微信小程序字符串展示为二维码

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微信小程序中要将一个字符串展示为二维码的形式,需要引入该js文件

// Core code comes from https://github.com/davidshimjs/qrcodejs
var QRCode;

(function () {
    /**
         * Get the type by string length
         * 
         * @private
         * @param {String} sText
         * @param {Number} nCorrectLevel
         * @return {Number} type
         */
    function _getTypeNumber(sText, nCorrectLevel) {
        var nType = 1;
        var length = _getUTF8Length(sText);

        for (var i = 0, len = QRCodeLimitLength.length; i <= len; i++) {
            var nLimit = 0;

            switch (nCorrectLevel) {
                case QRErrorCorrectLevel.L:
                    nLimit = QRCodeLimitLength[i][0];
                    break;
                case QRErrorCorrectLevel.M:
                    nLimit = QRCodeLimitLength[i][1];
                    break;
                case QRErrorCorrectLevel.Q:
                    nLimit = QRCodeLimitLength[i][2];
                    break;
                case QRErrorCorrectLevel.H:
                    nLimit = QRCodeLimitLength[i][3];
                    break;
            }

            if (length <= nLimit) {
                break;
            } else {
                nType++;
            }
        }

        if (nType > QRCodeLimitLength.length) {
            throw new Error("Too long data");
        }

        return nType;
    }

    function _getUTF8Length(sText) {
        var replacedText = encodeURI(sText).toString().replace(/\%[0-9a-fA-F]{2}/g, 'a');
        return replacedText.length + (replacedText.length != sText ? 3 : 0);
    }

    function QR8bitByte(data) {
        this.mode = QRMode.MODE_8BIT_BYTE;
        this.data = data;
        this.parsedData = [];

        // Added to support UTF-8 Characters
        for (var i = 0, l = this.data.length; i < l; i++) {
            var byteArray = [];
            var code = this.data.charCodeAt(i);

            if (code > 0x10000) {
                byteArray[0] = 0xF0 | ((code & 0x1C0000) >>> 18);
                byteArray[1] = 0x80 | ((code & 0x3F000) >>> 12);
                byteArray[2] = 0x80 | ((code & 0xFC0) >>> 6);
                byteArray[3] = 0x80 | (code & 0x3F);
            } else if (code > 0x800) {
                byteArray[0] = 0xE0 | ((code & 0xF000) >>> 12);
                byteArray[1] = 0x80 | ((code & 0xFC0) >>> 6);
                byteArray[2] = 0x80 | (code & 0x3F);
            } else if (code > 0x80) {
                byteArray[0] = 0xC0 | ((code & 0x7C0) >>> 6);
                byteArray[1] = 0x80 | (code & 0x3F);
            } else {
                byteArray[0] = code;
            }

            this.parsedData.push(byteArray);
        }

        this.parsedData = Array.prototype.concat.apply([], this.parsedData);

        if (this.parsedData.length != this.data.length) {
            this.parsedData.unshift(191);
            this.parsedData.unshift(187);
            this.parsedData.unshift(239);
        }
    }

    QR8bitByte.prototype = {
        getLength: function (buffer) {
            return this.parsedData.length;
        },
        write: function (buffer) {
            for (var i = 0, l = this.parsedData.length; i < l; i++) {
                buffer.put(this.parsedData[i], 8);
            }
        }
    };


