ASP.netMVC验证码

1、复制下列代码，拷贝到控制器中。 #region ?生成验证码图片 ???????// [OutputCache(Location = OutputCacheLocation.None, Duration = 0, NoStore = false)] ???????public ActionResult SecurityCode() ???????{ ???????????string oldcode = Session["SecurityCode"] as string; ???????????string code = CreateRandomCode(5); ???????????Session["SecurityCode"] = code; ???????????return File(CreateValidateGraphic(code), "image/Jpeg"); ???????} ???????private byte[] CreateImage(string checkCode) ???????{ ???????????int iwidth = (int)(checkCode.Length * 12); ???????????System.Drawing.Bitmap image = new System.Drawing.Bitmap(iwidth, 20); ???????????Graphics g = Graphics.FromImage(image); ???????????Font f = new System.Drawing.Font("Arial", 10, System.Drawing.FontStyle.Bold); ???????????Brush b = new System.Drawing.SolidBrush(Color.White); ???????????g.Clear(Color.Blue); ???????????g.DrawString(checkCode, f, b, 3, 3); ???????????Pen blackPen = new Pen(Color.Black, 0); ???????????Random rand = new Random(); ???????????for (int i = 0; i < 5; i++) ???????????{ ???????????????int x1 = rand.Next(image.Width); ???????????????int x2 = rand.Next(image.Width); ???????????????int y1 = rand.Next(image.Height); ???????????????int y2 = rand.Next(image.Height); ???????????????g.DrawLine(new Pen(Color.Silver, 1), x1, y1, x2, y2); ???????????} ???????????System.IO.MemoryStream ms = new System.IO.MemoryStream(); ???????????image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg); ???????????return ms.ToArray(); ???????} ???????private string CreateRandomCode(int codeCount) ???????{ ???????????string allChar = "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,W,X,Y,Z"; ???????????string[] allCharArray = allChar.Split(‘,‘); ???????????string randomCode = ""; ???????????int temp = -1; ???????????Random rand = new Random(); ???????????for (int i = 0; i < codeCount; i++) ???????????{ ???????????????if (temp != -1) ???????????????{ ???????????????????rand = new Random(i * temp * ((int)DateTime.Now.Ticks)); ???????????????} ???????????????int t = rand.Next(35); ???????????????if (temp == t) ???????????????{ ???????????????????return CreateRandomCode(codeCount); ???????????????} ???????????????temp = t; ???????????????randomCode += allCharArray[t]; ???????????} ???????????return randomCode; ???????} ???????/// <summary> ???????/// 创建验证码的图片 ???????/// </summary> ???????public byte[] CreateValidateGraphic(string validateCode) ???????{ ???????????Bitmap image = new Bitmap((int)Math.Ceiling(validateCode.Length * 16.0), 27); ???????????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", 13, (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(); ???????????} ???????} ???????#endregion2、复制以下图片标记到视图中 ???<img src="/控制器的名字/SecurityCode" onclick="this.src+=‘?new Date()‘" />3、验证方式，使用 Session["SecurityCode"] 判断填写的是否相等。