internal static DecoderResult decode(byte[] bytes)
 {
    BitSource bits = new BitSource(bytes);
    StringBuilder result = new StringBuilder(100);
    StringBuilder resultTrailer = new StringBuilder(0);
    List<byte[]> byteSegments = new List<byte[]>(1);
    Mode mode = Mode.ASCII_ENCODE;
    do
    {
       if (mode == Mode.ASCII_ENCODE)
       {
          if (!decodeAsciiSegment(bits, result, resultTrailer, out mode))
             return null;
       }
       else
       {
          switch (mode)
          {
             case Mode.C40_ENCODE:
                if (!decodeC40Segment(bits, result))
                   return null;
                break;
             case Mode.TEXT_ENCODE:
                if (!decodeTextSegment(bits, result))
                   return null;
                break;
             case Mode.ANSIX12_ENCODE:
                if (!decodeAnsiX12Segment(bits, result))
                   return null;
                break;
             case Mode.EDIFACT_ENCODE:
                if (!decodeEdifactSegment(bits, result))
                   return null;
                break;
             case Mode.BASE256_ENCODE:
                if (!decodeBase256Segment(bits, result, byteSegments))
                   return null;
                break;
             default:
                return null;
          }
          mode = Mode.ASCII_ENCODE;
       }
    } while (mode != Mode.PAD_ENCODE && bits.available() > 0);
    if (resultTrailer.Length > 0)
    {
       result.Append(resultTrailer.ToString());
    }
    return new DecoderResult(bytes, result.ToString(), byteSegments.Count == 0 ? null : byteSegments, null);
 }
示例#2
0
        public void testSource()
        {
            byte[]    bytes  = { 1, 2, 3, 4, 5 };
            BitSource source = new BitSource(bytes);

            Assert.AreEqual(40, source.available());
            Assert.AreEqual(0, source.readBits(1));
            Assert.AreEqual(39, source.available());
            Assert.AreEqual(0, source.readBits(6));
            Assert.AreEqual(33, source.available());
            Assert.AreEqual(1, source.readBits(1));
            Assert.AreEqual(32, source.available());
            Assert.AreEqual(2, source.readBits(8));
            Assert.AreEqual(24, source.available());
            Assert.AreEqual(12, source.readBits(10));
            Assert.AreEqual(14, source.available());
            Assert.AreEqual(16, source.readBits(8));
            Assert.AreEqual(6, source.available());
            Assert.AreEqual(5, source.readBits(6));
            Assert.AreEqual(0, source.available());
        }
      /// <summary>
      /// See ISO 16022:2006, 5.2.8 and Annex C Table C.3
      /// </summary>
      private static bool decodeEdifactSegment(BitSource bits, StringBuilder result)
      {
         do
         {
            // If there is only two or less bytes left then it will be encoded as ASCII
            if (bits.available() <= 16)
            {
               return true;
            }

            for (int i = 0; i < 4; i++)
            {
               int edifactValue = bits.readBits(6);

               // Check for the unlatch character
               if (edifactValue == 0x1F)
               {  // 011111
                  // Read rest of byte, which should be 0, and stop
                  int bitsLeft = 8 - bits.BitOffset;
                  if (bitsLeft != 8)
                  {
                     bits.readBits(bitsLeft);
                  }
                  return true;
               }

               if ((edifactValue & 0x20) == 0)
               {  // no 1 in the leading (6th) bit
                  edifactValue |= 0x40;  // Add a leading 01 to the 6 bit binary value
               }
               result.Append((char)edifactValue);
            }
         } while (bits.available() > 0);

         return true;
      }
      /// <summary>
      /// See ISO 16022:2006, 5.2.7
      /// </summary>
      private static bool decodeAnsiX12Segment(BitSource bits,
                                               StringBuilder result)
      {
         // Three ANSI X12 values are encoded in a 16-bit value as
         // (1600 * C1) + (40 * C2) + C3 + 1

