微信小程序如何通过js生成二维码？
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在小程序目录utils新建qrcode.js
// Core code comes from https://github.com/davidshimjs/qrcodejs
var QRCode;
(function () {
/**
* Get the type by string length
*
* @private
* @param {String} sText
* @param {Number} nCorrectLevel
* @return {Number} type
*/
function _getTypeNumber(sText, nCorrectLevel) {
var nType = 1;
var length = _getUTF8Length(sText);
for (var i = 0, len = QRCodeLimitLength.length; i <= len; i++) {
var nLimit = 0;
switch (nCorrectLevel) {
case QRErrorCorrectLevel.L:
nLimit = QRCodeLimitLength[i][0];
break;
case QRErrorCorrectLevel.M:
nLimit = QRCodeLimitLength[i][1];
break;
case QRErrorCorrectLevel.Q:
nLimit = QRCodeLimitLength[i][2];
break;
case QRErrorCorrectLevel.H:
nLimit = QRCodeLimitLength[i][3];
break;
}
if (length <= nLimit) {
break;
} else {
nType++;
}
}
if (nType > QRCodeLimitLength.length) {
throw new Error("Too long data");
}
return nType;
}
function _getUTF8Length(sText) {
var replacedText = encodeURI(sText).toString().replace(/\%[0-9a-fA-F]{2}/g, 'a');
return replacedText.length + (replacedText.length != sText ? 3 : 0);
}
function QR8bitByte(data) {
this.mode = QRMode.MODE_8BIT_BYTE;
this.data = data;
this.parsedData = [];
// Added to support UTF-8 Characters
for (var i = 0, l = this.data.length; i < l; i++) {
var byteArray = [];
var code = this.data.charCodeAt(i);
if (code > 0x10000) {
byteArray[0] = 0xF0 | ((code & 0x1C0000) >>> 18);
byteArray[1] = 0x80 | ((code & 0x3F000) >>> 12);
byteArray[2] = 0x80 | ((code & 0xFC0) >>> 6);
byteArray[3] = 0x80 | (code & 0x3F);
} else if (code > 0x800) {
byteArray[0] = 0xE0 | ((code & 0xF000) >>> 12);
byteArray[1] = 0x80 | ((code & 0xFC0) >>> 6);
byteArray[2] = 0x80 | (code & 0x3F);
} else if (code > 0x80) {
byteArray[0] = 0xC0 | ((code & 0x7C0) >>> 6);
byteArray[1] = 0x80 | (code & 0x3F);
} else {
byteArray[0] = code;
}
this.parsedData.push(byteArray);
}
this.parsedData = Array.prototype.concat.apply([], this.parsedData);
if (this.parsedData.length != this.data.length) {
this.parsedData.unshift(191);
this.parsedData.unshift(187);
this.parsedData.unshift(239);
}
}
QR8bitByte.prototype = {
getLength: function (buffer) {
return this.parsedData.length;
},
write: function (buffer) {
for (var i = 0, l = this.parsedData.length; i < l; i++) {
buffer.put(this.parsedData[i], 8);
}
}
};
// QRCodeModel
function QRCodeModel(typeNumber, errorCorrectLevel) {
this.typeNumber = typeNumber;
this.errorCorrectLevel = errorCorrectLevel;
this.modules = null;
this.moduleCount = 0;
this.dataCache = null;
this.dataList = [];
}
QRCodeModel.prototype = {
addData: function (data) { var newData = new QR8bitByte(data); this.dataList.push(newData); this.dataCache = null; }, isDark: function (row, col) {
if (row < 0 || this.moduleCount <= row || col < 0 || this.moduleCount <= col) { throw new Error(row + "," + col); }
return this.modules[row][col];
}, getModuleCount: function () { return this.moduleCount; }, make: function () { this.makeImpl(false, this.getBestMaskPattern()); }, makeImpl: function (test, maskPattern) {
