public enum ENCODE_MODE
{
 ALPHA_NUMERIC,
 NUMERIC,
 BYTE
}

public enum ERROR_CORRECTION
{
 L,
 M,
 Q,
 H
}

public virtual Bitmap Encode(string content, Encoding encoding)
{
 bool[][] flagArray = this.calQrcode(encoding.GetBytes(content));
 SolidBrush brush = new SolidBrush(this.qrCodeBackgroundColor);
 Bitmap image = new Bitmap((flagArray.Length * this.qrCodeScale) + 1, (flagArray.Length * this.qrCodeScale) + 1);
 Graphics graphics = Graphics.FromImage(image);
 graphics.FillRectangle(brush, new Rectangle(0, 0, image.Width, image.Height));
 brush.Color = this.qrCodeForegroundColor;
 for (int i = 0; i < flagArray.Length; i++)
 {
  for (int j = 0; j < flagArray.Length; j++)
  {
   if (flagArray[j][i])
   {
    graphics.FillRectangle(brush, j * this.qrCodeScale, i * this.qrCodeScale, this.qrCodeScale, this.qrCodeScale);
   }
  }
 }
 return image;
}

 public virtual string decode(QRCodeImage qrCodeImage, Encoding encoding)
{
 sbyte[] src = this.decodeBytes(qrCodeImage);
 byte[] dst = new byte[src.Length];
 Buffer.BlockCopy(src, 0, dst, 0, dst.Length);
 return encoding.GetString(dst);
}

 
public virtual sbyte[] decodeBytes(QRCodeImage qrCodeImage)
{
 DecodeResult result;
 Point[] adjustPoints = this.AdjustPoints;
 ArrayList list = ArrayList.Synchronized(new ArrayList(10));
 while (this.numTryDecode < adjustPoints.Length)
 {
  try
  {
   result = this.decode(qrCodeImage, adjustPoints[this.numTryDecode]);
   if (result.CorrectionSucceeded)
   {
    return result.DecodedBytes;
   }
   list.Add(result);
   canvas.println("Decoding succeeded but could not correct");
   canvas.println("all errors. Retrying..");
  }
  catch (DecodingFailedException exception)
  {
   if (exception.Message.IndexOf("Finder Pattern") >= 0)
   {
    throw exception;
   }
  }
  finally
  {
   this.numTryDecode++;
  }
 }
 if (list.Count == 0)
 {
  throw new DecodingFailedException("Give up decoding");
 }
 int num = -1;
 int numErrors = 0x7fffffff;
 for (int i = 0; i < list.Count; i++)
 {
  result = (DecodeResult) list[i];
  if (result.NumErrors < numErrors)
  {
   numErrors = result.NumErrors;
   num = i;
  }
 }
 canvas.println("All trials need for correct error");
 canvas.println("Reporting #" + num + " that,");
 canvas.println("corrected minimum errors (" + numErrors + ")");
 canvas.println("Decoding finished.");
 return ((DecodeResult) list[num]).DecodedBytes;
}

 public class QRCodeBitmapImage : QRCodeImage
{
 // Fields
 private Bitmap image;

 // Methods
 public QRCodeBitmapImage(Bitmap image);
 public virtual int getPixel(int x, int y);

 // Properties
 public virtual int Height { get; }
 public virtual int Width { get; }
}

public interface QRCodeImage
{
 // Methods
 int getPixel(int x, int y);