         int[] cValues = new int[3];
         do
         {
            // If there is only one byte left then it will be encoded as ASCII
            if (bits.available() == 8)
            {
               return true;
            }
            int firstByte = bits.readBits(8);
            if (firstByte == 254)
            {  // Unlatch codeword
               return true;
            }

            parseTwoBytes(firstByte, bits.readBits(8), cValues);

            for (int i = 0; i < 3; i++)
            {
               int cValue = cValues[i];
               if (cValue == 0)
               {  // X12 segment terminator <CR>
                  result.Append('\r');
               }
               else if (cValue == 1)
               {  // X12 segment separator *
                  result.Append('*');
               }
               else if (cValue == 2)
               {  // X12 sub-element separator >
                  result.Append('>');
               }
               else if (cValue == 3)
               {  // space
                  result.Append(' ');
               }
               else if (cValue < 14)
               {  // 0 - 9
                  result.Append((char)(cValue + 44));
               }
               else if (cValue < 40)
               {  // A - Z
                  result.Append((char)(cValue + 51));
               }
               else
               {
                  return false;
               }
            }
         } while (bits.available() > 0);

         return true;
      }
      /// <summary>
      /// See ISO 16022:2006, 5.2.6 and Annex C, Table C.2
      /// </summary>
      private static bool decodeTextSegment(BitSource bits, StringBuilder result)
      {
         // Three Text values are encoded in a 16-bit value as
         // (1600 * C1) + (40 * C2) + C3 + 1
         // TODO(bbrown): The Upper Shift with Text doesn't work in the 4 value scenario all the time
         bool upperShift = false;

         int[] cValues = new int[3];
         int shift = 0;
         do
         {
            // If there is only one byte left then it will be encoded as ASCII
            if (bits.available() == 8)
            {
               return true;
            }
            int firstByte = bits.readBits(8);
            if (firstByte == 254)
            {  
               // Unlatch codeword
               return true;
            }

            parseTwoBytes(firstByte, bits.readBits(8), cValues);

            for (int i = 0; i < 3; i++)
            {
               int cValue = cValues[i];
               switch (shift)
               {
                  case 0:
                     if (cValue < 3)
                     {
                        shift = cValue + 1;
                     }
                     else if (cValue < TEXT_BASIC_SET_CHARS.Length)
                     {
                        char textChar = TEXT_BASIC_SET_CHARS[cValue];
                        if (upperShift)
                        {
                           result.Append((char)(textChar + 128));
                           upperShift = false;
                        }
                        else
                        {
                           result.Append(textChar);
                        }
                     }
                     else
                     {
                        return false;
                     }
                     break;
                  case 1:
                     if (upperShift)
                     {
                        result.Append((char)(cValue + 128));
                        upperShift = false;
                     }
                     else
                     {
                        result.Append((char)cValue);
                     }
                     shift = 0;
                     break;
                  case 2:
                     // Shift 2 for Text is the same encoding as C40
                     if (cValue < C40_SHIFT2_SET_CHARS.Length)
                     {
                        char c40char = C40_SHIFT2_SET_CHARS[cValue];
                        if (upperShift)
                        {
                           result.Append((char)(c40char + 128));
                           upperShift = false;
                        }
                        else
                        {
                           result.Append(c40char);
                        }
                     }
                     else if (cValue == 27)
                     {  // FNC1
                        result.Append((char)29); // translate as ASCII 29
                     }
                     else if (cValue == 30)
                     {  // Upper Shift
                        upperShift = true;
                     }
                     else
                     {
                        return false;
                     }
                     shift = 0;
                     break;
                  case 3:
                     if (cValue < TEXT_SHIFT3_SET_CHARS.Length)
                     {
                        char textChar = TEXT_SHIFT3_SET_CHARS[cValue];
                        if (upperShift)
                        {
                           result.Append((char)(textChar + 128));
                           upperShift = false;
                        }
                        else
                        {
                           result.Append(textChar);
                        }
                        shift = 0;
                     }
                     else
                     {
                        return false;
                     }
                     break;
                  default:
                     return false;
               }
            }
         } while (bits.available() > 0);