this.moduleCount = this.typeNumber * 4 + 17; this.modules = new Array(this.moduleCount); for (var row = 0; row < this.moduleCount; row++) { this.modules[row] = new Array(this.moduleCount); for (var col = 0; col < this.moduleCount; col++) { this.modules[row][col] = null; } }
this.setupPositionProbePattern(0, 0); this.setupPositionProbePattern(this.moduleCount - 7, 0); this.setupPositionProbePattern(0, this.moduleCount - 7); this.setupPositionAdjustPattern(); this.setupTimingPattern(); this.setupTypeInfo(test, maskPattern); if (this.typeNumber >= 7) { this.setupTypeNumber(test); }
if (this.dataCache == null) { this.dataCache = QRCodeModel.createData(this.typeNumber, this.errorCorrectLevel, this.dataList); }
this.mapData(this.dataCache, maskPattern);
}, setupPositionProbePattern: function (row, col) { for (var r = -1; r <= 7; r++) { if (row + r <= -1 || this.moduleCount <= row + r) continue; for (var c = -1; c <= 7; c++) { if (col + c <= -1 || this.moduleCount <= col + c) continue; if ((0 <= r && r <= 6 && (c == 0 || c == 6)) || (0 <= c && c <= 6 && (r == 0 || r == 6)) || (2 <= r && r <= 4 && 2 <= c && c <= 4)) { this.modules[row + r][col + c] = true; } else { this.modules[row + r][col + c] = false; } } } }, getBestMaskPattern: function () {
var minLostPoint = 0; var pattern = 0; for (var i = 0; i < 8; i++) { this.makeImpl(true, i); var lostPoint = QRUtil.getLostPoint(this); if (i == 0 || minLostPoint > lostPoint) { minLostPoint = lostPoint; pattern = i; } }
return pattern;
}, createMovieClip: function (target_mc, instance_name, depth) {
var qr_mc = target_mc.createEmptyMovieClip(instance_name, depth); var cs = 1; this.make(); for (var row = 0; row < this.modules.length; row++) { var y = row * cs; for (var col = 0; col < this.modules[row].length; col++) { var x = col * cs; var dark = this.modules[row][col]; if (dark) { qr_mc.beginFill(0, 100); qr_mc.moveTo(x, y); qr_mc.lineTo(x + cs, y); qr_mc.lineTo(x + cs, y + cs); qr_mc.lineTo(x, y + cs); qr_mc.endFill(); } } }
return qr_mc;
}, setupTimingPattern: function () {
for (var r = 8; r < this.moduleCount - 8; r++) {
if (this.modules[r][6] != null) { continue; }
this.modules[r][6] = (r % 2 == 0);
}
for (var c = 8; c < this.moduleCount - 8; c++) {
if (this.modules[6][c] != null) { continue; }
this.modules[6][c] = (c % 2 == 0);
}
}, setupPositionAdjustPattern: function () {
var pos = QRUtil.getPatternPosition(this.typeNumber); for (var i = 0; i < pos.length; i++) {
for (var j = 0; j < pos.length; j++) {
var row = pos[i]; var col = pos[j]; if (this.modules[row][col] != null) { continue; }
for (var r = -2; r <= 2; r++) { for (var c = -2; c <= 2; c++) { if (r == -2 || r == 2 || c == -2 || c == 2 || (r == 0 && c == 0)) { this.modules[row + r][col + c] = true; } else { this.modules[row + r][col + c] = false; } } }
}
}
}, setupTypeNumber: function (test) {
var bits = QRUtil.getBCHTypeNumber(this.typeNumber); for (var i = 0; i < 18; i++) { var mod = (!test && ((bits >> i) & 1) == 1); this.modules[Math.floor(i / 3)][i % 3 + this.moduleCount - 8 - 3] = mod; }
for (var i = 0; i < 18; i++) { var mod = (!test && ((bits >> i) & 1) == 1); this.modules[i % 3 + this.moduleCount - 8 - 3][Math.floor(i / 3)] = mod; }