    // QRCodeModel
    function QRCodeModel(typeNumber, errorCorrectLevel) {
        this.typeNumber = typeNumber;
        this.errorCorrectLevel = errorCorrectLevel;
        this.modules = null;
        this.moduleCount = 0;
        this.dataCache = null;
        this.dataList = [];
    }
    QRCodeModel.prototype = {
        addData: function (data) { var newData = new QR8bitByte(data); this.dataList.push(newData); this.dataCache = null; }, isDark: function (row, col) {
            if (row < 0 || this.moduleCount <= row || col < 0 || this.moduleCount <= col) { throw new Error(row + "," + col); }
            return this.modules[row][col];
        }, getModuleCount: function () { return this.moduleCount; }, make: function () { this.makeImpl(false, this.getBestMaskPattern()); }, makeImpl: function (test, maskPattern) {
            this.moduleCount = this.typeNumber * 4 + 17; this.modules = new Array(this.moduleCount); for (var row = 0; row < this.moduleCount; row++) { this.modules[row] = new Array(this.moduleCount); for (var col = 0; col < this.moduleCount; col++) { this.modules[row][col] = null; } }
            this.setupPositionProbePattern(0, 0); this.setupPositionProbePattern(this.moduleCount - 7, 0); this.setupPositionProbePattern(0, this.moduleCount - 7); this.setupPositionAdjustPattern(); this.setupTimingPattern(); this.setupTypeInfo(test, maskPattern); if (this.typeNumber >= 7) { this.setupTypeNumber(test); }
            if (this.dataCache == null) { this.dataCache = QRCodeModel.createData(this.typeNumber, this.errorCorrectLevel, this.dataList); }
            this.mapData(this.dataCache, maskPattern);
        }, setupPositionProbePattern: function (row, col) { for (var r = -1; r <= 7; r++) { if (row + r <= -1 || this.moduleCount <= row + r) continue; for (var c = -1; c <= 7; c++) { if (col + c <= -1 || this.moduleCount <= col + c) continue; if ((0 <= r && r <= 6 && (c == 0 || c == 6)) || (0 <= c && c <= 6 && (r == 0 || r == 6)) || (2 <= r && r <= 4 && 2 <= c && c <= 4)) { this.modules[row + r][col + c] = true; } else { this.modules[row + r][col + c] = false; } } } }, getBestMaskPattern: function () {
            var minLostPoint = 0; var pattern = 0; for (var i = 0; i < 8; i++) { this.makeImpl(true, i); var lostPoint = QRUtil.getLostPoint(this); if (i == 0 || minLostPoint > lostPoint) { minLostPoint = lostPoint; pattern = i; } }
            return pattern;
        }, createMovieClip: function (target_mc, instance_name, depth) {
            var qr_mc = target_mc.createEmptyMovieClip(instance_name, depth); var cs = 1; this.make(); for (var row = 0; row < this.modules.length; row++) { var y = row * cs; for (var col = 0; col < this.modules[row].length; col++) { var x = col * cs; var dark = this.modules[row][col]; if (dark) { qr_mc.beginFill(0, 100); qr_mc.moveTo(x, y); qr_mc.lineTo(x + cs, y); qr_mc.lineTo(x + cs, y + cs); qr_mc.lineTo(x, y + cs); qr_mc.endFill(); } } }
            return qr_mc;
        }, setupTimingPattern: function () {
            for (var r = 8; r < this.moduleCount - 8; r++) {
                if (this.modules[r][6] != null) { continue; }
                this.modules[r][6] = (r % 2 == 0);
            }
            for (var c = 8; c < this.moduleCount - 8; c++) {
                if (this.modules[6][c] != null) { continue; }
                this.modules[6][c] = (c % 2 == 0);
            }
        }, setupPositionAdjustPattern: function () {
            var pos = QRUtil.getPatternPosition(this.typeNumber); for (var i = 0; i < pos.length; i++) {
                for (var j = 0; j < pos.length; j++) {
                    var row = pos[i]; var col = pos[j]; if (this.modules[row][col] != null) { continue; }
                    for (var r = -2; r <= 2; r++) { for (var c = -2; c <= 2; c++) { if (r == -2 || r == 2 || c == -2 || c == 2 || (r == 0 && c == 0)) { this.modules[row + r][col + c] = true; } else { this.modules[row + r][col + c] = false; } } }
