最近遇到一个项目，api返回url地址，前端通过地址生成二维码。

话不多说直接上代码，亲测有效，希望能帮助大家，同时如果有更好的方法希望大家能够分享

1、第一步，在项目的utils文件夹下面创建一个weapp-qrcode.js文件（文件名随便，只展示我自己的）

2、将一下代码复制粘体到js文件中

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.parsedData = [];
		// Added to support UTF-8 Characters
		for (var i = 0, l = this.length; i < l; i++) {
			var byteArray = [];
			var code = this.charCodeAt(i);
			if (code > 65536) {
				byteArray[0] = 240 | ((code & 1835008) >>> 18);
				byteArray[1] = 128 | ((code & 258048) >>> 12);
				byteArray[2] = 128 | ((code & 4032) >>> 6);
				byteArray[3] = 128 | (code & 63);
			} else if (code > 2048) {
				byteArray[0] = 224 | ((code & 61440) >>> 12);
				byteArray[1] = 128 | ((code & 4032) >>> 6);
				byteArray[2] = 128 | (code & 63);
			} else if (code > 128) {
				byteArray[0] = 192 | ((code & 1984) >>> 6);
				byteArray[1] = 128 | (code & 63);
			} else {
				byteArray[0] = code;
			}
			this.parsedData.push(byteArray);
		}
		this.parsedData = Array.prototype.concat.apply([], this.parsedData);
		if (this.parsedData.length != this.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 = 236;
	QRCodeModel.PAD1 = 17;
	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] = 255 & 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,
		MODE_ALPHA_NUM: 2,
		MODE_8BIT_BYTE: 4,
		MODE_KANJI: 8
	};
	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: 1280 | 32 | 16 | 4 | 2 | 1,
		G18: 6144 | 1024 | 512 | 256 | 32 | 4 | 1,
		G15_MASK: 20480 | 1024 | 16 | 2,
		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] |= 128 >>> 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, callback) {
		this._oQRCode = new QRCodeModel(_getTypeNumber(sText, this._htOption.correctLevel), this._htOption
			.correctLevel);
		this._oQRCode.addData(sText);
		this._oQRCode.make();
		this.makeImage(callback);
	};
	QRCode.prototype.makeImage = function(callback) {
		var _oContext;
		if (this._htOption.usingIn) {
			_oContext = uni.createCanvasContext(this.canvasId, this._htOption.usingIn);
		} else {
			_oContext = uni.createCanvasContext(this.canvasId);
		}
		var _htOption = this._htOption;
		var oQRCode = this._oQRCode;
		var nCount = oQRCode.getModuleCount();
		var nWidth = _htOption.width / nCount;
		var nHeight = _htOption.height / nCount;
		var nRoundedWidth = Math.round(nWidth);
		var nRoundedHeight = Math.round(nHeight);
		if (_htOption.image && _htOption.image != '') {
			_oContext.drawImage(_htOption.image, 0, 0, _htOption.width, _htOption.height);
		}
		for (var row = 0; row < nCount; row++) {
			for (var col = 0; col < nCount; col++) {
				var bIsDark = oQRCode.isDark(row, col);
				var nLeft = col * nWidth + 5;
				var nTop = row * nHeight + 5;
				_oContext.setStrokeStyle(bIsDark ? _htOption.colorDark : _htOption.colorLight);
				// _oContext.setStrokeStyle('yellow')
				_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, nRoundedWidth,
					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, callback);
	};

	// 保存为图片，将临时路径传给回调
	QRCode.prototype.exportImage = function(callback) {
		if (!callback) {
			return;
		}
		uni.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: function(res) {
				callback(res.tempFilePath);
			},
			fail: (res) => {
				console.log(res);
			}
		});
	};
	QRCode.CorrectLevel = QRErrorCorrectLevel;
})();
// module.exports = QRCode;
export {
	QRCode
}

3、在你需要使用的.vue中创建canvas，如下

<template>
	<view>
		<canvas canvas-id="canvas" style="width: 110px; height: 125px"></canvas>
		<button @click="generateCode">生成二维码</button>
	</view>
</template>

<script>
	import {
		QRCode
	} from '对应文件的路径'
	export default {
		methods: {
			generateCode() {
				new QRCode('canvas', {
					text: 'https://www.baidi.com',
					width: 100,
					height: 100,
					colorDark: '#000000',
					colorLight: '#ffffff',
					correctLevel: QRCode.CorrectLevel.H
				})
			}
		}
	}
</script>