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12306動(dòng)態(tài)驗(yàn)證碼啟發(fā)之ASP.NET實(shí)現(xiàn)動(dòng)態(tài)GIF驗(yàn)證碼(附源碼)

更新時(shí)間：2022年05月03日 12:26:32 投稿：lijiao

這篇文章主要介紹了受到12306動(dòng)態(tài)驗(yàn)證碼啟發(fā)，實(shí)現(xiàn)ASP.NET動(dòng)態(tài)GIF驗(yàn)證碼,需要的朋友可以參考下

12306網(wǎng)站推出“彩色動(dòng)態(tài)驗(yàn)證碼機(jī)制”，新版驗(yàn)證碼不但經(jīng)常出現(xiàn)字符疊壓，還不停抖動(dòng)，不少人大呼“看不清”，稱“那個(gè)驗(yàn)證碼，是畢加索的抽象畫么!”鐵總客服則表示:為了能正常購(gòu)票只能這樣。而多家搶票軟件接近“報(bào)廢”，引發(fā)不少網(wǎng)友不滿的吐槽稱“太抽象太藝術(shù)了”。
以前做項(xiàng)目有時(shí)候也會(huì)用到驗(yàn)證碼，但基本都是靜態(tài)的，這次也想湊湊12306的熱鬧。閑言少續(xù)，切入正題，先上代碼。

實(shí)現(xiàn)方法：

public void ShowCode()
    {
      //對(duì)象實(shí)例化
      Validate GifValidate = new Validate();

      #region 對(duì)驗(yàn)證碼進(jìn)行設(shè)置(不進(jìn)行設(shè)置時(shí),將以默認(rèn)值生成)
      //驗(yàn)證碼位數(shù)，不小于4位
      GifValidate.ValidateCodeCount = 4;
      //驗(yàn)證碼字體型號(hào)(默認(rèn)13)
      GifValidate.ValidateCodeSize = 13;
      //驗(yàn)證碼圖片高度,高度越大,字符的上下偏移量就越明顯
      GifValidate.ImageHeight = 23;
      //驗(yàn)證碼字符及線條顏色(需要參考顏色類)
      GifValidate.DrawColor = System.Drawing.Color.BlueViolet;
      //驗(yàn)證碼字體(需要填寫服務(wù)器安裝的字體)
      GifValidate.ValidateCodeFont = "Arial";
      //驗(yàn)證碼字符是否消除鋸齒
      GifValidate.FontTextRenderingHint = false;
      //定義驗(yàn)證碼中所有的字符(","分離),似乎暫時(shí)不支持中文
      GifValidate.AllChar = "1,2,3,4,5,6,7,8,9,0,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";
      #endregion

      //輸出圖像(Session名稱)
      GifValidate.OutPutValidate("GetCode");
    }

調(diào)用主要方法：

public class Validate
  {
    public string AllChar = "1,2,3,4,5,6,7,8,9,0,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";
    public Color DrawColor = Color.BlueViolet;
    public bool FontTextRenderingHint = false;
    public int ImageHeight = 0x17;
    private byte TrueValidateCodeCount = 4;
    protected string ValidateCode = "";
    public string ValidateCodeFont = "Arial";
    public float ValidateCodeSize = 13f;

    private void CreateImageBmp(out Bitmap ImageFrame)
    {
      char[] chArray = this.ValidateCode.ToCharArray(0, this.ValidateCodeCount);
      int width = (int) (((this.TrueValidateCodeCount * this.ValidateCodeSize) * 1.3) + 4.0);
      ImageFrame = new Bitmap(width, this.ImageHeight);
      Graphics graphics = Graphics.FromImage(ImageFrame);
      graphics.Clear(Color.White);
      Font font = new Font(this.ValidateCodeFont, this.ValidateCodeSize, FontStyle.Bold);
      Brush brush = new SolidBrush(this.DrawColor);
      int maxValue = (int) Math.Max((float) ((this.ImageHeight - this.ValidateCodeSize) - 3f), (float) 2f);
      Random random = new Random();
      for (int i = 0; i < this.TrueValidateCodeCount; i++)
      {
        int[] numArray = new int[] { (((int) (i * this.ValidateCodeSize)) + random.Next(1)) + 3, random.Next(maxValue) };
        Point point = new Point(numArray[0], numArray[1]);
        if (this.FontTextRenderingHint)
        {
          graphics.TextRenderingHint = TextRenderingHint.SingleBitPerPixel;
        }
        else
        {
          graphics.TextRenderingHint = TextRenderingHint.AntiAlias;
        }
        graphics.DrawString(chArray[i].ToString(), font, brush, (PointF) point);
      }
      graphics.Dispose();
    }

    private void CreateImageGif()
    {
      AnimatedGifEncoder encoder = new AnimatedGifEncoder();
      MemoryStream stream = new MemoryStream();
      encoder.Start();
      encoder.SetDelay(5);
      encoder.SetRepeat(0);
      for (int i = 0; i < 10; i++)
      {
        Bitmap bitmap;
        this.CreateImageBmp(out bitmap);
        this.DisposeImageBmp(ref bitmap);
        bitmap.Save(stream, ImageFormat.Png);
        encoder.AddFrame(Image.FromStream(stream));
        stream = new MemoryStream();
      }
      encoder.OutPut(ref stream);
      HttpContext.Current.Response.ClearContent();
      HttpContext.Current.Response.ContentType = "image/Gif";
      HttpContext.Current.Response.BinaryWrite(stream.ToArray());
      stream.Close();
      stream.Dispose();
    }

    private void CreateValidate()
    {
      this.ValidateCode = "";
      string[] strArray = this.AllChar.Split(new char[] { ',' });
      int index = -1;
      Random random = new Random();
      for (int i = 0; i < this.ValidateCodeCount; i++)
      {
        if (index != -1)
        {
          random = new Random((i * index) * ((int) DateTime.Now.Ticks));
        }
        int num3 = random.Next(0x23);
        if (index == num3)
        {
          this.CreateValidate();
        }
        index = num3;
        this.ValidateCode = this.ValidateCode + strArray[index];
      }
      if (this.ValidateCode.Length > this.TrueValidateCodeCount)
      {
        this.ValidateCode = this.ValidateCode.Remove(this.TrueValidateCodeCount);
      }
    }

    private void DisposeImageBmp(ref Bitmap ImageFrame)
    {
      Graphics graphics = Graphics.FromImage(ImageFrame);
      Pen pen = new Pen(this.DrawColor, 1f);
      Random random = new Random();
      Point[] pointArray = new Point[2];
      for (int i = 0; i < 15; i++)
      {
        pointArray[0] = new Point(random.Next(ImageFrame.Width), random.Next(ImageFrame.Height));
        pointArray[1] = new Point(random.Next(ImageFrame.Width), random.Next(ImageFrame.Height));
        graphics.DrawLine(pen, pointArray[0], pointArray[1]);
      }
      graphics.Dispose();
    }

    public void OutPutValidate(string ValidateCodeSession)
    {
      this.CreateValidate();
      this.CreateImageGif();
      HttpContext.Current.Session[ValidateCodeSession] = this.ValidateCode;
    }

    public byte ValidateCodeCount
    {
      get
      {
        return this.TrueValidateCodeCount;
      }
      set
      {
        if (value > 4)
        {
          this.TrueValidateCodeCount = value;
        }
      }
    }
  }

驗(yàn)證碼效果： -----下載源碼-----