                }
            }
        }, setupTypeNumber: function (test) {
            var bits = QRUtil.getBCHTypeNumber(this.typeNumber); for (var i = 0; i < 18; i++) { var mod = (!test && ((bits >> i) & 1) == 1); this.modules[Math.floor(i / 3)][i % 3 + this.moduleCount - 8 - 3] = mod; }
            for (var i = 0; i < 18; i++) { var mod = (!test && ((bits >> i) & 1) == 1); this.modules[i % 3 + this.moduleCount - 8 - 3][Math.floor(i / 3)] = mod; }
        }, setupTypeInfo: function (test, maskPattern) {
            var data = (this.errorCorrectLevel << 3) | maskPattern; var bits = QRUtil.getBCHTypeInfo(data); for (var i = 0; i < 15; i++) { var mod = (!test && ((bits >> i) & 1) == 1); if (i < 6) { this.modules[i][8] = mod; } else if (i < 8) { this.modules[i + 1][8] = mod; } else { this.modules[this.moduleCount - 15 + i][8] = mod; } }
            for (var i = 0; i < 15; i++) { var mod = (!test && ((bits >> i) & 1) == 1); if (i < 8) { this.modules[8][this.moduleCount - i - 1] = mod; } else if (i < 9) { this.modules[8][15 - i - 1 + 1] = mod; } else { this.modules[8][15 - i - 1] = mod; } }
            this.modules[this.moduleCount - 8][8] = (!test);
        }, mapData: function (data, maskPattern) {
            var inc = -1; var row = this.moduleCount - 1; var bitIndex = 7; var byteIndex = 0; for (var col = this.moduleCount - 1; col > 0; col -= 2) {
                if (col == 6) col--; while (true) {
                    for (var c = 0; c < 2; c++) {
                        if (this.modules[row][col - c] == null) {
                            var dark = false; if (byteIndex < data.length) { dark = (((data[byteIndex] >>> bitIndex) & 1) == 1); }
                            var mask = QRUtil.getMask(maskPattern, row, col - c); if (mask) { dark = !dark; }
                            this.modules[row][col - c] = dark; bitIndex--; if (bitIndex == -1) { byteIndex++; bitIndex = 7; }
                        }
                    }
                    row += inc; if (row < 0 || this.moduleCount <= row) { row -= inc; inc = -inc; break; }
                }
            }
        }
    };
    QRCodeModel.PAD0 = 0xEC;
    QRCodeModel.PAD1 = 0x11;
    QRCodeModel.createData = function (typeNumber, errorCorrectLevel, dataList) {
        var rsBlocks = QRRSBlock.getRSBlocks(typeNumber, errorCorrectLevel); var buffer = new QRBitBuffer(); for (var i = 0; i < dataList.length; i++) { var data = dataList[i]; buffer.put(data.mode, 4); buffer.put(data.getLength(), QRUtil.getLengthInBits(data.mode, typeNumber)); data.write(buffer); }
        var totalDataCount = 0; for (var i = 0; i < rsBlocks.length; i++) { totalDataCount += rsBlocks[i].dataCount; }
        if (buffer.getLengthInBits() > totalDataCount * 8) {
            throw new Error("code length overflow. ("
                + buffer.getLengthInBits()
                + ">"
                + totalDataCount * 8
                + ")");
        }
        if (buffer.getLengthInBits() + 4 <= totalDataCount * 8) { buffer.put(0, 4); }
        while (buffer.getLengthInBits() % 8 != 0) { buffer.putBit(false); }
        while (true) {
            if (buffer.getLengthInBits() >= totalDataCount * 8) { break; }
            buffer.put(QRCodeModel.PAD0, 8); if (buffer.getLengthInBits() >= totalDataCount * 8) { break; }
            buffer.put(QRCodeModel.PAD1, 8);
        }
        return QRCodeModel.createBytes(buffer, rsBlocks);
    };
    QRCodeModel.createBytes = function (buffer, rsBlocks) {
        var offset = 0; var maxDcCount = 0; var maxEcCount = 0; var dcdata = new Array(rsBlocks.length); var ecdata = new Array(rsBlocks.length); for (var r = 0; r < rsBlocks.length; r++) {
            var dcCount = rsBlocks[r].dataCount; var ecCount = rsBlocks[r].totalCount - dcCount; maxDcCount = Math.max(maxDcCount, dcCount); maxEcCount = Math.max(maxEcCount, ecCount); dcdata[r] = new Array(dcCount); for (var i = 0; i < dcdata[r].length; i++) { dcdata[r][i] = 0xff & buffer.buffer[i + offset]; }
