MVC 验证码

验证码类

 public class VerifyCode

    {



      public  string checkCode = String.Empty;

        public byte[] BuildImg()

        {

            int number;

          

            System.Random random2 = new Random();

            for (int i = 0; i < 4; i++) //字符和数字的混合.长度为4。其实i的大小可以自由设置

            {

                number = random2.Next();

                checkCode += ((number % 2 == 0) ? (char)('0' + (char)(number % 10)) : (char)('A' + (char)(number % 26))).ToString();

            }

            System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length * 14.5)), 22);//用指定的大小初始化Bitmap类创建图像对象

            Graphics g = Graphics.FromImage(image);//表示在指定的图像上写字

            try

            {

                Random random = new Random();

                //清空图片背景色

                g.Clear(Color.White);

                //画图片的背景噪音线

                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);

                }//用银色笔在图像区域内划线形成背景噪音线

                Font font = new System.Drawing.Font("Arial", 14, (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Italic));//设置验证码的字体属性

                System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);

                //用画笔画出高级的2D向量图形字体

                g.DrawString(checkCode, font, brush, 2, 2);//以字符串的形式输出

                //画图片的前景噪音点

                for (int i = 0; i < 100; i++)//i的大小可以自由设置

                {

                    int x = random.Next(image.Width);

                    int y = random.Next(image.Height);



                    image.SetPixel(x, y, Color.FromArgb(random.Next()));

                } //随机设置图像的像素

                //画图片的边框线

                g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);

                //用银色笔画出边框线

                System.IO.MemoryStream ms = new System.IO.MemoryStream();//申明一个内存流对象

                image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);

                return ms.ToArray();

            }

            finally

            {

                g.Dispose();//释放绘图对象

                image.Dispose();//释放图像对象

            }

        }





    }

control

 

   public class VerifyCodeController : Controller

    {

        public FileContentResult Index()

        {

            VerifyCode v = new VerifyCode();        

            byte[] bytes =v.BuildImg();

            Session["vcode"] = v.checkCode;

            return File(bytes, @"image/jpeg");

        }

    }

 view

         <script>

        function fun()

        {

            $("#img")[0].src = $("#img")[0].src + "?" + Math.random;                       

        }



  

    </script>

              <img alt="验证码图片"  id="img" src="@Url.Action("Index","VerifyCode")" style="width: 100px; height: 38px; border: 1px solid #ddd; margin-bottom: -15px;"  />

                    <a href="#" onclick="fun()"  style="color: #1b66c7">换一张</a>