uniapp 微信小程序生成二维码

<view class="qr-box">
     <canvas canvas-id="qrcode" style="width: 340rpx;height: 340rpx;;margin: 0 auto;" />
</view>

<script>
    import uQRCode from '@/common/uqrcode.js' //引入uqrcode.js
    export default {
        data() {
            return {

            }
        },
        onl oad(options) {
            let url = 'customerId=1'
                        this.qrCode(url)
        }, 
        methods: {
          　　qrCode(url) {
                this.qrShow = true
                uQRCode.make({
                    canvasId: 'qrcode',
                    componentInstance: this,
                    text: url,
                    size: 170,
                    margin: 0,
                    backgroundColor: '#ffffff',
                    foregroundColor: '#000000',
                    fileType: 'jpg',
                    errorCorrectLevel: uQRCode.errorCorrectLevel.H,
                    success: res => {}
                })
            }
        }
    }
</script>

.qr-box {
        width: 400rpx;
        height: 460rpx;
        margin: 0 auto;
        margin-top: 150rpx;
    }

uqrcode.js

// uqrcode.js
//---------------------------------------------------------------------
// github https://github.com/Sansnn/uQRCode
//---------------------------------------------------------------------

let uQRCode = {};

(function() {
    //---------------------------------------------------------------------
    // QRCode for JavaScript
    //
    // Copyright (c) 2009 Kazuhiko Arase
    //
    // URL: http://www.d-project.com/
    //
    // Licensed under the MIT license:
    //   http://www.opensource.org/licenses/mit-license.php
    //
    // The word "QR Code" is registered trademark of 
    // DENSO WAVE INCORPORATED
    //   http://www.denso-wave.com/qrcode/faqpatent-e.html
    //
    //---------------------------------------------------------------------

    //---------------------------------------------------------------------
    // QR8bitByte
    //---------------------------------------------------------------------

    function QR8bitByte(data) {
        this.mode = QRMode.MODE_8BIT_BYTE;
        this.data = data;
    }

    QR8bitByte.prototype = {

        getLength: function(buffer) {
            return this.data.length;
        },

        write: function(buffer) {
            for (var i = 0; i < this.data.length; i++) {
                // not JIS ...
                buffer.put(this.data.charCodeAt(i), 8);
            }
        }
    };

    //---------------------------------------------------------------------
    // QRCode
    //---------------------------------------------------------------------

    function QRCode(typeNumber, errorCorrectLevel) {
        this.typeNumber = typeNumber;
        this.errorCorrectLevel = errorCorrectLevel;
        this.modules = null;
        this.moduleCount = 0;
        this.dataCache = null;
        this.dataList = new Array();
    }

    QRCode.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() {
            // Calculate automatically typeNumber if provided is < 1
            if (this.typeNumber < 1) {
                var typeNumber = 1;
                for (typeNumber = 1; typeNumber < 40; typeNumber++) {
                    var rsBlocks = QRRSBlock.getRSBlocks(typeNumber, this.errorCorrectLevel);

                    var buffer = new QRBitBuffer();
                    var totalDataCount = 0;
                    for (var i = 0; i < rsBlocks.length; i++) {
                        totalDataCount += rsBlocks[i].dataCount;
                    }

                    for (var i = 0; i < this.dataList.length; i++) {
                        var data = this.dataList[i];
                        buffer.put(data.mode, 4);
                        buffer.put(data.getLength(), QRUtil.getLengthInBits(data.mode, typeNumber));
                        data.write(buffer);
                    }
                    if (buffer.getLengthInBits() <= totalDataCount * 8)
                        break;
                }
                this.typeNumber = typeNumber;
            }
            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; //(col + row) % 3;
                }
            }

            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 = QRCode.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);

            // vertical        
            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;
                }
            }

            // horizontal
            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;
                }
            }

            // fixed module
            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;
                    }
                }
            }

        }

    };

    QRCode.PAD0 = 0xEC;
    QRCode.PAD1 = 0x11;

    QRCode.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);
        }

        // calc num max data.
        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 +
                ")");
        }

        // end code
        if (buffer.getLengthInBits() + 4 <= totalDataCount * 8) {
            buffer.put(0, 4);
        }

