClickRemoveChangeCode()" /> <div style="float:right; margin-top: 5px;"> <a href="javascript:void(0)" onclick="ClickRemoveChangeCode();return false;">看不清，换一张</a> </div> </td> </tr> <tr> <td colspan="2"> <input type="submit" value="登录" /> </td> </tr> </table> }