            offset += dcCount; var rsPoly = QRUtil.getErrorCorrectPolynomial(ecCount); var rawPoly = new QRPolynomial(dcdata[r], rsPoly.getLength() - 1); var modPoly = rawPoly.mod(rsPoly); ecdata[r] = new Array(rsPoly.getLength() - 1); for (var i = 0; i < ecdata[r].length; i++) { var modIndex = i + modPoly.getLength() - ecdata[r].length; ecdata[r][i] = (modIndex >= 0) ? modPoly.get(modIndex) : 0; }
        }
        var totalCodeCount = 0; for (var i = 0; i < rsBlocks.length; i++) { totalCodeCount += rsBlocks[i].totalCount; }
        var data = new Array(totalCodeCount); var index = 0; for (var i = 0; i < maxDcCount; i++) { for (var r = 0; r < rsBlocks.length; r++) { if (i < dcdata[r].length) { data[index++] = dcdata[r][i]; } } }
        for (var i = 0; i < maxEcCount; i++) { for (var r = 0; r < rsBlocks.length; r++) { if (i < ecdata[r].length) { data[index++] = ecdata[r][i]; } } }
        return data;
    };
    var QRMode = { MODE_NUMBER: 1 << 0, MODE_ALPHA_NUM: 1 << 1, MODE_8BIT_BYTE: 1 << 2, MODE_KANJI: 1 << 3 };
    var QRErrorCorrectLevel = { L: 1, M: 0, Q: 3, H: 2 };
    var QRMaskPattern = { PATTERN000: 0, PATTERN001: 1, PATTERN010: 2, PATTERN011: 3, PATTERN100: 4, PATTERN101: 5, PATTERN110: 6, PATTERN111: 7 };
    var QRUtil = {
        PATTERN_POSITION_TABLE: [[], [6, 18], [6, 22], [6, 26], [6, 30], [6, 34], [6, 22, 38], [6, 24, 42], [6, 26, 46], [6, 28, 50], [6, 30, 54], [6, 32, 58], [6, 34, 62], [6, 26, 46, 66], [6, 26, 48, 70], [6, 26, 50, 74], [6, 30, 54, 78], [6, 30, 56, 82], [6, 30, 58, 86], [6, 34, 62, 90], [6, 28, 50, 72, 94], [6, 26, 50, 74, 98], [6, 30, 54, 78, 102], [6, 28, 54, 80, 106], [6, 32, 58, 84, 110], [6, 30, 58, 86, 114], [6, 34, 62, 90, 118], [6, 26, 50, 74, 98, 122], [6, 30, 54, 78, 102, 126], [6, 26, 52, 78, 104, 130], [6, 30, 56, 82, 108, 134], [6, 34, 60, 86, 112, 138], [6, 30, 58, 86, 114, 142], [6, 34, 62, 90, 118, 146], [6, 30, 54, 78, 102, 126, 150], [6, 24, 50, 76, 102, 128, 154], [6, 28, 54, 80, 106, 132, 158], [6, 32, 58, 84, 110, 136, 162], [6, 26, 54, 82, 110, 138, 166], [6, 30, 58, 86, 114, 142, 170]], G15: (1 << 10) | (1 << 8) | (1 << 5) | (1 << 4) | (1 << 2) | (1 << 1) | (1 << 0), G18: (1 << 12) | (1 << 11) | (1 << 10) | (1 << 9) | (1 << 8) | (1 << 5) | (1 << 2) | (1 << 0), G15_MASK: (1 << 14) | (1 << 12) | (1 << 10) | (1 << 4) | (1 << 1), getBCHTypeInfo: function (data) {
            var d = data << 10; while (QRUtil.getBCHDigit(d) - QRUtil.getBCHDigit(QRUtil.G15) >= 0) { d ^= (QRUtil.G15 << (QRUtil.getBCHDigit(d) - QRUtil.getBCHDigit(QRUtil.G15))); }
            return ((data << 10) | d) ^ QRUtil.G15_MASK;
        }, getBCHTypeNumber: function (data) {
            var d = data << 12; while (QRUtil.getBCHDigit(d) - QRUtil.getBCHDigit(QRUtil.G18) >= 0) { d ^= (QRUtil.G18 << (QRUtil.getBCHDigit(d) - QRUtil.getBCHDigit(QRUtil.G18))); }
            return (data << 12) | d;
        }, getBCHDigit: function (data) {
            var digit = 0; while (data != 0) { digit++; data >>>= 1; }
            return digit;
        }, getPatternPosition: function (typeNumber) { return QRUtil.PATTERN_POSITION_TABLE[typeNumber - 1]; }, getMask: function (maskPattern, i, j) { switch (maskPattern) { case QRMaskPattern.PATTERN000: return (i + j) % 2 == 0; case QRMaskPattern.PATTERN001: return i % 2 == 0; case QRMaskPattern.PATTERN010: return j % 3 == 0; case QRMaskPattern.PATTERN011: return (i + j) % 3 == 0; case QRMaskPattern.PATTERN100: return (Math.floor(i / 2) + Math.floor(j / 3)) % 2 == 0; case QRMaskPattern.PATTERN101: return (i * j) % 2 + (i * j) % 3 == 0; case QRMaskPattern.PATTERN110: return ((i * j) % 2 + (i * j) % 3) % 2 == 0; case QRMaskPattern.PATTERN111: return ((i * j) % 3 + (i + j) % 2) % 2 == 0; default: throw new Error("bad maskPattern:" + maskPattern); } }, getErrorCorrectPolynomial: function (errorCorrectLength) {