}, setupTypeInfo: function (test, maskPattern) {
var data = (this.errorCorrectLevel << 3) | maskPattern; var bits = QRUtil.getBCHTypeInfo(data); for (var i = 0; i < 15; i++) { var mod = (!test && ((bits >> i) & 1) == 1); if (i < 6) { this.modules[i][8] = mod; } else if (i < 8) { this.modules[i + 1][8] = mod; } else { this.modules[this.moduleCount - 15 + i][8] = mod; } }
for (var i = 0; i < 15; i++) { var mod = (!test && ((bits >> i) & 1) == 1); if (i < 8) { this.modules[8][this.moduleCount - i - 1] = mod; } else if (i < 9) { this.modules[8][15 - i - 1 + 1] = mod; } else { this.modules[8][15 - i - 1] = mod; } }
this.modules[this.moduleCount - 8][8] = (!test);
}, mapData: function (data, maskPattern) {
var inc = -1; var row = this.moduleCount - 1; var bitIndex = 7; var byteIndex = 0; for (var col = this.moduleCount - 1; col > 0; col -= 2) {
if (col == 6) col--; while (true) {
for (var c = 0; c < 2; c++) {
if (this.modules[row][col - c] == null) {
var dark = false; if (byteIndex < data.length) { dark = (((data[byteIndex] >>> bitIndex) & 1) == 1); }
var mask = QRUtil.getMask(maskPattern, row, col - c); if (mask) { dark = !dark; }
this.modules[row][col - c] = dark; bitIndex--; if (bitIndex == -1) { byteIndex++; bitIndex = 7; }
}
}
row += inc; if (row < 0 || this.moduleCount <= row) { row -= inc; inc = -inc; break; }
}
}
}
};
QRCodeModel.PAD0 = 0xEC;
QRCodeModel.PAD1 = 0x11;
QRCodeModel.createData = function (typeNumber, errorCorrectLevel, dataList) {
var rsBlocks = QRRSBlock.getRSBlocks(typeNumber, errorCorrectLevel); var buffer = new QRBitBuffer(); for (var i = 0; i < dataList.length; i++) { var data = dataList[i]; buffer.put(data.mode, 4); buffer.put(data.getLength(), QRUtil.getLengthInBits(data.mode, typeNumber)); data.write(buffer); }
var totalDataCount = 0; for (var i = 0; i < rsBlocks.length; i++) { totalDataCount += rsBlocks[i].dataCount; }
if (buffer.getLengthInBits() > totalDataCount * 8) {
throw new Error("code length overflow. ("
+ buffer.getLengthInBits()
+ ">"
+ totalDataCount * 8
+ ")");
}
if (buffer.getLengthInBits() + 4 <= totalDataCount * 8) { buffer.put(0, 4); }
while (buffer.getLengthInBits() % 8 != 0) { buffer.putBit(false); }
while (true) {
if (buffer.getLengthInBits() >= totalDataCount * 8) { break; }
buffer.put(QRCodeModel.PAD0, 8); if (buffer.getLengthInBits() >= totalDataCount * 8) { break; }
buffer.put(QRCodeModel.PAD1, 8);
}
return QRCodeModel.createBytes(buffer, rsBlocks);
};
QRCodeModel.createBytes = function (buffer, rsBlocks) {
var offset = 0; var maxDcCount = 0; var maxEcCount = 0; var dcdata = new Array(rsBlocks.length); var ecdata = new Array(rsBlocks.length); for (var r = 0; r < rsBlocks.length; r++) {
var dcCount = rsBlocks[r].dataCount; var ecCount = rsBlocks[r].totalCount - dcCount; maxDcCount = Math.max(maxDcCount, dcCount); maxEcCount = Math.max(maxEcCount, ecCount); dcdata[r] = new Array(dcCount); for (var i = 0; i < dcdata[r].length; i++) { dcdata[r][i] = 0xff & buffer.buffer[i + offset]; }
offset += dcCount; var rsPoly = QRUtil.getErrorC...点击查看剩余70%
by thinkfuture
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