         return true;
      }
 /// <summary>
 /// See ISO 16022:2006, 5.2.3 and Annex C, Table C.2
 /// </summary>
 private static bool decodeAsciiSegment(BitSource bits,
                                        StringBuilder result,
                                        StringBuilder resultTrailer,
                                        out Mode mode)
 {
    bool upperShift = false;
    mode = Mode.ASCII_ENCODE;
    do
    {
       int oneByte = bits.readBits(8);
       if (oneByte == 0)
       {
          return false;
       }
       else if (oneByte <= 128)
       {  // ASCII data (ASCII value + 1)
          if (upperShift)
          {
             oneByte += 128;
             //upperShift = false;
          }
          result.Append((char)(oneByte - 1));
          mode = Mode.ASCII_ENCODE;
          return true;
       }
       else if (oneByte == 129)
       {  // Pad
          mode = Mode.PAD_ENCODE;
          return true;
       }
       else if (oneByte <= 229)
       {  // 2-digit data 00-99 (Numeric Value + 130)
          int value = oneByte - 130;
          if (value < 10)
          { // padd with '0' for single digit values
             result.Append('0');
          }
          result.Append(value);
       }
       else if (oneByte == 230)
       {  // Latch to C40 encodation
          mode = Mode.C40_ENCODE;
          return true;
       }
       else if (oneByte == 231)
       {  // Latch to Base 256 encodation
          mode = Mode.BASE256_ENCODE;
          return true;
       }
       else if (oneByte == 232)
       {
          // FNC1
          result.Append((char)29); // translate as ASCII 29
       }
       else if (oneByte == 233 || oneByte == 234)
       {
          // Structured Append, Reader Programming
          // Ignore these symbols for now
          //throw ReaderException.Instance;
       }
       else if (oneByte == 235)
       {  // Upper Shift (shift to Extended ASCII)
          upperShift = true;
       }
       else if (oneByte == 236)
       {  // 05 Macro
          result.Append("[)>\u001E05\u001D");
          resultTrailer.Insert(0, "\u001E\u0004");
       }
       else if (oneByte == 237)
       {  // 06 Macro
          result.Append("[)>\u001E06\u001D");
          resultTrailer.Insert(0, "\u001E\u0004");
       }
       else if (oneByte == 238)
       {  // Latch to ANSI X12 encodation
          mode = Mode.ANSIX12_ENCODE;
          return true;
       }
       else if (oneByte == 239)
       {  // Latch to Text encodation
          mode = Mode.TEXT_ENCODE;
          return true;
       }
       else if (oneByte == 240)
       {  // Latch to EDIFACT encodation
          mode = Mode.EDIFACT_ENCODE;
          return true;
       }
       else if (oneByte == 241)
       {  // ECI Character
          // TODO(bbrown): I think we need to support ECI
          //throw ReaderException.Instance;
          // Ignore this symbol for now
       }
       else if (oneByte >= 242)
       {  // Not to be used in ASCII encodation
          // ... but work around encoders that end with 254, latch back to ASCII
          if (oneByte != 254 || bits.available() != 0)
          {
             return false;
          }
       }
    } while (bits.available() > 0);
    mode = Mode.ASCII_ENCODE;
    return true;
 }
 private static int parseECIValue(BitSource bits)
 {
    int firstByte = bits.readBits(8);
    if ((firstByte & 0x80) == 0)
    {
       // just one byte
       return firstByte & 0x7F;
    }
    if ((firstByte & 0xC0) == 0x80)
    {
       // two bytes
       int secondByte = bits.readBits(8);
       return ((firstByte & 0x3F) << 8) | secondByte;
    }
    if ((firstByte & 0xE0) == 0xC0)
    {
       // three bytes
       int secondThirdBytes = bits.readBits(16);
       return ((firstByte & 0x1F) << 16) | secondThirdBytes;
    }
    throw new ArgumentException("Bad ECI bits starting with byte " + firstByte);
 }
      private static bool decodeNumericSegment(BitSource bits,
                                               StringBuilder result,
                                               int count)
      {
         // Read three digits at a time
         while (count >= 3)
         {
            // Each 10 bits encodes three digits
            if (bits.available() < 10)
            {
               return false;
            }
            int threeDigitsBits = bits.readBits(10);
            if (threeDigitsBits >= 1000)
            {
               return false;
            }
            result.Append(toAlphaNumericChar(threeDigitsBits / 100));
            result.Append(toAlphaNumericChar((threeDigitsBits / 10) % 10));
            result.Append(toAlphaNumericChar(threeDigitsBits % 10));