        // padding
        while (buffer.getLengthInBits() % 8 != 0) {
            buffer.putBit(false);
        }

        // padding
        while (true) {

            if (buffer.getLengthInBits() >= totalDataCount * 8) {
                break;
            }
            buffer.put(QRCode.PAD0, 8);

            if (buffer.getLengthInBits() >= totalDataCount * 8) {
                break;
            }
            buffer.put(QRCode.PAD1, 8);
        }

        return QRCode.createBytes(buffer, rsBlocks);
    }

    QRCode.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;

    }

    //---------------------------------------------------------------------
    // QRMode
    //---------------------------------------------------------------------

    var QRMode = {
        MODE_NUMBER: 1 << 0,
        MODE_ALPHA_NUM: 1 << 1,
        MODE_8BIT_BYTE: 1 << 2,
        MODE_KANJI: 1 << 3
    };

    //---------------------------------------------------------------------
    // QRErrorCorrectLevel
    //---------------------------------------------------------------------

    var QRErrorCorrectLevel = {
        L: 1,
        M: 0,
        Q: 3,
        H: 2
    };

    //---------------------------------------------------------------------
    // QRMaskPattern
    //---------------------------------------------------------------------

    var QRMaskPattern = {
        PATTERN000: 0,
        PATTERN001: 1,
        PATTERN010: 2,
        PATTERN011: 3,
        PATTERN100: 4,
        PATTERN101: 5,
        PATTERN110: 6,
        PATTERN111: 7
    };

    //---------------------------------------------------------------------
    // QRUtil
    //---------------------------------------------------------------------

    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) {

                // 1 - 9

                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) {

                // 10 - 26

                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) {

                // 27 - 40

                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;

            // LEVEL1

            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);
                    }
                }
            }

            // LEVEL2

            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;
                    }
                }
            }

            // LEVEL3

            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;
                    }
                }
            }

            // LEVEL4

            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;
        }

    };


    //---------------------------------------------------------------------
    // QRMath
    //---------------------------------------------------------------------

    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;
    }

    //---------------------------------------------------------------------
    // QRPolynomial
    //---------------------------------------------------------------------

    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);
            }

            // recursive call
            return new QRPolynomial(num, 0).mod(e);
        }
    };

    //---------------------------------------------------------------------
    // QRRSBlock
    //---------------------------------------------------------------------

    function QRRSBlock(totalCount, dataCount) {
        this.totalCount = totalCount;
        this.dataCount = dataCount;
    }

    QRRSBlock.RS_BLOCK_TABLE = [

        // L
        // M
        // Q
        // H

        // 1
        [1, 26, 19],
        [1, 26, 16],
        [1, 26, 13],
        [1, 26, 9],

        // 2
        [1, 44, 34],
        [1, 44, 28],
        [1, 44, 22],
        [1, 44, 16],

        // 3
        [1, 70, 55],
        [1, 70, 44],
        [2, 35, 17],
        [2, 35, 13],

        // 4        
        [1, 100, 80],
        [2, 50, 32],
        [2, 50, 24],
        [4, 25, 9],

        // 5
        [1, 134, 108],
        [2, 67, 43],
        [2, 33, 15, 2, 34, 16],
        [2, 33, 11, 2, 34, 12],

        // 6
        [2, 86, 68],
        [4, 43, 27],
        [4, 43, 19],
        [4, 43, 15],

        // 7        
        [2, 98, 78],
        [4, 49, 31],
        [2, 32, 14, 4, 33, 15],
        [4, 39, 13, 1, 40, 14],

        // 8
        [2, 121, 97],
        [2, 60, 38, 2, 61, 39],
        [4, 40, 18, 2, 41, 19],
        [4, 40, 14, 2, 41, 15],

        // 9
        [2, 146, 116],
        [3, 58, 36, 2, 59, 37],
        [4, 36, 16, 4, 37, 17],
        [4, 36, 12, 4, 37, 13],

        // 10        
        [2, 86, 68, 2, 87, 69],
        [4, 69, 43, 1, 70, 44],
        [6, 43, 19, 2, 44, 20],
        [6, 43, 15, 2, 44, 16],

