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[ASP.net教程]随机生成6位图片验证码


/// <summary>  /// PicHandler1 的摘要说明  /// </summary>  public class PicHandler1 : IHttpHandler, IRequiresSessionState  {    private string mCheckNo = string.Empty;    protected ImgBuilder _ImgBuilder = new ImgBuilder();    protected VryImgGen _ImgBuilderNew = new VryImgGen();    private string _text = string.Empty;    private string _font = "宋体";    private int _fontSize = 8;    private int _padding = 2;    public void ProcessRequest(HttpContext context)    {      mCheckNo = DisCheckNo();      context.Session["CheckCode"] = mCheckNo;      this._ImgBuilder.FontSize = this._fontSize;      this._ImgBuilder.Padding = this._padding;       if (!string.IsNullOrEmpty(this._font))      {        this._ImgBuilder.Fonts = new string[] { this._font };      }      this._ImgBuilderNew.ChaosWight = 40;      this._ImgBuilderNew.FontSize = 25;       this._ImgBuilderNew.Padding = 3;      System.Drawing.Bitmap image =       this._ImgBuilderNew.CreateImage(mCheckNo);      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.ToArray());      context.Session["CheckCode"] = mCheckNo.ToString(); //如果没有实现IRequiresSessionState,则这里会出错,也无法生成图片      context.Response.End();    }     //验证码生成    protected string DisCheckNo()    {      string hash = HashCode.GetNext();      string CheckNo = string.Empty;      Random rd = new Random(DateTime.Now.Millisecond);      for (int i = 0; i < 6; i++)      {        CheckNo += hash.Substring(rd.Next(1, hash.Length - 1), 1);      }      CheckNo = CheckNo.Replace("0", rd.Next(1, 9).ToString());      CheckNo = CheckNo.Replace("o", rd.Next(1, 9).ToString());      CheckNo = CheckNo.Replace("O", rd.Next(1, 9).ToString());      return CheckNo;    }     public bool IsReusable    {      get      {        return false;      }    }  }

  

调用的类

 

using System;using System.Drawing;using System.Text; /// <summary>/// VryImgGen 的摘要说明/// </summary>public class VryImgGen{  public static string ChineseChars = String.Empty;   /// <summary>  /// 英文与数字串  /// </summary>  protected static readonly string EnglishOrNumChars = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";   public VryImgGen()  {    rnd = new Random(unchecked((int)DateTime.Now.Ticks));  }   /// <summary>  /// 全局随机数生成器  /// </summary>  private Random rnd;   int length = 5;  /// <summary>  /// 验证码长度(默认6个验证码的长度)  /// </summary>  public int Length  {    get { return length; }    set { length = value; }  }   int fontSize = 20;  /// <summary>  /// 验证码字体大小(为了显示扭曲效果,默认30像素,可以自行修改)  /// </summary>  public int FontSize  {    get { return fontSize; }    set { fontSize = value; }  }   int padding = 4;  /// <summary>  /// 边框补(默认4像素)  /// </summary>  public int Padding  {    get { return padding; }    set { padding = value; }  }   bool chaos = true;  /// <summary>  /// 是否输出燥点(默认输出)  /// </summary>  public bool Chaos  {    get { return chaos; }    set { chaos = value; }  }   Color chaosColor = Color.LightGray;  /// <summary>  /// 输出燥点的颜色(默认灰色)  /// </summary>  public Color ChaosColor  {    get { return chaosColor; }    set { chaosColor = value; }  }   int chaosWight = 1;  /// <summary>  /// 输出燥点的浓度  /// </summary>  public int ChaosWight  {    get { return chaosWight; }    set { chaosWight = value; }  }   Color backgroundColor = Color.White;  /// <summary>  /// 自定义背景色(默认白色)  /// </summary>  public Color BackgroundColor  {    get { return backgroundColor; }    set { backgroundColor = value; }  }   Color[] colors = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple };  /// <summary>  /// 自定义随机颜色数组  /// </summary>  public Color[] Colors  {    get { return colors; }    set { colors = value; }  }   string[] fonts = { "Arial", "Georgia" };  /// <summary>  /// 自定义字体数组  /// </summary>  public string[] Fonts  {    get { return fonts; }    set { fonts = value; }  }   #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(Edit By 51aspx.com)  /// </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   /// <summary>  /// 生成校验码图片  /// </summary>  /// <param name="code">验证码</param>  /// <returns></returns>  public Bitmap CreateImage(string code)  {    int fSize = FontSize;    int fWidth = fSize + Padding;     int imageWidth = (int)(code.Length * fWidth) + 4 + Padding * 2;    int imageHeight = fSize * 2 + Padding * 2;     System.Drawing.Bitmap image = new System.Drawing.Bitmap(imageWidth - 10, imageHeight - 10);     Graphics g = Graphics.FromImage(image);     g.Clear(BackgroundColor);     //给背景添加随机生成的燥点    if (this.Chaos)    {       Pen pen = new Pen(ChaosColor, 0);      int c = ChaosWight * 10;       for (int i = 0; i < c; i++)      {        int x = rnd.Next(image.Width);        int y = rnd.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 = rnd.Next(Colors.Length - 1);      findex = rnd.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 By 51aspx.com)    image = TwistImage(image, true, 8, 4);     return image;  }   /// <summary>  /// 生成随机字符码  /// </summary>  /// <param name="codeLen">字符串长度</param>  /// <param name="zhCharsCount">中文字符数</param>  /// <returns></returns>  public string CreateVerifyCode(int codeLen, int zhCharsCount)  {    char[] chs = new char[codeLen];     int index;    for (int i = 0; i < zhCharsCount; i++)    {      index = rnd.Next(0, codeLen);      if (chs[index] == '\0')        chs[index] = CreateZhChar();      else        --i;    }    for (int i = 0; i < codeLen; i++)    {      if (chs[i] == '\0')        chs[i] = CreateEnOrNumChar();    }     return new string(chs, 0, chs.Length);  }   /// <summary>  /// 生成默认长度5的随机字符码  /// </summary>  /// <returns></returns>  public string CreateVerifyCode()  {    return CreateVerifyCode(Length, 0);  }   /// <summary>  /// 生成英文或数字字符  /// </summary>  /// <returns></returns>  protected char CreateEnOrNumChar()  {    return EnglishOrNumChars[rnd.Next(0, EnglishOrNumChars.Length)];  }   /// <summary>  /// 生成汉字字符  /// </summary>  /// <returns></returns>  protected char CreateZhChar()  {    //若提供了汉字集,查询汉字集选取汉字    if (ChineseChars.Length > 0)    {      return ChineseChars[rnd.Next(0, ChineseChars.Length)];    }    //若没有提供汉字集,则根据《GB2312简体中文编码表》编码规则构造汉字    else    {      byte[] bytes = new byte[2];       //第一个字节值在0xb0, 0xf7之间      bytes[0] = (byte)rnd.Next(0xb0, 0xf8);      //第二个字节值在0xa1, 0xfe之间      bytes[1] = (byte)rnd.Next(0xa1, 0xff);       //根据汉字编码的字节数组解码出中文汉字      string str1 = Encoding.GetEncoding("gb2312").GetString(bytes);       return str1[0];    }  } }