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asp.net中的比较完美的验证码

原作者: [db:作者] 来自: [db:来源] 收藏 邀请

本文转载:http://blog.csdn.net/zjk20108023/article/details/7836174

 

要实现如图的效果的验证码,分以下步骤:

第一、布局好调用验证码的登录页面(命名:Login.aspx),注意:验证码位置可以是服务器控件 Image,也可以是html标签写的<img>,但是图片url就是一个页面(命名:ValidateCode.aspx)(将在下面讲述。)比如:<asp:Image ID=“vcImg”      ImageUrl="~/ValidateCode.aspx"   runat="server" />

第二、生成类文件 (命名:validatedCode)

 

  1. using System; 
  2. using System.Data; 
  3. using System.Configuration; 
  4. using System.Linq; 
  5. using System.Web; 
  6. using System.Web.Security; 
  7. using System.Web.UI; 
  8. using System.Web.UI.HtmlControls; 
  9. using System.Web.UI.WebControls; 
  10. using System.Web.UI.WebControls.WebParts; 
  11. using System.Xml.Linq; 
  12. using System.Drawing; 
  13. using System.IO; 
  14. using System.Drawing.Imaging; 
  15.  
  16. /// <summary> 
  17. /// Summary description for validatedCode 
  18. /// </summary> 
  19. public class validatedCode 
  20. {    
  21.        #region  验证码长度(默认6个验证码的长度) 
  22.         int length = 4; 
  23.         public int Length 
  24.         { 
  25.             get { return length; } 
  26.             set { length = value; } 
  27.         } 
  28.         #endregion 
  29.         #region 验证码字体大小(为了显示扭曲效果,默认40像素,可以自行修改) 
  30.         int fontSize = 40; 
  31.         public int FontSize 
  32.         { 
  33.             get { return fontSize; } 
  34.             set { fontSize = value; } 
  35.         } 
  36.         #endregion 
  37.         #region 边框补(默认1像素) 
  38.         int padding = 2; 
  39.         public int Padding 
  40.         { 
  41.             get { return padding; } 
  42.             set { padding = value; } 
  43.         } 
  44.         #endregion 
  45.         #region 是否输出燥点(默认不输出) 
  46.         bool chaos = true
  47.         public bool Chaos 
  48.         { 
  49.             get { return chaos; } 
  50.             set { chaos = value; } 
  51.         } 
  52.         #endregion 
  53.         #region 输出燥点的颜色(默认灰色) 
  54.         Color chaosColor = Color.LightGray; 
  55.         public Color ChaosColor 
  56.         { 
  57.             get { return chaosColor; } 
  58.             set { chaosColor = value; } 
  59.         } 
  60.         #endregion 
  61.         #region 自定义背景色(默认白色) 
  62.         Color backgroundColor = Color.White; 
  63.         public Color BackgroundColor 
  64.         { 
  65.             get { return backgroundColor; } 
  66.             set { backgroundColor = value; } 
  67.         } 
  68.         #endregion 
  69.         #region 自定义随机颜色数组 
  70.         Color[] colors = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple }; 
  71.         public Color[] Colors 
  72.         { 
  73.             get { return colors; } 
  74.             set { colors = value; } 
  75.         } 
  76.         #endregion 
  77.         #region 自定义字体数组 
  78.         string[] fonts = { "Arial", "Georgia" }; 
  79.         public string[] Fonts 
  80.         { 
  81.             get { return fonts; } 
  82.             set { fonts = value; } 
  83.         } 
  84.         #endregion 
  85.         #region 自定义随机码字符串序列(使用逗号分隔) 
  86.         string codeSerial = "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,v,w,x,y,z,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z"
  87.         public string CodeSerial 
  88.         { 
  89.             get { return codeSerial; } 
  90.             set { codeSerial = value; } 
  91.         } 
  92.         #endregion 
  93.         #region 产生波形滤镜效果 
  94.  
  95.         private const double PI = 3.1415926535897932384626433832795; 
  96.         private const double PI2 = 6.283185307179586476925286766559; 
  97.  
  98.         /// <summary> 