        // 11
        [4, 101, 81],
        [1, 80, 50, 4, 81, 51],
        [4, 50, 22, 4, 51, 23],
        [3, 36, 12, 8, 37, 13],

        // 12
        [2, 116, 92, 2, 117, 93],
        [6, 58, 36, 2, 59, 37],
        [4, 46, 20, 6, 47, 21],
        [7, 42, 14, 4, 43, 15],

        // 13
        [4, 133, 107],
        [8, 59, 37, 1, 60, 38],
        [8, 44, 20, 4, 45, 21],
        [12, 33, 11, 4, 34, 12],

        // 14
        [3, 145, 115, 1, 146, 116],
        [4, 64, 40, 5, 65, 41],
        [11, 36, 16, 5, 37, 17],
        [11, 36, 12, 5, 37, 13],

        // 15
        [5, 109, 87, 1, 110, 88],
        [5, 65, 41, 5, 66, 42],
        [5, 54, 24, 7, 55, 25],
        [11, 36, 12],

        // 16
        [5, 122, 98, 1, 123, 99],
        [7, 73, 45, 3, 74, 46],
        [15, 43, 19, 2, 44, 20],
        [3, 45, 15, 13, 46, 16],

        // 17
        [1, 135, 107, 5, 136, 108],
        [10, 74, 46, 1, 75, 47],
        [1, 50, 22, 15, 51, 23],
        [2, 42, 14, 17, 43, 15],

        // 18
        [5, 150, 120, 1, 151, 121],
        [9, 69, 43, 4, 70, 44],
        [17, 50, 22, 1, 51, 23],
        [2, 42, 14, 19, 43, 15],

        // 19
        [3, 141, 113, 4, 142, 114],
        [3, 70, 44, 11, 71, 45],
        [17, 47, 21, 4, 48, 22],
        [9, 39, 13, 16, 40, 14],

        // 20
        [3, 135, 107, 5, 136, 108],
        [3, 67, 41, 13, 68, 42],
        [15, 54, 24, 5, 55, 25],
        [15, 43, 15, 10, 44, 16],

        // 21
        [4, 144, 116, 4, 145, 117],
        [17, 68, 42],
        [17, 50, 22, 6, 51, 23],
        [19, 46, 16, 6, 47, 17],

        // 22
        [2, 139, 111, 7, 140, 112],
        [17, 74, 46],
        [7, 54, 24, 16, 55, 25],
        [34, 37, 13],

        // 23
        [4, 151, 121, 5, 152, 122],
        [4, 75, 47, 14, 76, 48],
        [11, 54, 24, 14, 55, 25],
        [16, 45, 15, 14, 46, 16],

        // 24
        [6, 147, 117, 4, 148, 118],
        [6, 73, 45, 14, 74, 46],
        [11, 54, 24, 16, 55, 25],
        [30, 46, 16, 2, 47, 17],

        // 25
        [8, 132, 106, 4, 133, 107],
        [8, 75, 47, 13, 76, 48],
        [7, 54, 24, 22, 55, 25],
        [22, 45, 15, 13, 46, 16],

        // 26
        [10, 142, 114, 2, 143, 115],
        [19, 74, 46, 4, 75, 47],
        [28, 50, 22, 6, 51, 23],
        [33, 46, 16, 4, 47, 17],

        // 27
        [8, 152, 122, 4, 153, 123],
        [22, 73, 45, 3, 74, 46],
        [8, 53, 23, 26, 54, 24],
        [12, 45, 15, 28, 46, 16],

        // 28
        [3, 147, 117, 10, 148, 118],
        [3, 73, 45, 23, 74, 46],
        [4, 54, 24, 31, 55, 25],
        [11, 45, 15, 31, 46, 16],

        // 29
        [7, 146, 116, 7, 147, 117],
        [21, 73, 45, 7, 74, 46],
        [1, 53, 23, 37, 54, 24],
        [19, 45, 15, 26, 46, 16],

        // 30
        [5, 145, 115, 10, 146, 116],
        [19, 75, 47, 10, 76, 48],
        [15, 54, 24, 25, 55, 25],
        [23, 45, 15, 25, 46, 16],