            var a = new QRPolynomial([1], 0); for (var i = 0; i < errorCorrectLength; i++) { a = a.multiply(new QRPolynomial([1, QRMath.gexp(i)], 0)); }
            return a;
        }, getLengthInBits: function (mode, type) { if (1 <= type && type < 10) { switch (mode) { case QRMode.MODE_NUMBER: return 10; case QRMode.MODE_ALPHA_NUM: return 9; case QRMode.MODE_8BIT_BYTE: return 8; case QRMode.MODE_KANJI: return 8; default: throw new Error("mode:" + mode); } } else if (type < 27) { switch (mode) { case QRMode.MODE_NUMBER: return 12; case QRMode.MODE_ALPHA_NUM: return 11; case QRMode.MODE_8BIT_BYTE: return 16; case QRMode.MODE_KANJI: return 10; default: throw new Error("mode:" + mode); } } else if (type < 41) { switch (mode) { case QRMode.MODE_NUMBER: return 14; case QRMode.MODE_ALPHA_NUM: return 13; case QRMode.MODE_8BIT_BYTE: return 16; case QRMode.MODE_KANJI: return 12; default: throw new Error("mode:" + mode); } } else { throw new Error("type:" + type); } }, getLostPoint: function (qrCode) {
            var moduleCount = qrCode.getModuleCount(); var lostPoint = 0; for (var row = 0; row < moduleCount; row++) {
                for (var col = 0; col < moduleCount; col++) {
                    var sameCount = 0; var dark = qrCode.isDark(row, col); for (var r = -1; r <= 1; r++) {
                        if (row + r < 0 || moduleCount <= row + r) { continue; }
                        for (var c = -1; c <= 1; c++) {
                            if (col + c < 0 || moduleCount <= col + c) { continue; }
                            if (r == 0 && c == 0) { continue; }
                            if (dark == qrCode.isDark(row + r, col + c)) { sameCount++; }
                        }
                    }
                    if (sameCount > 5) { lostPoint += (3 + sameCount - 5); }
                }
            }
            for (var row = 0; row < moduleCount - 1; row++) { for (var col = 0; col < moduleCount - 1; col++) { var count = 0; if (qrCode.isDark(row, col)) count++; if (qrCode.isDark(row + 1, col)) count++; if (qrCode.isDark(row, col + 1)) count++; if (qrCode.isDark(row + 1, col + 1)) count++; if (count == 0 || count == 4) { lostPoint += 3; } } }
            for (var row = 0; row < moduleCount; row++) { for (var col = 0; col < moduleCount - 6; col++) { if (qrCode.isDark(row, col) && !qrCode.isDark(row, col + 1) && qrCode.isDark(row, col + 2) && qrCode.isDark(row, col + 3) && qrCode.isDark(row, col + 4) && !qrCode.isDark(row, col + 5) && qrCode.isDark(row, col + 6)) { lostPoint += 40; } } }
            for (var col = 0; col < moduleCount; col++) { for (var row = 0; row < moduleCount - 6; row++) { if (qrCode.isDark(row, col) && !qrCode.isDark(row + 1, col) && qrCode.isDark(row + 2, col) && qrCode.isDark(row + 3, col) && qrCode.isDark(row + 4, col) && !qrCode.isDark(row + 5, col) && qrCode.isDark(row + 6, col)) { lostPoint += 40; } } }
            var darkCount = 0; for (var col = 0; col < moduleCount; col++) { for (var row = 0; row < moduleCount; row++) { if (qrCode.isDark(row, col)) { darkCount++; } } }
            var ratio = Math.abs(100 * darkCount / moduleCount / moduleCount - 50) / 5; lostPoint += ratio * 10; return lostPoint;
        }
    };
    var QRMath = {
        glog: function (n) {
            if (n < 1) { throw new Error("glog(" + n + ")"); }
            return QRMath.LOG_TABLE[n];
        }, gexp: function (n) {
            while (n < 0) { n += 255; }
            while (n >= 256) { n -= 255; }
            return QRMath.EXP_TABLE[n];
        }, EXP_TABLE: new Array(256), LOG_TABLE: new Array(256)
    }; for (var i = 0; i < 8; i++) { QRMath.EXP_TABLE[i] = 1 << i; }
    for (var i = 8; i < 256; i++) { QRMath.EXP_TABLE[i] = QRMath.EXP_TABLE[i - 4] ^ QRMath.EXP_TABLE[i - 5] ^ QRMath.EXP_TABLE[i - 6] ^ QRMath.EXP_TABLE[i - 8]; }
    for (var i = 0; i < 255; i++) { QRMath.LOG_TABLE[QRMath.EXP_TABLE[i]] = i; }
    function QRPolynomial(num, shift) {