            count -= 3;
         }
         if (count == 2)
         {
            // Two digits left over to read, encoded in 7 bits
            if (bits.available() < 7)
            {
               return false;
            }
            int twoDigitsBits = bits.readBits(7);
            if (twoDigitsBits >= 100)
            {
               return false;
            }
            result.Append(toAlphaNumericChar(twoDigitsBits / 10));
            result.Append(toAlphaNumericChar(twoDigitsBits % 10));
         }
         else if (count == 1)
         {
            // One digit left over to read
            if (bits.available() < 4)
            {
               return false;
            }
            int digitBits = bits.readBits(4);
            if (digitBits >= 10)
            {
               return false;
            }
            result.Append(toAlphaNumericChar(digitBits));
         }

         return true;
      }
示例#9
0
      private static bool decodeKanjiSegment(BitSource bits,
                                             StringBuilder result,
                                             int count)
      {
         // Don't crash trying to read more bits than we have available.
         if (count * 13 > bits.available())
         {
            return false;
         }

         // Each character will require 2 bytes. Read the characters as 2-byte pairs
         // and decode as Shift_JIS afterwards
         byte[] buffer = new byte[2 * count];
         int offset = 0;
         while (count > 0)
         {
            // Each 13 bits encodes a 2-byte character
            int twoBytes = bits.readBits(13);
            int assembledTwoBytes = ((twoBytes / 0x0C0) << 8) | (twoBytes % 0x0C0);
            if (assembledTwoBytes < 0x01F00)
            {
               // In the 0x8140 to 0x9FFC range
               assembledTwoBytes += 0x08140;
            }
            else
            {
               // In the 0xE040 to 0xEBBF range
               assembledTwoBytes += 0x0C140;
            }
            buffer[offset] = (byte)(assembledTwoBytes >> 8);
            buffer[offset + 1] = (byte)assembledTwoBytes;
            offset += 2;
            count--;
         }
         // Shift_JIS may not be supported in some environments:
         try
         {
            result.Append(Encoding.GetEncoding(StringUtils.SHIFT_JIS).GetString(buffer, 0, buffer.Length));
         }
         catch (Exception)
         {
            return false;
         }
         return true;
      }
      private static bool decodeAlphanumericSegment(BitSource bits,
                                                    StringBuilder result,
                                                    int count,
                                                    bool fc1InEffect)
      {
         // Read two characters at a time
         int start = result.Length;
         while (count > 1)
         {
            if (bits.available() < 11)
            {
               return false;
            }
            int nextTwoCharsBits = bits.readBits(11);
            result.Append(toAlphaNumericChar(nextTwoCharsBits / 45));
            result.Append(toAlphaNumericChar(nextTwoCharsBits % 45));
            count -= 2;
         }
         if (count == 1)
         {
            // special case: one character left
            if (bits.available() < 6)
            {
               return false;
            }
            result.Append(toAlphaNumericChar(bits.readBits(6)));
         }