        // 31
        [13, 145, 115, 3, 146, 116],
        [2, 74, 46, 29, 75, 47],
        [42, 54, 24, 1, 55, 25],
        [23, 45, 15, 28, 46, 16],

        // 32
        [17, 145, 115],
        [10, 74, 46, 23, 75, 47],
        [10, 54, 24, 35, 55, 25],
        [19, 45, 15, 35, 46, 16],

        // 33
        [17, 145, 115, 1, 146, 116],
        [14, 74, 46, 21, 75, 47],
        [29, 54, 24, 19, 55, 25],
        [11, 45, 15, 46, 46, 16],

        // 34
        [13, 145, 115, 6, 146, 116],
        [14, 74, 46, 23, 75, 47],
        [44, 54, 24, 7, 55, 25],
        [59, 46, 16, 1, 47, 17],

        // 35
        [12, 151, 121, 7, 152, 122],
        [12, 75, 47, 26, 76, 48],
        [39, 54, 24, 14, 55, 25],
        [22, 45, 15, 41, 46, 16],

        // 36
        [6, 151, 121, 14, 152, 122],
        [6, 75, 47, 34, 76, 48],
        [46, 54, 24, 10, 55, 25],
        [2, 45, 15, 64, 46, 16],

        // 37
        [17, 152, 122, 4, 153, 123],
        [29, 74, 46, 14, 75, 47],
        [49, 54, 24, 10, 55, 25],
        [24, 45, 15, 46, 46, 16],

        // 38
        [4, 152, 122, 18, 153, 123],
        [13, 74, 46, 32, 75, 47],
        [48, 54, 24, 14, 55, 25],
        [42, 45, 15, 32, 46, 16],

        // 39
        [20, 147, 117, 4, 148, 118],
        [40, 75, 47, 7, 76, 48],
        [43, 54, 24, 22, 55, 25],
        [10, 45, 15, 67, 46, 16],

        // 40
        [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 = new Array();

        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;
        }
    }

    //---------------------------------------------------------------------
    // QRBitBuffer
    //---------------------------------------------------------------------

    function QRBitBuffer() {
        this.buffer = new Array();
        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++;
        }
    };

    //---------------------------------------------------------------------
    // Support Chinese
    //---------------------------------------------------------------------
    function utf16To8(text) {
        var result = '';
        var c;
        for (var i = 0; i < text.length; i++) {
            c = text.charCodeAt(i);
            if (c >= 0x0001 && c <= 0x007F) {
                result += text.charAt(i);
            } else if (c > 0x07FF) {
                result += String.fromCharCode(0xE0 | c >> 12 & 0x0F);
                result += String.fromCharCode(0x80 | c >> 6 & 0x3F);
                result += String.fromCharCode(0x80 | c >> 0 & 0x3F);
            } else {
                result += String.fromCharCode(0xC0 | c >> 6 & 0x1F);
                result += String.fromCharCode(0x80 | c >> 0 & 0x3F);
            }
        }
        return result;
    }

    uQRCode = {

        errorCorrectLevel: QRErrorCorrectLevel,

        defaults: {
            size: 354,
            margin: 0,
            backgroundColor: '#ffffff',
            foregroundColor: '#000000',
            fileType: 'png', // 'jpg', 'png'
            errorCorrectLevel: QRErrorCorrectLevel.H,
            typeNumber: -1
        },

        make: function(options) {
            return new Promise((reslove, reject) => {
                var defaultOptions = {
                    canvasId: options.canvasId,
                    componentInstance: options.componentInstance,
                    text: options.text,
                    size: this.defaults.size,
                    margin: this.defaults.margin,
                    backgroundColor: this.defaults.backgroundColor,
                    foregroundColor: this.defaults.foregroundColor,
                    fileType: this.defaults.fileType,
                    errorCorrectLevel: this.defaults.errorCorrectLevel,
                    typeNumber: this.defaults.typeNumber
                };
                if (options) {
                    for (var i in options) {
                        defaultOptions[i] = options[i];
                    }
                }
                options = defaultOptions;
                if (!options.canvasId) {
                    console.error('uQRCode: Please set canvasId!');
                    return;
                }