        if (num.length == undefined) { throw new Error(num.length + "/" + shift); }
        var offset = 0; while (offset < num.length && num[offset] == 0) { offset++; }
        this.num = new Array(num.length - offset + shift); for (var i = 0; i < num.length - offset; i++) { this.num[i] = num[i + offset]; }
    }
    QRPolynomial.prototype = {
        get: function (index) { return this.num[index]; }, getLength: function () { return this.num.length; }, multiply: function (e) {
            var num = new Array(this.getLength() + e.getLength() - 1); for (var i = 0; i < this.getLength(); i++) { for (var j = 0; j < e.getLength(); j++) { num[i + j] ^= QRMath.gexp(QRMath.glog(this.get(i)) + QRMath.glog(e.get(j))); } }
            return new QRPolynomial(num, 0);
        }, mod: function (e) {
            if (this.getLength() - e.getLength() < 0) { return this; }
            var ratio = QRMath.glog(this.get(0)) - QRMath.glog(e.get(0)); var num = new Array(this.getLength()); for (var i = 0; i < this.getLength(); i++) { num[i] = this.get(i); }
            for (var i = 0; i < e.getLength(); i++) { num[i] ^= QRMath.gexp(QRMath.glog(e.get(i)) + ratio); }
            return new QRPolynomial(num, 0).mod(e);
        }
    };
    function QRRSBlock(totalCount, dataCount) { this.totalCount = totalCount; this.dataCount = dataCount; }
    QRRSBlock.RS_BLOCK_TABLE = [[1, 26, 19], [1, 26, 16], [1, 26, 13], [1, 26, 9], [1, 44, 34], [1, 44, 28], [1, 44, 22], [1, 44, 16], [1, 70, 55], [1, 70, 44], [2, 35, 17], [2, 35, 13], [1, 100, 80], [2, 50, 32], [2, 50, 24], [4, 25, 9], [1, 134, 108], [2, 67, 43], [2, 33, 15, 2, 34, 16], [2, 33, 11, 2, 34, 12], [2, 86, 68], [4, 43, 27], [4, 43, 19], [4, 43, 15], [2, 98, 78], [4, 49, 31], [2, 32, 14, 4, 33, 15], [4, 39, 13, 1, 40, 14], [2, 121, 97], [2, 60, 38, 2, 61, 39], [4, 40, 18, 2, 41, 19], [4, 40, 14, 2, 41, 15], [2, 146, 116], [3, 58, 36, 2, 59, 37], [4, 36, 16, 4, 37, 17], [4, 36, 12, 4, 37, 13], [2, 86, 68, 2, 87, 69], [4, 69, 43, 1, 70, 44], [6, 43, 19, 2, 44, 20], [6, 43, 15, 2, 44, 16], [4, 101, 81], [1, 80, 50, 4, 81, 51], [4, 50, 22, 4, 51, 23], [3, 36, 12, 8, 37, 13], [2, 116, 92, 2, 117, 93], [6, 58, 36, 2, 59, 37], [4, 46, 20, 6, 47, 21], [7, 42, 14, 4, 43, 15], [4, 133, 107], [8, 59, 37, 1, 60, 38], [8, 44, 20, 4, 45, 21], [12, 33, 11, 4, 34, 12], [3, 145, 115, 1, 146, 116], [4, 64, 40, 5, 65, 41], [11, 36, 16, 5, 37, 17], [11, 36, 12, 5, 37, 13], [5, 109, 87, 1, 110, 88], [5, 65, 41, 5, 66, 42], [5, 54, 24, 7, 55, 25], [11, 36, 12], [5, 122, 98, 1, 123, 99], [7, 73, 45, 3, 74, 46], [15, 43, 19, 2, 44, 20], [3, 45, 15, 13, 46, 16], [1, 135, 107, 5, 136, 108], [10, 74, 46, 1, 75, 47], [1, 50, 22, 15, 51, 23], [2, 42, 14, 17, 43, 15], [5, 150, 120, 1, 151, 121], [9, 69, 43, 4, 70, 44], [17, 50, 22, 1, 51, 23], [2, 42, 14, 19, 43, 15], [3, 141, 113, 4, 142, 114], [3, 70, 44, 11, 71, 45], [17, 47, 21, 4, 48, 22], [9, 39, 13, 16, 40, 14], [3, 135, 107, 5, 136, 108], [3, 67, 41, 13, 68, 42], [15, 54, 24, 5, 55, 25], [15, 43, 15, 10, 44, 16], [4, 144, 116, 4, 145, 117], [17, 68, 42], [17, 50, 22, 6, 51, 23], [19, 46, 16, 6, 47, 17], [2, 139, 111, 7, 140, 112], [17, 74, 46], [7, 54, 24, 16, 55, 25], [34, 37, 13], [4, 151, 121, 5, 152, 122], [4, 75, 47, 14, 76, 48], [11, 54, 24, 14, 55, 25], [16, 45, 15, 14, 46, 16], [6, 147, 117, 4, 148, 118], [6, 73, 45, 14, 74, 46], [11, 54, 24, 16, 55, 25], [30, 46, 16, 2, 47, 17], [8, 132, 106, 4, 133, 107], [8, 75, 47, 13, 76, 48], [7, 54, 24, 22, 55, 25], [22, 45, 15, 13, 46, 16], [10, 142, 114, 2, 143, 115], [19, 74, 46, 4, 75, 47], [28, 50, 22, 6, 51, 23], [33, 46, 16, 4, 47, 17], [8, 152, 122, 4, 153, 123], [22, 73, 45, 3, 74, 46], [8, 53, 23, 26, 54, 24], [12, 45, 15, 28, 46, 16], [3, 147, 117, 10, 148, 118], [3, 73, 45, 23, 74, 46], [4, 54, 24, 31, 55, 25], [11, 45, 15, 31, 46, 16], [7, 146, 116, 7, 147, 117], [21, 73, 45, 7, 74, 46], [1, 53, 23, 37, 54, 24], [19, 45, 15, 26, 46, 