  99.         /// 正弦曲线Wave扭曲图片(Edit By 51aspx.com) 
  100.         /// </summary> 
  101.         /// <param name="srcBmp">图片路径</param> 
  102.         /// <param name="bXDir">如果扭曲则选择为True</param> 
  103.         /// <param name="nMultValue">波形的幅度倍数,越大扭曲的程度越高,一般为3</param> 
  104.         /// <param name="dPhase">波形的起始相位,取值区间[0-2*PI)</param> 
  105.         /// <returns></returns> 
  106.         public System.Drawing.Bitmap TwistImage(Bitmap srcBmp, bool bXDir, double dMultValue, double dPhase) 
  107.         { 
  108.             System.Drawing.Bitmap destBmp = new Bitmap(srcBmp.Width, srcBmp.Height); 
  109.  
  110.             // 将位图背景填充为白色 
  111.             System.Drawing.Graphics graph = System.Drawing.Graphics.FromImage(destBmp); 
  112.             graph.FillRectangle(new SolidBrush(System.Drawing.Color.White), 0, 0, destBmp.Width, destBmp.Height); 
  113.             graph.Dispose(); 
  114.  
  115.             double dBaseAxisLen = bXDir ? (double)destBmp.Height : (double)destBmp.Width; 
  116.  
  117.             for (int i = 0; i < destBmp.Width; i++) 
  118.             { 
  119.                 for (int j = 0; j < destBmp.Height; j++) 
  120.                 { 
  121.                     double dx = 0; 
  122.                     dx = bXDir ? (PI2 * (double)j) / dBaseAxisLen : (PI2 * (double)i) / dBaseAxisLen; 
  123.                     dx += dPhase; 
  124.                     double dy = Math.Sin(dx); 
  125.  
  126.                     // 取得当前点的颜色 
  127.                     int nOldX = 0, nOldY = 0; 
  128.                     nOldX = bXDir ? i + (int)(dy * dMultValue) : i; 
  129.                     nOldY = bXDir ? j : j + (int)(dy * dMultValue); 
  130.  
  131.                     System.Drawing.Color color = srcBmp.GetPixel(i, j); 
  132.                     if (nOldX >= 0 && nOldX < destBmp.Width 
  133.                      && nOldY >= 0 && nOldY < destBmp.Height) 
  134.                     { 
  135.                         destBmp.SetPixel(nOldX, nOldY, color); 
  136.                     } 
  137.                 } 
  138.             } 
  139.  
  140.             return destBmp; 
  141.         } 
  142.         #endregion 
  143.         #region 生成校验码图片 
  144.         public Bitmap CreateImageCode(string code) 
  145.         { 
  146.             int fSize = FontSize; 
  147.             int fWidth = fSize + Padding; 
  148.  
  149.             int imageWidth = (int)(code.Length * fWidth) + 4 + Padding * 2; 
  150.             int imageHeight = fSize * 2 + Padding; 
  151.  
  152.             System.Drawing.Bitmap image = new System.Drawing.Bitmap(imageWidth, imageHeight); 
  153.  
  154.             Graphics g = Graphics.FromImage(image); 
  155.  
  156.             g.Clear(BackgroundColor); 
  157.  
  158.             Random rand = new Random(); 
  159.  
  160.             //给背景添加随机生成的燥点 
  161.             if (this.Chaos) 
  162.             { 
  163.  
  164.                 Pen pen = new Pen(ChaosColor, 0); 
  165.                 int c = Length * 10; 
  166.  
  167.                 for (int i = 0; i < c; i++) 
  168.                 { 
  169.                     int x = rand.Next(image.Width); 
  170.                     int y = rand.Next(image.Height); 
  171.  
  172.                     g.DrawRectangle(pen, x, y, 1, 1); 
  173.                 } 
  174.             } 
  175.  
  176.             int left = 0, top = 0, top1 = 1, top2 = 1; 
  177.  
  178.             int n1 = (imageHeight - FontSize - Padding * 2); 
  179.             int n2 = n1 / 4; 
  180.             top1 = n2; 
  181.             top2 = n2 * 2; 
  182.  
  183.             Font f; 
  184.             Brush b; 
  185.  
  186.             int cindex, findex; 
  187.  
  188.             //随机字体和颜色的验证码字符 