         // See section 6.4.8.1, 6.4.8.2
         if (fc1InEffect)
         {
            // We need to massage the result a bit if in an FNC1 mode:
            for (int i = start; i < result.Length; i++)
            {
               if (result[i] == '%')
               {
                  if (i < result.Length - 1 && result[i + 1] == '%')
                  {
                     // %% is rendered as %
                     result.Remove(i + 1, 1);
                  }
                  else
                  {
                     // In alpha mode, % should be converted to FNC1 separator 0x1D
                     result.Remove(i, 1);
                     result.Insert(i, new[] { (char)0x1D });
                  }
               }
            }
         }

         return true;
      }
      private static bool decodeByteSegment(BitSource bits,
                                            StringBuilder result,
                                            int count,
                                            IList<byte[]> byteSegments,
                                            IDictionary<DecodeHintType, object> hints)
      {
         // Don't crash trying to read more bits than we have available.
         if (count << 3 > bits.available())
         {
            return false;
         }

         byte[] readBytes = new byte[count];
         for (int i = 0; i < count; i++)
         {
            readBytes[i] = (byte)bits.readBits(8);
         }
         String encoding;
         encoding = StringUtils.guessEncoding(readBytes, hints);
        
         try
         {
            result.Append(Encoding.GetEncoding(encoding).GetString(readBytes, 0, readBytes.Length));
         }
#if (WINDOWS_PHONE70 || WINDOWS_PHONE71 || SILVERLIGHT4 || SILVERLIGHT5 || NETFX_CORE || MONOANDROID || MONOTOUCH)
         catch (ArgumentException)
         {
            try
            {
               // Silverlight only supports a limited number of character sets, trying fallback to UTF-8
               result.Append(Encoding.GetEncoding("UTF-8").GetString(readBytes, 0, readBytes.Length));
            }
            catch (Exception)
            {
               return false;
            }
         }
#endif
#if WindowsCE
         catch (PlatformNotSupportedException)
         {
            try
            {
               // WindowsCE doesn't support all encodings. But it is device depended.
               // So we try here the some different ones
               if (encoding == "ISO-8859-1")
               {
                  result.Append(Encoding.GetEncoding(1252).GetString(readBytes, 0, readBytes.Length));
               }
               else
               {
                  result.Append(Encoding.GetEncoding("UTF-8").GetString(readBytes, 0, readBytes.Length));
               }
            }
            catch (Exception)
            {
               return false;
            }
         }
#endif
         catch (Exception)
         {
            return false;
         }
         byteSegments.Add(readBytes);

         return true;
      }
      private static bool decodeKanjiSegment(BitSource bits,
                                             StringBuilder result,
                                             int count)
      {
         // Don't crash trying to read more bits than we have available.
         if (count * 13 > bits.available())
         {
            return false;
         }

         // Each character will require 2 bytes. Read the characters as 2-byte pairs
         // and decode as Shift_JIS afterwards
         byte[] buffer = new byte[2 * count];
         int offset = 0;
         while (count > 0)
         {
            // Each 13 bits encodes a 2-byte character
            int twoBytes = bits.readBits(13);
            int assembledTwoBytes = ((twoBytes / 0x0C0) << 8) | (twoBytes % 0x0C0);
            if (assembledTwoBytes < 0x01F00)
            {
               // In the 0x8140 to 0x9FFC range
               assembledTwoBytes += 0x08140;
            }
            else
            {
               // In the 0xE040 to 0xEBBF range
               assembledTwoBytes += 0x0C140;
            }
            buffer[offset] = (byte)(assembledTwoBytes >> 8);
            buffer[offset + 1] = (byte)assembledTwoBytes;
            offset += 2;
            count--;
         }
         // Shift_JIS may not be supported in some environments:
         try
         {
            result.Append(Encoding.GetEncoding(StringUtils.SHIFT_JIS).GetString(buffer, 0, buffer.Length));
         }
#if (WINDOWS_PHONE70 || WINDOWS_PHONE71 || SILVERLIGHT4 || SILVERLIGHT5 || NETFX_CORE || MONOANDROID || MONOTOUCH)
         catch (ArgumentException)
         {
            try
            {
               // Silverlight only supports a limited number of character sets, trying fallback to UTF-8
               result.Append(Encoding.GetEncoding("UTF-8").GetString(buffer, 0, buffer.Length));
            }
            catch (Exception)
            {
               return false;
            }
         }
#endif
         catch (Exception)
         {
            return false;
         }
         return true;
      }
      /// <summary>
      /// See specification GBT 18284-2000
      /// </summary>
      /// <param name="bits">The bits.</param>
      /// <param name="result">The result.</param>
      /// <param name="count">The count.</param>
      /// <returns></returns>
      private static bool decodeHanziSegment(BitSource bits,
                                             StringBuilder result,
                                             int count)
      {
         // Don't crash trying to read more bits than we have available.
         if (count * 13 > bits.available())
         {
            return false;
         }

