借助一般处理程序做验证码

 

 

Class1.cs的代码

#region 验证码长度(默认6个验证码的长度)
 int length = 6;
 public int Length
 {
 get { return length; }
 set { length = value; }
 }
 #endregion

 #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)
 int fontSize = 25;
 public int FontSize
 {
 get { return fontSize; }
 set { fontSize = value; }
 }
 #endregion

 #region 边框补(默认1像素)
 int padding = 2;
 public int Padding
 {
 get { return padding; }
 set { padding = value; }
 }
 #endregion

 #region 是否输出燥点(默认不输出)
 bool chaos = true;
 public bool Chaos
 {
 get { return chaos; }
 set { chaos = value; }
 }
 #endregion

 #region 输出燥点的颜色(默认灰色)
 Color chaosColor = Color.LightGray;
 public Color ChaosColor
 {
 get { return chaosColor; }
 set { chaosColor = value; }
 }
 #endregion

 #region 自定义背景色(默认白色)
 Color backgroundColor = Color.White;
 public Color BackgroundColor
 {
 get { return backgroundColor; }
 set { backgroundColor = value; }
 }
 #endregion

 #region 自定义随机颜色数组
 Color[] colors = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple };
 public Color[] Colors
 {
 get { return colors; }
 set { colors = value; }
 }
 #endregion

 #region 自定义字体数组
 string[] fonts = { "Arial", "Georgia" };
 public string[] Fonts
 {
 get { return fonts; }
 set { fonts = value; }
 }
 #endregion

 #region 自定义随机码字符串序列(使用逗号分隔)
 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";
 public string CodeSerial
 {
 get { return codeSerial; }
 set { codeSerial = value; }
 }
 #endregion

 #region 产生波形滤镜效果

 private const double PI = 3.1415926535897932384626433832795;
 private const double PI2 = 6.283185307179586476925286766559;

 /// <summary>
 /// 正弦曲线Wave扭曲图片（Edi）
 /// </summary>
 /// <param name="srcBmp">图片路径</param>
 /// <param name="bXDir">如果扭曲则选择为True</param>
 /// <param name="nMultValue">波形的幅度倍数，越大扭曲的程度越高，一般为3</param>
 /// <param name="dPhase">波形的起始相位，取值区间[0-2*PI)</param>
 /// <returns></returns>
 public System.Drawing.Bitmap TwistImage(Bitmap srcBmp, bool bXDir, double dMultValue, double dPhase)
 {
 System.Drawing.Bitmap destBmp = new Bitmap(srcBmp.Width, srcBmp.Height);

 // 将位图背景填充为白色
 System.Drawing.Graphics graph = System.Drawing.Graphics.FromImage(destBmp);
 graph.FillRectangle(new SolidBrush(System.Drawing.Color.White), 0, 0, destBmp.Width, destBmp.Height);
 graph.Dispose();

 double dBaseAxisLen = bXDir ? (double)destBmp.Height : (double)destBmp.Width;

 for (int i = 0; i < destBmp.Width; i++)
 {
 for (int j = 0; j < destBmp.Height; j++)
 {
 double dx = 0;
 dx = bXDir ? (PI2 * (double)j) / dBaseAxisLen : (PI2 * (double)i) / dBaseAxisLen;
 dx += dPhase;
 double dy = Math.Sin(dx);

 // 取得当前点的颜色
 int nOldX = 0, nOldY = 0;
 nOldX = bXDir ? i + (int)(dy * dMultValue) : i;
 nOldY = bXDir ? j : j + (int)(dy * dMultValue);

 System.Drawing.Color color = srcBmp.GetPixel(i, j);
 if (nOldX >= 0 && nOldX < destBmp.Width
 && nOldY >= 0 && nOldY < destBmp.Height)
 {
 destBmp.SetPixel(nOldX, nOldY, color);
 }
 }
 }

 return destBmp;
 }
 #endregion

 #region 生成校验码图片
 public Bitmap CreateImageCode(string code)
 {
 int fSize = FontSize;
 int fWidth = fSize + Padding;

 int imageWidth = (int)(code.Length * fWidth) + 4 + Padding * 2;
 int imageHeight = fSize * 2 + Padding;

 System.Drawing.Bitmap image = new System.Drawing.Bitmap(imageWidth, imageHeight);

 Graphics g = Graphics.FromImage(image);

 g.Clear(BackgroundColor);

 Random rand = new Random();

