/// <summary> Encode "bytes" with the error correction level "ecLevel". The encoding mode will be chosen /// internally by chooseMode(). On success, store the result in "qrCode". /// /// We recommend you to use QRCode.EC_LEVEL_L (the lowest level) for /// "getECLevel" since our primary use is to show QR code on desktop screens. We don't need very /// strong error correction for this purpose. /// /// Note that there is no way to encode bytes in MODE_KANJI. We might want to add EncodeWithMode() /// with which clients can specify the encoding mode. For now, we don't need the functionality. /// </summary> public static void Encode(System.String content, ErrorCorrectionLevel ecLevel, QRCode qrCode) { Encode(content, ecLevel, null, qrCode); }
public static void Encode(System.String content, ErrorCorrectionLevel ecLevel, System.Collections.Hashtable hints, QRCode qrCode) { System.String encoding = hints == null?null:(System.String)hints[EncodeHintType.CHARACTER_SET]; if (encoding == null) { encoding = DEFAULT_BYTE_MODE_ENCODING; } // Step 1: Choose the mode (encoding). Mode mode = ChooseMode(content, encoding); // Step 2: Append "bytes" into "dataBits" in appropriate encoding. BitVector dataBits = new BitVector(); appendBytes(content, mode, dataBits, encoding); // Step 3: Initialize QR code that can contain "dataBits". int numInputBytes = dataBits.sizeInBytes(); InitQrCode(numInputBytes, ecLevel, mode, qrCode); // Step 4: Build another bit vector that contains header and data. BitVector headerAndDataBits = new BitVector(); // Step 4.5: Append ECI message if applicable if (mode == Mode.BYTE && !DEFAULT_BYTE_MODE_ENCODING.Equals(encoding)) { CharacterSetECI eci = CharacterSetECI.getCharacterSetECIByName(encoding); if (eci != null) { AppendECI(eci, headerAndDataBits); } } appendModeInfo(mode, headerAndDataBits); int numLetters = mode.Equals(Mode.BYTE)?dataBits.sizeInBytes():content.Length; appendLengthInfo(numLetters, qrCode.Version, mode, headerAndDataBits); headerAndDataBits.appendBitVector(dataBits); // Step 5: Terminate the bits properly. TerminateBits(qrCode.NumDataBytes, headerAndDataBits); // Step 6: Interleave data bits with error correction code. BitVector finalBits = new BitVector(); InterleaveWithEcBytes(headerAndDataBits, qrCode.NumTotalBytes, qrCode.NumDataBytes, qrCode.NumRSBlocks, finalBits); // Step 7: Choose the mask pattern and set to "qrCode". ByteMatrix matrix = new ByteMatrix(qrCode.MatrixWidth, qrCode.MatrixWidth); qrCode.MaskPattern = ChooseMaskPattern(finalBits, qrCode.ECLevel, qrCode.Version, matrix); // Step 8. Build the matrix and set it to "qrCode". MatrixUtil.buildMatrix(finalBits, qrCode.ECLevel, qrCode.Version, qrCode.MaskPattern, matrix); qrCode.Matrix = matrix; // Step 9. Make sure we have a valid QR Code. if (!qrCode.Valid) { throw new WriterException(string.Format("Invalid QR code: {0}", qrCode)); } }
/// <summary> Initialize "qrCode" according to "numInputBytes", "ecLevel", and "mode". On success, /// modify "qrCode". /// </summary> private static void InitQrCode(int numInputBytes, ErrorCorrectionLevel ecLevel, Mode mode, QRCode qrCode) { qrCode.ECLevel = ecLevel; qrCode.Mode = mode; // 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; // getNumRSBlocks = 5 int numRSBlocks = ecBlocks.NumBlocks; // getNumDataBytes = 196 - 130 = 66 int numDataBytes = numBytes - numEcBytes; // We want to choose the smallest version which can contain data of "numInputBytes" + some // extra bits for the header (mode info and length info). The header can be three bytes // (precisely 4 + 16 bits) at most. Hence we do +3 here. if (numDataBytes >= numInputBytes + 3) { // Yay, we found the proper rs block info! qrCode.Version = versionNum; qrCode.NumTotalBytes = numBytes; qrCode.NumDataBytes = numDataBytes; qrCode.NumRSBlocks = numRSBlocks; // getNumECBytes = 196 - 66 = 130 qrCode.NumECBytes = numEcBytes; // matrix width = 21 + 6 * 4 = 45 qrCode.MatrixWidth = version.DimensionForVersion; return; } } throw new WriterException("Cannot find proper rs block info (input data too big?)"); }