         // Each character will require 2 bytes. Read the characters as 2-byte pairs
         // and decode as GB2312 afterwards
         byte[] buffer = new byte[2 * count];
         int offset = 0;
         while (count > 0)
         {
            // Each 13 bits encodes a 2-byte character
            int twoBytes = bits.readBits(13);
            int assembledTwoBytes = ((twoBytes / 0x060) << 8) | (twoBytes % 0x060);
            if (assembledTwoBytes < 0x003BF)
            {
               // In the 0xA1A1 to 0xAAFE range
               assembledTwoBytes += 0x0A1A1;
            }
            else
            {
               // In the 0xB0A1 to 0xFAFE range
               assembledTwoBytes += 0x0A6A1;
            }
            buffer[offset] = (byte)((assembledTwoBytes >> 8) & 0xFF);
            buffer[offset + 1] = (byte)(assembledTwoBytes & 0xFF);
            offset += 2;
            count--;
         }

         try
         {
            result.Append(Encoding.GetEncoding(StringUtils.GB2312).GetString(buffer, 0, buffer.Length));
         }
#if (WINDOWS_PHONE70 || WINDOWS_PHONE71 || SILVERLIGHT4 || SILVERLIGHT5 || NETFX_CORE || MONOANDROID || MONOTOUCH)
         catch (ArgumentException)
         {
            try
            {
               // Silverlight only supports a limited number of character sets, trying fallback to UTF-8
               result.Append(Encoding.GetEncoding("UTF-8").GetString(buffer, 0, buffer.Length));
            }
            catch (Exception)
            {
               return false;
            }
         }
#endif
         catch (Exception)
         {
            return false;
         }

         return true;
      }
		private static bool decodeByteSegment (BitSource bits,
		                                          StringBuilder result,
		                                          int count,
		                                          CharacterSetECI currentCharacterSetECI,
		                                          IList<byte[]> byteSegments,
		                                          IDictionary<DecodeHintType, object> hints)
		{
			// Don't crash trying to read more bits than we have available.
			if (count << 3 > bits.available ()) {
				return false;
			}

			byte[] readBytes = new byte[count];
			for (int i = 0; i < count; i++) {
				readBytes [i] = (byte)bits.readBits (8);
			}
			String encoding;
			if (currentCharacterSetECI == null) {
				// The spec isn't clear on this mode; see
				// section 6.4.5: t does not say which encoding to assuming
				// upon decoding. I have seen ISO-8859-1 used as well as
				// Shift_JIS -- without anything like an ECI designator to
				// give a hint.
				encoding = StringUtils.guessEncoding (readBytes, hints);
			} else {
				encoding = currentCharacterSetECI.EncodingName;
			}
			try {
				result.Append (Encoding.GetEncoding (encoding).GetString (readBytes, 0, readBytes.Length));
			}
#if (WINDOWS_PHONE70 || WINDOWS_PHONE71 || SILVERLIGHT4 || SILVERLIGHT5 || NETFX_CORE || MONOANDROID || MONOTOUCH)
         catch (ArgumentException)
         {
            try
            {
               // Silverlight only supports a limited number of character sets, trying fallback to UTF-8
               result.Append(Encoding.GetEncoding("UTF-8").GetString(readBytes, 0, readBytes.Length));
            }
            catch (Exception)
            {
               return false;
            }
         }
#endif
#if WindowsCE
         catch (PlatformNotSupportedException)
         {
            try
            {
               // WindowsCE doesn't support all encodings. But it is device depended.
               // So we try here the some different ones
               if (encoding == "ISO-8859-1")
               {
                  result.Append(Encoding.GetEncoding(1252).GetString(readBytes, 0, readBytes.Length));
               }
               else
               {
                  result.Append(Encoding.GetEncoding("UTF-8").GetString(readBytes, 0, readBytes.Length));
               }
            }
            catch (Exception)
            {
               return false;
            }
         }
#endif
         catch (Exception) {
				return false;
			}
			byteSegments.Add (readBytes);