 //给背景添加随机生成的燥点
 if (this.Chaos)
 {

 Pen pen = new Pen(ChaosColor, 0);
 int c = Length * 10;

 for (int i = 0; i < c; i++)
 {
 int x = rand.Next(image.Width);
 int y = rand.Next(image.Height);

 g.DrawRectangle(pen, x, y, 1, 1);
 }
 }

 int left = 0, top = 0, top1 = 1, top2 = 1;

 int n1 = (imageHeight - FontSize - Padding * 2);
 int n2 = n1 / 4;
 top1 = n2;
 top2 = n2 * 2;

 Font f;
 Brush b;

 int cindex, findex;

 //随机字体和颜色的验证码字符
 for (int i = 0; i < code.Length; i++)
 {
 cindex = rand.Next(Colors.Length - 1);
 findex = rand.Next(Fonts.Length - 1);

 f = new System.Drawing.Font(Fonts[findex], fSize, System.Drawing.FontStyle.Bold);
 b = new System.Drawing.SolidBrush(Colors[cindex]);

 if (i % 2 == 1)
 {
 top = top2;
 }
 else
 {
 top = top1;
 }

 left = i * fWidth;

 g.DrawString(code.Substring(i, 1), f, b, left, top);
 }

 //画一个边框 边框颜色为Color.Gainsboro
 g.DrawRectangle(new Pen(Color.Gainsboro, 0), 0, 0, image.Width - 1, image.Height - 1);
 g.Dispose();

 //产生波形（Add ）
 image = TwistImage(image, true, 0, 0);

 return image;
 }
 #endregion

 #region 将创建好的图片输出到页面
 public Image CreateImageOnPage(string code)
 {
 System.IO.MemoryStream ms = new System.IO.MemoryStream();
 Bitmap image = this.CreateImageCode(code);
 return image;
 }
 #endregion

 #region 生成随机字符码
 public string CreateVerifyCode(int codeLen)
 {
 if (codeLen == 0)
 {
 codeLen = Length;
 }

 string[] arr = CodeSerial.Split(',');

 string code = "";

 int randValue = -1;

 Random rand = new Random(unchecked((int)DateTime.Now.Ticks));

 for (int i = 0; i < codeLen; i++)
 {
 randValue = rand.Next(0, arr.Length - 1);

 code += arr[randValue];
 }

 return code;
 }


 public string CreateVerifyCode()
 {
 return CreateVerifyCode(0);
 }
 #endregion



一般处理程序的代码


using System;
using System.Web;

public class Handler : IHttpHandler, System.Web.SessionState.IRequiresSessionState
{
 
 public void ProcessRequest (HttpContext context) {
 //建立验证码对象
 Class1 verifyCode = new Class1();
 //取随机码
 string code = verifyCode.CreateVerifyCode().Substring(0, 4);
 //将随机码放入Session
 context.Session["code"] = code.ToLower();
 //绘制验证码图片
 System.Drawing.Image image = verifyCode.CreateImageCode(code);

 //输出图片
 System.IO.MemoryStream ms = new System.IO.MemoryStream();
 image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
 context.Response.ClearContent();
 context.Response.ContentType = "image/Jpeg";
 context.Response.BinaryWrite(ms.GetBuffer());
 ms.Close();
 ms = null;
 image.Dispose();
 image = null;
 }

 public bool IsReusable {
 get {
 return false;
 }
 }

页面

<img id="imgshowcode" src="Handler.ashx?n=23564 " onclick="javascript:showcode();"
 alt="" height="20px" style="width: 70px; vertical-align: middle;" />

用到的JS

function createXMLHttpRequest() {
 if (window.XMLHttpRequest) {
 xmlReq = new XMLHttpRequest();
 if (xmlReq.overrideMimeType)
 xmlReq.overrideMimeType('text/xml');
 }
 else if (window.ActiveXObject) {
 try {
 xmlReq = new ActiveXObject('Msxml2.XMLHTTP');
 }
 catch (e) {
 try {
 xmlReq = new ActiveXObject('Microsoft.XMLHTTP');
 }
 catch (e) {

 }
 }
 }
 }

 var num;
 function showcode() {
 createXMLHttpRequest();

 num = Math.random();
 num = Math.round(num * 10000000);
 var url = 'Handler.ashx?t=' + num;

 xmlReq.open("GET", url, false);
 xmlReq.send(null);

 var img = document.getElementById("imgshowcode");
 img.src = 'Handler.ashx?t=' + num;

 }