16], [5, 145, 115, 10, 146, 116], [19, 75, 47, 10, 76, 48], [15, 54, 24, 25, 55, 25], [23, 45, 15, 25, 46, 16], [13, 145, 115, 3, 146, 116], [2, 74, 46, 29, 75, 47], [42, 54, 24, 1, 55, 25], [23, 45, 15, 28, 46, 16], [17, 145, 115], [10, 74, 46, 23, 75, 47], [10, 54, 24, 35, 55, 25], [19, 45, 15, 35, 46, 16], [17, 145, 115, 1, 146, 116], [14, 74, 46, 21, 75, 47], [29, 54, 24, 19, 55, 25], [11, 45, 15, 46, 46, 16], [13, 145, 115, 6, 146, 116], [14, 74, 46, 23, 75, 47], [44, 54, 24, 7, 55, 25], [59, 46, 16, 1, 47, 17], [12, 151, 121, 7, 152, 122], [12, 75, 47, 26, 76, 48], [39, 54, 24, 14, 55, 25], [22, 45, 15, 41, 46, 16], [6, 151, 121, 14, 152, 122], [6, 75, 47, 34, 76, 48], [46, 54, 24, 10, 55, 25], [2, 45, 15, 64, 46, 16], [17, 152, 122, 4, 153, 123], [29, 74, 46, 14, 75, 47], [49, 54, 24, 10, 55, 25], [24, 45, 15, 46, 46, 16], [4, 152, 122, 18, 153, 123], [13, 74, 46, 32, 75, 47], [48, 54, 24, 14, 55, 25], [42, 45, 15, 32, 46, 16], [20, 147, 117, 4, 148, 118], [40, 75, 47, 7, 76, 48], [43, 54, 24, 22, 55, 25], [10, 45, 15, 67, 46, 16], [19, 148, 118, 6, 149, 119], [18, 75, 47, 31, 76, 48], [34, 54, 24, 34, 55, 25], [20, 45, 15, 61, 46, 16]];
    QRRSBlock.getRSBlocks = function (typeNumber, errorCorrectLevel) {
        var rsBlock = QRRSBlock.getRsBlockTable(typeNumber, errorCorrectLevel); if (rsBlock == undefined) { throw new Error("bad rs block @ typeNumber:" + typeNumber + "/errorCorrectLevel:" + errorCorrectLevel); }
        var length = rsBlock.length / 3; var list = []; for (var i = 0; i < length; i++) { var count = rsBlock[i * 3 + 0]; var totalCount = rsBlock[i * 3 + 1]; var dataCount = rsBlock[i * 3 + 2]; for (var j = 0; j < count; j++) { list.push(new QRRSBlock(totalCount, dataCount)); } }
        return list;
    };
    QRRSBlock.getRsBlockTable = function (typeNumber, errorCorrectLevel) { switch (errorCorrectLevel) { case QRErrorCorrectLevel.L: return QRRSBlock.RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 0]; case QRErrorCorrectLevel.M: return QRRSBlock.RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 1]; case QRErrorCorrectLevel.Q: return QRRSBlock.RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 2]; case QRErrorCorrectLevel.H: return QRRSBlock.RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 3]; default: return undefined; } };
    function QRBitBuffer() { this.buffer = []; this.length = 0; }
    QRBitBuffer.prototype = {
        get: function (index) { var bufIndex = Math.floor(index / 8); return ((this.buffer[bufIndex] >>> (7 - index % 8)) & 1) == 1; }, put: function (num, length) { for (var i = 0; i < length; i++) { this.putBit(((num >>> (length - i - 1)) & 1) == 1); } }, getLengthInBits: function () { return this.length; }, putBit: function (bit) {
            var bufIndex = Math.floor(this.length / 8); if (this.buffer.length <= bufIndex) { this.buffer.push(0); }
            if (bit) { this.buffer[bufIndex] |= (0x80 >>> (this.length % 8)); }
            this.length++;
        }
    };
    var QRCodeLimitLength = [[17, 14, 11, 7], [32, 26, 20, 14], [53, 42, 32, 24], [78, 62, 46, 34], [106, 84, 60, 44], [134, 106, 74, 58], [154, 122, 86, 64], [192, 152, 108, 84], [230, 180, 130, 98], [271, 213, 151, 119], [321, 251, 177, 137], [367, 287, 203, 155], [425, 331, 241, 177], [458, 362, 258, 194], [520, 412, 292, 220], [586, 450, 322, 250], [644, 504, 364, 280], [718, 560, 394, 310], [792, 624, 442, 338], [858, 666, 482, 382], [929, 711, 509, 403], [1003, 779, 565, 439], [1091, 857, 611, 461], [1171, 911, 661, 511], [1273, 997, 715, 535], [1367, 1059, 751, 593], [1465, 1125, 805, 625], [1528, 1190, 868, 658], [1628, 1264, 908, 698], [1732, 1370, 982, 742], [1840, 1452, 1030, 790], [1952, 1538, 1112, 842], [2068, 1628, 1168, 898], [2188, 1722, 1228, 958], [2303, 1809, 1283, 983], [2431, 1911, 1351, 1051], [2563, 1989, 1423, 1093], [2699, 2099, 1499, 1139], [2809, 2213, 1579, 1219], [2953, 2331, 1663, 1273]];