                function createCanvas() {
                    var qrcode = new QRCode(options.typeNumber, options.errorCorrectLevel);
                    qrcode.addData(utf16To8(options.text));
                    qrcode.make();

                    var ctx = uni.createCanvasContext(options.canvasId, options.componentInstance);
                    ctx.setFillStyle(options.backgroundColor);
                    ctx.fillRect(0, 0, options.size, options.size);

                    var tileW = (options.size - options.margin * 2) / qrcode.getModuleCount();
                    var tileH = tileW;

                    for (var row = 0; row < qrcode.getModuleCount(); row++) {
                        for (var col = 0; col < qrcode.getModuleCount(); col++) {
                            var style = qrcode.isDark(row, col) ? options.foregroundColor : options.backgroundColor;
                            ctx.setFillStyle(style);
                            var x = Math.round(col * tileW) + options.margin;
                            var y = Math.round(row * tileH) + options.margin;
                            var w = Math.ceil((col + 1) * tileW) - Math.floor(col * tileW);
                            var h = Math.ceil((row + 1) * tileW) - Math.floor(row * tileW);
                            ctx.fillRect(x, y, w, h);
                        }
                    }

                    setTimeout(function() {
                        ctx.draw(false, (function() {
                            setTimeout(function() {
                                uni.canvasToTempFilePath({
                                    canvasId: options.canvasId,
                                    fileType: options.fileType,
                                    width: options.size,
                                    height: options.size,
                                    destWidth: options.size,
                                    destHeight: options.size,
                                    success: function(res) {
                                        let resData; // 将统一为base64格式
                                        let tempFilePath = res.tempFilePath; // H5为base64，其他为相对路径

                                        // #ifdef H5
                                        resData = tempFilePath;
                                        options.success && options.success(resData);
                                        reslove(resData);
                                        // #endif

                                        // #ifdef APP-PLUS
                                        const path = plus.io.convertLocalFileSystemURL(tempFilePath) // 绝对路径
                                        let fileReader = new plus.io.FileReader();
                                        fileReader.readAsDataURL(path);
                                        fileReader.onloadend = res => {
                                            resData = res.target.result;
                                            options.success && options.success(resData);
                                            reslove(resData);
                                        };
                                        // #endif

                                        // #ifdef MP-WEIXIN || MP-QQ || MP-TOUTIAO
                                        uni.getFileSystemManager().readFile({
                                            filePath: tempFilePath,
                                            encoding: 'base64',
                                            success: res => {
                                                resData = 'data:image/png;base64,' + res.data;
                                                options.success && options.success(resData);
                                                reslove(resData);
                                            }
                                        })
                                        // #endif

                                        // #ifndef H5 || APP-PLUS || MP-WEIXIN || MP-QQ || MP-TOUTIAO
                                        if (plus) {
                                            const path = plus.io.convertLocalFileSystemURL(tempFilePath) // 绝对路径
                                            let fileReader = new plus.io.FileReader();
                                            fileReader.readAsDataURL(path);
                                            fileReader.onloadend = res => {
                                                resData = res.target.result;
                                                options.success && options.success(resData);
                                                reslove(resData);
                                            };
                                        } else {
                                            uni.request({
                                                url: tempFilePath,
                                                method: 'GET',
                                                responseType: 'arraybuffer',
                                                success: res => {
                                                    resData = `data:image/png;base64,${uni.arrayBufferToBase64(res.data)}`; // 把arraybuffer转成base64
                                                    options.success && options.success(resData);
                                                    reslove(resData);
                                                }
                                            })
                                        }
                                        // #endif
                                    },
                                    fail: function(error) {
                                        options.fail && options.fail(error);
                                        reject(error);
                                    },
                                    complete: function(res) {
                                        options.complete && options.complete(res);
                                    }
                                }, options.componentInstance);
                            }, options.text.length + 100);
                        })());
                    }, 150);
                }

                createCanvas();
            });
        }
    }

})()

export default uQRCode

（支付宝小程序会有些些问题）

补充： base64格式要加上data:image/jpeg;base64,前缀

imgUrl = `data:image/jpeg;base64,${base64}`