uniapp使用uQRCode绘制二维码，下载到本地，调起微信扫一扫二维码核销

1.效果
在这里插入图片描述
2.在utils文件夹下创建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 < 1if (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;}}// horizontalfor (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 modulethis.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 codeif (buffer.getLengthInBits() + 4 <= totalDataCount * 8) {buffer.put(0, 4);}// paddingwhile (buffer.getLengthInBits() % 8 != 0) {buffer.putBit(false);}// paddingwhile (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 - 9switch (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 - 26switch (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 - 40switch (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;// LEVEL1for (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);}}}// LEVEL2for (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;}}}// LEVEL3for (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;}}}// LEVEL4var 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 callreturn 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 H5resData = tempFilePath;options.success && options.success(resData);reslove(resData);// #endif// #ifdef APP-PLUSconst 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-TOUTIAOuni.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-TOUTIAOif (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base64options.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

3.在需要使用的页面引入js

<template>
<view>
<view class="codeBox" @click="save"><!-- 二维码 --><canvas id="qrcode" canvas-id="qrcode" style="width: 200px;height: 200px;"></canvas><view class="saveCode">保存二维码</view></view>
</view>
</template>
<script>import uqrCode from '@/utils/uqrcode.js'export default {data() {return {qrcode: false,imgCode: '', // 后续保存到手机相册所需要用到的字段}},onLoad(){this.generate('https://www.baidu.com?id=1')},methods:{//  生成二维码事件generate(e) {uqrCode.make({canvasId: 'qrcode',componentInstance: this,text: e, // 想生成二维码到内容size: 200,margin: 0,backgroundColor: '#ffffff',foregroundColor: '#000000',fileType: 'jpg',errorCorrectLevel: uqrCode.errorCorrectLevel.H,success: res => {this.imgCode = res // base64的图片格式}})},// 保存到手机save() {uni.getSetting({ //获取用户的当前设置success: (res) => {if (res.authSetting['scope.writePhotosAlbum']) { //验证用户是否授权可以访问相册this.aveImageToPhotosAlbum();} else {uni.authorize({ //如果没有授权，向用户发起请求scope: 'scope.writePhotosAlbum',success: () => {this.aveImageToPhotosAlbum();},fail: () => {// 提示uni.showToast({title: "请打开保存相册权限，再点击保存到手机",icon: "none",duration: 3000});setTimeout(() => {uni.openSetting({ //调起客户端小程序设置界面,让用户开启访问相册success: (res2) => {// console.log(res2.authSetting)}});}, 3000);}})}}})},aveImageToPhotosAlbum() {let base64 = this.imgCode.replace(/^data:image\/\w+;base64,/, ""); //去掉data:image/png;base64,let filePath = wx.env.USER_DATA_PATH + '/writeOff.png'; //   路径文件名uni.showLoading({title: '加载中',mask: true})uni.getFileSystemManager().writeFile({ // 获取全局唯一的文件管理器filePath: filePath, //创建一个临时文件名data: base64, //写入的文本或二进制数据encoding: 'base64', //写入当前文件的字符编码success: res => {uni.saveImageToPhotosAlbum({ // 保存图片到系统相册filePath: filePath,success: function(res2) {uni.hideLoading();uni.showToast({title: '保存成功',icon: "none",duration: 5000})},fail: function(err) {uni.hideLoading();// console.log(err.errMsg);}})},fail: err => {uni.hideLoading();//console.log(err)}})},}}

4.掉起微信扫一扫核销，将二维码扫出来的参数传个后端

<template><view><view  @click="scanCode">点击核销</view></view>
</template>
<script>export default {data() {return {}},onLoad() {},methods: {scanCode() {let that = this;uni.scanCode({onlyFromCamera: true, //只能通过相机扫码success: function(res) {console.log('扫码', res.result)let obj = {id:that.getQueryString(res.result,'id'),}uni.showLoading({mask: true,title: '核销中...'})setTimeout(res => {uni.hideLoading();}, 500)}});},// 解析链接中的参数getQueryString (url, name) {console.log("url = " + url)console.log("name = " + name)var reg = new RegExp('(^|&|/?)' + name + '=([^&|/?]*)(&|/?|$)', 'i')var r = url.substr(1).match(reg)if (r != null) {console.log("r = " + r)console.log("r[2] = " + r[2])return r[2]}return null;
}}}