    // QRCode object
    QRCode = function (canvasId, vOption) {
        this._htOption = {
            width: 256,
            height: 256,
            typeNumber: 4,
            colorDark: "#000000",
            colorLight: "#ffffff",
            correctLevel: QRErrorCorrectLevel.H
        };

        if (typeof vOption === 'string') {
            vOption = {
                text: vOption
            };
        }

        // Overwrites options
        if (vOption) {
            for (var i in vOption) {
                this._htOption[i] = vOption[i];
            }
        }

        this._oQRCode = null;
        this.canvasId = canvasId

        if (this._htOption.text && this.canvasId) {
            this.makeCode(this._htOption.text);
        }
    };

    QRCode.prototype.makeCode = function (sText) {
        this._oQRCode = new QRCodeModel(_getTypeNumber(sText, this._htOption.correctLevel), this._htOption.correctLevel);
        this._oQRCode.addData(sText);
        this._oQRCode.make();
        this.makeImage();
    };

    QRCode.prototype.makeImage = function () {
        var _oContext
        if (this._htOption.usingIn) {
            _oContext = wx.createCanvasContext(this.canvasId, this._htOption.usingIn)
        }
        else {
            _oContext = wx.createCanvasContext(this.canvasId)
        }
        var _htOption = this._htOption;
        var oQRCode = this._oQRCode

        var nCount = oQRCode.getModuleCount();
        var nWidth = _htOption.padding ? (_htOption.width - 2 * _htOption.padding) / nCount : _htOption.width / nCount;
        var nHeight = _htOption.padding ? (_htOption.height - 2 * _htOption.padding) / nCount : _htOption.height / nCount;
        var nRoundedHeight = Math.round(nHeight);
        var nRoundedWidth = Math.round(nWidth);

        if (_htOption.image && _htOption.image != '') {
            _oContext.drawImage(_htOption.image, 0, 0, _htOption.width, _htOption.height)
        }
        _oContext.setFillStyle('#fff')
        _oContext.fillRect(0, 0, _htOption.width, _htOption.height)
        _oContext.save()
        for (var row = 0; row < nCount; row++) {
            for (var col = 0; col < nCount; col++) {
                var bIsDark = oQRCode.isDark(row, col);
                var nLeft = _htOption.padding ? col * nWidth + _htOption.padding : col * nWidth;
                var nTop = _htOption.padding ? row * nHeight + _htOption.padding : row * nHeight;
                _oContext.setStrokeStyle(bIsDark ? _htOption.colorDark : _htOption.colorLight)
                // _oContext.setStrokeStyle('red')
                _oContext.setLineWidth(1)
                _oContext.setFillStyle(bIsDark ? _htOption.colorDark : _htOption.colorLight)
                // _oContext.setFillStyle('red')
                // if (bIsDark) {
                _oContext.fillRect(nLeft, nTop, nWidth, nHeight);
                // }

                // 안티 앨리어싱 방지 처리
                // if (bIsDark) {
                _oContext.strokeRect(
                    Math.floor(nLeft) + 0.5,
                    Math.floor(nTop) + 0.5,
                    nRoundedHeight
                );

                _oContext.strokeRect(
                    Math.ceil(nLeft) - 0.5,
                    Math.ceil(nTop) - 0.5,
                    nRoundedWidth,
                    nRoundedHeight
                );
                // }
                // _oContext.fillRect(
                //     Math.floor(nLeft) + 0.5,
                //     Math.floor(nTop) + 0.5,
                //     nRoundedWidth,
                //     nRoundedHeight
                // );
                // _oContext.fillRect(
                //     Math.ceil(nLeft) - 0.5,
                //     Math.ceil(nTop) - 0.5,
                //     nRoundedWidth,
                //     nRoundedHeight
                // );
                // _oContext.clearRect(
                //     Math.floor(nLeft) + 0.5,
                //     Math.floor(nTop) + 0.5,
                //     nRoundedWidth,
                //     nRoundedHeight
                // );
                // _oContext.clearRect(
                //     Math.ceil(nLeft) - 0.5,
                //     Math.ceil(nTop) - 0.5,
                //     nRoundedWidth,
                //     nRoundedHeight
                // );
            }
        }

        _oContext.draw(false, () => {
          setTimeout(() => {
            this.exportImage()
          }, 800)
        })
    };

    // 保存为图片,将临时路径传给回调
    QRCode.prototype.exportImage = function (callback) {
      if (this._htOption.callback && typeof this._htOption.callback === 'function') {
        wx.canvasToTempFilePath({
            x: 0,
            y: 0,
            width: this._htOption.width,
            height: this._htOption.height,
            destWidth: this._htOption.width,
            destHeight: this._htOption.height,
            canvasId: this.canvasId,
            success: (res) => {
              this._htOption.callback({path: res.tempFilePath})
            }
        })
      } 
    }

    QRCode.CorrectLevel = QRErrorCorrectLevel;
})();

module.exports = QRCode

在js文件中引入

var QRCode = require('../../utils/weapp-qrcode.js')

//生成二维码
  generateCode(text){
    var code = new QRCode('myQrcode',{
      text: text,
      width: 250,
      height: 250,
      padding: 12, // 生成二维码四周自动留边宽度,不传入默认为0
      correctLevel: QRCode.CorrectLevel.H, // 二维码可辨识度
      callback: (res) => {
        console.log(res)
        wx.hideLoading()
       // 接下来就可以直接调用微信小程序的api保存到本地或者将这张二维码直接画在海报上面去,看各自需求
      }
     })

wxml页面上显示

<canvas class="canvas-code" canvas-id="myQrcode" class="img3"/>
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