示例#1
0
 private static Version chooseVersion(int numInputBits, ErrorCorrectionLevel ecLevel)
 {
     // In the following comments, we use numbers of Version 7-H.
     for (int versionNum = 1; versionNum <= 40; versionNum++)
     {
         Version version = Version.getVersionForNumber(versionNum);
         // numBytes = 196
         int numBytes = version.TotalCodewords;
         // getNumECBytes = 130
         Version.ECBlocks ecBlocks = version.getECBlocksForLevel(ecLevel);
         int numEcBytes            = ecBlocks.TotalECCodewords;
         // getNumDataBytes = 196 - 130 = 66
         int numDataBytes    = numBytes - numEcBytes;
         int totalInputBytes = (numInputBits + 7) / 8;
         if (numDataBytes >= totalInputBytes)
         {
             return(version);
         }
     }
     throw new WriterException("Data too big");
 }
示例#2
0
        /// <summary>
        /// Encodes the specified content.
        /// </summary>
        /// <param name="content">The content.</param>
        /// <param name="ecLevel">The ec level.</param>
        /// <param name="hints">The hints.</param>
        /// <returns></returns>
        public static QRCode encode(String content,
                                    ErrorCorrectionLevel ecLevel,
                                    IDictionary <EncodeHintType, object> hints)
        {
            // Determine what character encoding has been specified by the caller, if any
#if !SILVERLIGHT || WINDOWS_PHONE
            String encoding = hints == null || !hints.ContainsKey(EncodeHintType.CHARACTER_SET) ? null : (String)hints[EncodeHintType.CHARACTER_SET];
            if (encoding == null)
            {
                encoding = DEFAULT_BYTE_MODE_ENCODING;
            }
            bool generateECI = !DEFAULT_BYTE_MODE_ENCODING.Equals(encoding);
#else
            // Silverlight supports only UTF-8 and UTF-16 out-of-the-box
            const string encoding = "UTF-8";
            // caller of the method can only control if the ECI segment should be written
            // character set is fixed to UTF-8; but some scanners doesn't like the ECI segment
            bool generateECI = (hints != null && hints.ContainsKey(EncodeHintType.CHARACTER_SET));
#endif

            // Pick an encoding mode appropriate for the content. Note that this will not attempt to use
            // multiple modes / segments even if that were more efficient. Twould be nice.
            Mode mode = chooseMode(content, encoding);

            // This will store the header information, like mode and
            // length, as well as "header" segments like an ECI segment.
            BitArray headerBits = new BitArray();

            // Append ECI segment if applicable
            if (mode == Mode.BYTE && generateECI)
            {
                CharacterSetECI eci = CharacterSetECI.getCharacterSetECIByName(encoding);
                if (eci != null)
                {
                    var eciIsExplicitDisabled = (hints != null && hints.ContainsKey(EncodeHintType.DISABLE_ECI) ? (bool)hints[EncodeHintType.DISABLE_ECI] : false);
                    if (!eciIsExplicitDisabled)
                    {
                        appendECI(eci, headerBits);
                    }
                }
            }

            // (With ECI in place,) Write the mode marker
            appendModeInfo(mode, headerBits);

            // Collect data within the main segment, separately, to count its size if needed. Don't add it to
            // main payload yet.
            BitArray dataBits = new BitArray();
            appendBytes(content, mode, dataBits, encoding);

            // Hard part: need to know version to know how many bits length takes. But need to know how many
            // bits it takes to know version. First we take a guess at version by assuming version will be
            // the minimum, 1:

            int provisionalBitsNeeded = headerBits.Size
                                        + mode.getCharacterCountBits(Version.getVersionForNumber(1))
                                        + dataBits.Size;
            Version provisionalVersion = chooseVersion(provisionalBitsNeeded, ecLevel);

            // Use that guess to calculate the right version. I am still not sure this works in 100% of cases.
            int bitsNeeded = headerBits.Size
                             + mode.getCharacterCountBits(provisionalVersion)
                             + dataBits.Size;
            Version version = chooseVersion(bitsNeeded, ecLevel);

            BitArray headerAndDataBits = new BitArray();
            headerAndDataBits.appendBitArray(headerBits);
            // Find "length" of main segment and write it
            int numLetters = mode == Mode.BYTE ? dataBits.SizeInBytes : content.Length;
            appendLengthInfo(numLetters, version, mode, headerAndDataBits);
            // Put data together into the overall payload
            headerAndDataBits.appendBitArray(dataBits);

            Version.ECBlocks ecBlocks = version.getECBlocksForLevel(ecLevel);
            int numDataBytes          = version.TotalCodewords - ecBlocks.TotalECCodewords;

            // Terminate the bits properly.
            terminateBits(numDataBytes, headerAndDataBits);

            // Interleave data bits with error correction code.
            BitArray finalBits = interleaveWithECBytes(headerAndDataBits,
                                                       version.TotalCodewords,
                                                       numDataBytes,
                                                       ecBlocks.NumBlocks);

            QRCode qrCode = new QRCode
            {
                ECLevel = ecLevel,
                Mode    = mode,
                Version = version
            };

            //  Choose the mask pattern and set to "qrCode".
            int        dimension   = version.DimensionForVersion;
            ByteMatrix matrix      = new ByteMatrix(dimension, dimension);
            int        maskPattern = chooseMaskPattern(finalBits, ecLevel, version, matrix);
            qrCode.MaskPattern = maskPattern;

            // Build the matrix and set it to "qrCode".
            MatrixUtil.buildMatrix(finalBits, ecLevel, version, maskPattern, matrix);
            qrCode.Matrix = matrix;

            return(qrCode);
        }