 // Properties
 int Height { get; }
 int Width { get; }
}

 /// <summary>
  /// 生成二维码
  /// </summary>
  /// <param name="content">带生成二维码的字符串</param>
  /// <param name="path">路径</param>
  /// <returns></returns>
  public static string CreatehoughtWorksQrCode(string content, string path)
  {
   if (string.IsNullOrEmpty(content))
   {
    throw new ArgumentNullException(content);
   }
   if (string.IsNullOrEmpty(path))
   {
    throw new ArgumentNullException(path);
   }
   var qrCodeEncoder = new QRCodeEncoder
   {
    QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.BYTE,
    QRCodeScale = 4,
    QRCodeVersion = 8,
    QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.M
   };
   Image image = qrCodeEncoder.Encode(content);
   var filename = DateTime.Now.ToString("yyyymmddhhmmssfff") + ".jpg";
   var filepath = string.Format("{0}{1}", path, filename);
   FileStream fs = null;
   try
   {
    fs = new FileStream(filepath, FileMode.OpenOrCreate, FileAccess.Write);
    image.Save(fs, System.Drawing.Imaging.ImageFormat.Jpeg);
   }
   catch (IOException ex)
   {
    throw new IOException(ex.Message);
   }
   finally
   {
    if (fs != null) fs.Close();
    image.Dispose();
   }
   return CodeDecoder(filepath);
  }

 /// <summary>
  /// 选择生成二维码的相关类型
  /// <param name="strData">要生成的文字或者数字，支持中文。如： "4408810820 深圳－广州" 或者：4444444444</param>
  /// <param name="qrEncoding">三种尺寸：BYTE ，ALPHA_NUMERIC，NUMERIC</param>
  /// <param name="level">大小：L M Q H</param>
  /// <param name="version">版本：如 8</param>
  /// <param name="scale">比例：如 4</param>
  /// <returns></returns>
  /// </summary>
  public void CreateCode_Choose(string strData, string qrEncoding, string level, int version, int scale)
  {
   if (string.IsNullOrEmpty(strData))
   {
    throw new ArgumentNullException(strData);
   }
   if (string.IsNullOrEmpty(qrEncoding))
   {
    throw new ArgumentNullException(qrEncoding);
   }
   if (string.IsNullOrEmpty(level))
   {
    throw new ArgumentNullException(level);
   }
   var qrCodeEncoder = new QRCodeEncoder();
   var encoding = qrEncoding;
   switch (encoding)
   {
    case "Byte":
     qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.BYTE;
     break;
    case "AlphaNumeric":
     qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.ALPHA_NUMERIC;
     break;
    case "Numeric":
     qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.NUMERIC;
     break;
    default:
     qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.BYTE;
     break;
   }
   qrCodeEncoder.QRCodeScale = scale;
   qrCodeEncoder.QRCodeVersion = version;
   switch (level)
   {
    case "L":
     qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.L;
     break;
    case "M":
     qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.M;
     break;
    case "Q":
     qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.Q;
     break;
    default:
     qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.H;
     break;
   }
   Image image = null;
   FileStream fs = null;
   try
   {
    //文字生成图片
    image = qrCodeEncoder.Encode(strData);
    var filename = DateTime.Now.ToString("yyyymmddhhmmssfff") + ".jpg";
    var filepath = HttpContext.Current.Server.MapPath(@"~\Upload") + "\\" + filename;
    fs = new FileStream(filepath, FileMode.OpenOrCreate, FileAccess.Write);
    image.Save(fs, System.Drawing.Imaging.ImageFormat.Jpeg);
   }
   catch (IOException ioex)
   {
    throw new IOException(ioex.Message);
   }
   catch (Exception ex)
   {
    throw new Exception(ex.Message);
   }
   finally
   {
    if (fs != null) fs.Close();
    if (image != null) image.Dispose();
   }
  }

/// <summary>
  /// 二维码解码
  /// </summary>
  /// <param name="filePath">图片路径</param>
  /// <returns></returns>
  public static string CodeDecoder(string filePath)
  {
   if (string.IsNullOrEmpty(filePath))
   {
    throw new ArgumentNullException(filePath);
   }
   try
   {
    if (!File.Exists(filePath))
     return null;
    var myBitmap = new Bitmap(Image.FromFile(filePath));
    var decoder = new QRCodeDecoder();
    var decodedString = decoder.decode(new QRCodeBitmapImage(myBitmap));
    return decodedString;
   }
   catch (Exception ex)
   {
    throw new Exception(ex.Message);
   }
  }