			return true;
		}
      /// <summary>
      /// See ISO 16022:2006, 5.2.9 and Annex B, B.2
      /// </summary>
      private static bool decodeBase256Segment(BitSource bits,
                                               StringBuilder result,
                                               IList<byte[]> byteSegments)
      {
         // Figure out how long the Base 256 Segment is.
         int codewordPosition = 1 + bits.ByteOffset; // position is 1-indexed
         int d1 = unrandomize255State(bits.readBits(8), codewordPosition++);
         int count;
         if (d1 == 0)
         {  // Read the remainder of the symbol
            count = bits.available() / 8;
         }
         else if (d1 < 250)
         {
            count = d1;
         }
         else
         {
            count = 250 * (d1 - 249) + unrandomize255State(bits.readBits(8), codewordPosition++);
         }

         // We're seeing NegativeArraySizeException errors from users.
         if (count < 0)
         {
            return false;
         }

         byte[] bytes = new byte[count];
         for (int i = 0; i < count; i++)
         {
            // Have seen this particular error in the wild, such as at
            // http://www.bcgen.com/demo/IDAutomationStreamingDataMatrix.aspx?MODE=3&D=Fred&PFMT=3&PT=F&X=0.3&O=0&LM=0.2
            if (bits.available() < 8)
            {
               return false;
            }
            bytes[i] = (byte)unrandomize255State(bits.readBits(8), codewordPosition++);
         }
         byteSegments.Add(bytes);
         try
         {
#if (WINDOWS_PHONE70 || WINDOWS_PHONE71 || WINDOWS_PHONE80 || SILVERLIGHT4 || SILVERLIGHT5 || NETFX_CORE || WindowsCE || PORTABLE)
#if WindowsCE
            result.Append(Encoding.GetEncoding(1252).GetString(bytes, 0, bytes.Length));
#else
            result.Append(Encoding.GetEncoding("ISO-8859-1").GetString(bytes, 0, bytes.Length));
#endif
#else
            result.Append(Encoding.GetEncoding("ISO-8859-1").GetString(bytes));
#endif
         }
         catch (Exception uee)
         {
            throw new InvalidOperationException("Platform does not support required encoding: " + uee);
         }

         return true;
      }
      internal static DecoderResult decode(byte[] bytes,
                                           Version version,
                                           ErrorCorrectionLevel ecLevel,
                                           IDictionary<DecodeHintType, object> hints)
      {
         var bits = new BitSource(bytes);
         var result = new StringBuilder(50);
         var byteSegments = new List<byte[]>(1);
         var symbolSequence = -1;
         var parityData = -1;