  189.             for (int i = 0; i < code.Length; i++) 
  190.             { 
  191.                 cindex = rand.Next(Colors.Length - 1); 
  192.                 findex = rand.Next(Fonts.Length - 1); 
  193.  
  194.                 f = new System.Drawing.Font(Fonts[findex], fSize, System.Drawing.FontStyle.Bold); 
  195.                 b = new System.Drawing.SolidBrush(Colors[cindex]); 
  196.  
  197.                 if (i % 2 == 1) 
  198.                 { 
  199.                     top = top2; 
  200.                 } 
  201.                 else 
  202.                 { 
  203.                     top = top1; 
  204.                 } 
  205.  
  206.                 left = i * fWidth; 
  207.  
  208.                 g.DrawString(code.Substring(i, 1), f, b, left, top); 
  209.             } 
  210.  
  211.             //画一个边框 边框颜色为Color.Gainsboro 
  212.             g.DrawRectangle(new Pen(Color.Gainsboro, 0), 0, 0, image.Width - 1, image.Height - 1); 
  213.             g.Dispose(); 
  214.  
  215.             //产生波形(Add By 51aspx.com) 
  216.             image = TwistImage(image, true, 8, 4); 
  217.  
  218.             return image; 
  219.         } 
  220.         #endregion 
  221.         #region 将创建好的图片输出到页面 
  222.         public void CreateImageOnPage(string code, HttpContext context) 
  223.         { 
  224.             System.IO.MemoryStream ms = new System.IO.MemoryStream(); 
  225.             Bitmap image = this.CreateImageCode(code); 
  226.  
  227.             image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg); 
  228.  
  229.             context.Response.ClearContent(); 
  230.             context.Response.ContentType = "image/Jpeg"
  231.             context.Response.BinaryWrite(ms.GetBuffer()); 
  232.  
  233.             ms.Close(); 
  234.             ms = null
  235.             image.Dispose(); 
  236.             image = null
  237.         } 
  238.         #endregion 
  239.         #region 生成随机字符码 
  240.         public string CreateVerifyCode(int codeLen) 
  241.         { 
  242.             if (codeLen == 0) 
  243.             { 
  244.                 codeLen = Length; 
  245.             } 
  246.  
  247.             string[] arr = CodeSerial.Split(','); 
  248.  
  249.             string code = ""
  250.  
  251.             int randValue = -1; 
  252.  
  253.             Random rand = new Random(unchecked((int)DateTime.Now.Ticks)); 
  254.  
  255.             for (int i = 0; i < codeLen; i++) 
  256.             { 
  257.                 randValue = rand.Next(0, arr.Length - 1); 
  258.  
  259.                 code += arr[randValue]; 
  260.             } 
  261.  
  262.             return code; 
  263.         } 
  264.         public string CreateVerifyCode() 
  265.         { 
  266.             return CreateVerifyCode(0); 
  267.         } 
  268.         #endregion 
PS:虽然不是我自己写的,但是可分享给大家。

 

代码中有注释,所以我就不多说了。

第三、生成调用类文件的网页(ValidateCode.aspx),在该页面的后台代码(ValidateCode.aspx.cs文件)的Page_Load事件中写如下代码:

 

  1. protected void Page_Load(object sender, EventArgs e) 
  2.     validatedCode v = new validatedCode(); 
  3.     string code = v.CreateVerifyCode();            //取随机码 
  4.     v.CreateImageOnPage(code, this.Context);       // 输出图片 
  5.     Session["CheckCode"] = code;                   //Session 取出验证码 
第四、判断验证结果:Login.aspx页面的登录事件中添加验证

 

 

  1. protected void btnLogin_Click(object sender, EventArgs e) 
  2.    { 
  3.        string vCode = Session["CheckCode"].ToString(); 
  4.        if (txtValidatedcode.Text.Trim().ToUpper() == vCode.ToUpper()) 
  5.        { 
  6.            ScriptManager.RegisterStartupScript(this.Page, this.GetType(), "Startup", "alert('ValidatedCode is right!');", true); 
  7.        } 
  8.    } 

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