         try
         {
            // CharacterSetECI currentCharacterSetECI = null;
            bool fc1InEffect = false;
            Mode mode;
            do
            {
               // While still another segment to read...
               if (bits.available() < 4)
               {
                  // OK, assume we're done. Really, a TERMINATOR mode should have been recorded here
                  mode = Mode.TERMINATOR;
               }
               else
               {
                  try
                  {
                     mode = Mode.forBits(bits.readBits(4)); // mode is encoded by 4 bits
                  }
                  catch (ArgumentException)
                  {
                     return null;
                  }
               }
               if (mode != Mode.TERMINATOR)
               {
                  if (mode == Mode.FNC1_FIRST_POSITION || mode == Mode.FNC1_SECOND_POSITION)
                  {
                     // We do little with FNC1 except alter the parsed result a bit according to the spec
                     fc1InEffect = true;
                  }
                  else if (mode == Mode.STRUCTURED_APPEND)
                  {
                     if (bits.available() < 16)
                     {
                        return null;
                     }
                     // not really supported; but sequence number and parity is added later to the result metadata
                     // Read next 8 bits (symbol sequence #) and 8 bits (parity data), then continue
                     symbolSequence = bits.readBits(8);
                     parityData = bits.readBits(8);
                  }
                  else if (mode == Mode.ECI)
                  {
                      /*
                     // Count doesn't apply to ECI
                     int value = parseECIValue(bits);
                     currentCharacterSetECI = CharacterSetECI.getCharacterSetECIByValue(value);
                     if (currentCharacterSetECI == null)
                     {
                        return null;
                     }
                       * */
                  }
                  else
                  {
                     // First handle Hanzi mode which does not start with character count
                     if (mode == Mode.HANZI)
                     {
                        //chinese mode contains a sub set indicator right after mode indicator
                        int subset = bits.readBits(4);
                        int countHanzi = bits.readBits(mode.getCharacterCountBits(version));
                        if (subset == GB2312_SUBSET)
                        {
                           if (!decodeHanziSegment(bits, result, countHanzi))
                              return null;
                        }
                     }
                     else
                     {
                        // "Normal" QR code modes:
                        // How many characters will follow, encoded in this mode?
                        int count = bits.readBits(mode.getCharacterCountBits(version));
                        if (mode == Mode.NUMERIC)
                        {
                           if (!decodeNumericSegment(bits, result, count))
                              return null;
                        }
                        else if (mode == Mode.ALPHANUMERIC)
                        {
                           if (!decodeAlphanumericSegment(bits, result, count, fc1InEffect))
                              return null;
                        }
                        else if (mode == Mode.BYTE)
                        {
                           if (!decodeByteSegment(bits, result, count, byteSegments, hints))
                              return null;
                        }
                        else if (mode == Mode.KANJI)
                        {
                           if (!decodeKanjiSegment(bits, result, count))
                              return null;
                        }
                        else
                        {
                           return null;
                        }
                     }
                  }
               }
            } while (mode != Mode.TERMINATOR);
         }
         catch (ArgumentException)
         {
            // from readBits() calls
            return null;
         }

#if WindowsCE
         var resultString = result.ToString().Replace("\n", "\r\n");
#else
         var resultString = result.ToString().Replace("\r\n", "\n").Replace("\n", Environment.NewLine);
#endif
         return new DecoderResult(bytes,
                                  resultString,
                                  byteSegments.Count == 0 ? null : byteSegments,
                                  ecLevel == null ? null : ecLevel.ToString(),
                                  symbolSequence, parityData);
      }
示例#17
0
      /// <summary>
      /// See specification GBT 18284-2000
      /// </summary>
      /// <param name="bits">The bits.</param>
      /// <param name="result">The result.</param>
      /// <param name="count">The count.</param>
      /// <returns></returns>
      private static bool decodeHanziSegment(BitSource bits,
                                             StringBuilder result,
                                             int count)
      {
         // Don't crash trying to read more bits than we have available.
         if (count * 13 > bits.available())
         {
            return false;
         }

         // Each character will require 2 bytes. Read the characters as 2-byte pairs
         // and decode as GB2312 afterwards
         byte[] buffer = new byte[2 * count];
         int offset = 0;
         while (count > 0)
         {
            // Each 13 bits encodes a 2-byte character
            int twoBytes = bits.readBits(13);
            int assembledTwoBytes = ((twoBytes / 0x060) << 8) | (twoBytes % 0x060);
            if (assembledTwoBytes < 0x003BF)
            {
               // In the 0xA1A1 to 0xAAFE range
               assembledTwoBytes += 0x0A1A1;
            }
            else
            {
               // In the 0xB0A1 to 0xFAFE range
               assembledTwoBytes += 0x0A6A1;
            }
            buffer[offset] = (byte)((assembledTwoBytes >> 8) & 0xFF);
            buffer[offset + 1] = (byte)(assembledTwoBytes & 0xFF);
            offset += 2;
            count--;
         }

         try
         {
            result.Append(Encoding.GetEncoding(StringUtils.GB2312).GetString(buffer, 0, buffer.Length));
         }
         catch (Exception)
         {
            return false;
         }

         return true;
      }