往常我们二维码可能都是后端去处理，构建一个image对象，最后输出image二进制流，然后前端定义一个img 控件去展示。
但这有个弊端，就是流传输的比较大，当流量大的时候，不仅浪费流量，而且还会严重影响服务器的性能。
所以本文介绍一种方式后端只提供相关json格式的数据即可，图片在前端进行生成。
参考 http://code.ciaoca.com/javascript/qrcode/
在前端，我们将用到这一个js插件。
QRCode.js 是一个用于生成二维码图片的插件，开源协议为MIT。
github地址：https://github.com/davidshimjs/qrcodejs
首先下载qrcode.js并引用
<script src="qrcode.js"></script>
DOM 结构
<div id="qrcode"></div>
调用
// 简单方式new QRCode(document.getElementById('qrcode'), 'your content');// 设置参数方式var qrcode = new QRCode('qrcode', {text: 'your content',width: 256,height: 256,colorDark : '#000000',colorLight : '#ffffff',correctLevel : QRCode.CorrectLevel.H});// 使用 APIqrcode.clear();qrcode.makeCode('new content');
这样就能生成一个二维码了
参数说明：
new QRCode(element, option)| 名称 | 默认值 | 说明 |
|---|---|---|
| element | – | 显示二维码的元素或该元素的 ID |
| option | 参数配置 |
option 参数说明
| 名称 | 默认值 | 说明 |
|---|---|---|
| width | 256 | 图像宽度 |
| height | 256 | 图像高度 |
| typeNumber | 4 | |
| colorDark | “#000000” | 前景色 |
| colorLight | “#ffffff” | 背景色 |
| correctLevel | QRCode.CorrectLevel.L | 容错级别，可设置为：
QRCode.CorrectLevel.L QRCode.CorrectLevel.M QRCode.CorrectLevel.Q QRCode.CorrectLevel.H |
API 接口：
| 名称 | 说明 |
|---|---|
| makeCode(text) | 设置二维码内容 |
| clear() | 清除二维码。（仅在不支持 Canvas 的浏览器下有效） |
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附 js 源码：
/** * @fileoverview * - Using the 'QRCode for Javascript library' * - Fixed dataset of 'QRCode for Javascript library' for support full-spec. * - this library has no dependencies. * * @author davidshimjs * @see <a href="http://www.d-project.com/" target="_blank">http://www.d-project.com/</a> * @see <a href="http://jeromeetienne.github.com/jquery-qrcode/" target="_blank">http://jeromeetienne.github.com/jquery-qrcode/</a> */ var QRCode; (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 // //--------------------------------------------------------------------- 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); } } }; function QRCodeModel(typeNumber, errorCorrectLevel) { this.typeNumber = typeNumber; this.errorCorrectLevel = errorCorrectLevel; this.modules = null; this.moduleCount = 0; this.dataCache = null; this.dataList = []; } QRCodeModel.prototype={addData:function(data){var newData=new QR8bitByte(data);this.dataList.push(newData);this.dataCache=null;},isDark:function(row,col){if(row<0||this.moduleCount<=row||col<0||this.moduleCount<=col){throw new Error(row+","+col);} return this.modules[row][col];},getModuleCount:function(){return this.moduleCount;},make:function(){this.makeImpl(false,this.getBestMaskPattern());},makeImpl:function(test,maskPattern){this.moduleCount=this.typeNumber*4+17;this.modules=new Array(this.moduleCount);for(var row=0;row<this.moduleCount;row++){this.modules[row]=new Array(this.moduleCount);for(var col=0;col<this.moduleCount;col++){this.modules[row][col]=null;}} this.setupPositionProbePattern(0,0);this.setupPositionProbePattern(this.moduleCount-7,0);this.setupPositionProbePattern(0,this.moduleCount-7);this.setupPositionAdjustPattern();this.setupTimingPattern();this.setupTypeInfo(test,maskPattern);if(this.typeNumber>=7){this.setupTypeNumber(test);} if(this.dataCache==null){this.dataCache=QRCodeModel.createData(this.typeNumber,this.errorCorrectLevel,this.dataList);} this.mapData(this.dataCache,maskPattern);},setupPositionProbePattern:function(row,col){for(var r=-1;r<=7;r++){if(row+r<=-1||this.moduleCount<=row+r)continue;for(var c=-1;c<=7;c++){if(col+c<=-1||this.moduleCount<=col+c)continue;if((0<=r&&r<=6&&(c==0||c==6))||(0<=c&&c<=6&&(r==0||r==6))||(2<=r&&r<=4&&2<=c&&c<=4)){this.modules[row+r][col+c]=true;}else{this.modules[row+r][col+c]=false;}}}},getBestMaskPattern:function(){var minLostPoint=0;var pattern=0;for(var i=0;i<8;i++){this.makeImpl(true,i);var lostPoint=QRUtil.getLostPoint(this);if(i==0||minLostPoint>lostPoint){minLostPoint=lostPoint;pattern=i;}} return pattern;},createMovieClip:function(target_mc,instance_name,depth){var qr_mc=target_mc.createEmptyMovieClip(instance_name,depth);var cs=1;this.make();for(var row=0;row<this.modules.length;row++){var y=row*cs;for(var col=0;col<this.modules[row].length;col++){var x=col*cs;var dark=this.modules[row][col];if(dark){qr_mc.beginFill(0,100);qr_mc.moveTo(x,y);qr_mc.lineTo(x+cs,y);qr_mc.lineTo(x+cs,y+cs);qr_mc.lineTo(x,y+cs);qr_mc.endFill();}}} return qr_mc;},setupTimingPattern:function(){for(var r=8;r<this.moduleCount-8;r++){if(this.modules[r][6]!=null){continue;} this.modules[r][6]=(r%2==0);} for(var c=8;c<this.moduleCount-8;c++){if(this.modules[6][c]!=null){continue;} this.modules[6][c]=(c%2==0);}},setupPositionAdjustPattern:function(){var pos=QRUtil.getPatternPosition(this.typeNumber);for(var i=0;i<pos.length;i++){for(var j=0;j<pos.length;j++){var row=pos[i];var col=pos[j];if(this.modules[row][col]!=null){continue;} for(var r=-2;r<=2;r++){for(var c=-2;c<=2;c++){if(r==-2||r==2||c==-2||c==2||(r==0&&c==0)){this.modules[row+r][col+c]=true;}else{this.modules[row+r][col+c]=false;}}}}}},setupTypeNumber:function(test){var bits=QRUtil.getBCHTypeNumber(this.typeNumber);for(var i=0;i<18;i++){var mod=(!test&&((bits>>i)&1)==1);this.modules[Math.floor(i/3)][i%3+this.moduleCount-8-3]=mod;} for(var i=0;i<18;i++){var mod=(!test&&((bits>>i)&1)==1);this.modules[i%3+this.moduleCount-8-3][Math.floor(i/3)]=mod;}},setupTypeInfo:function(test,maskPattern){var data=(this.errorCorrectLevel<<3)|maskPattern;var bits=QRUtil.getBCHTypeInfo(data);for(var i=0;i<15;i++){var mod=(!test&&((bits>>i)&1)==1);if(i<6){this.modules[i][8]=mod;}else if(i<8){this.modules[i+1][8]=mod;}else{this.modules[this.moduleCount-15+i][8]=mod;}} for(var i=0;i<15;i++){var mod=(!test&&((bits>>i)&1)==1);if(i<8){this.modules[8][this.moduleCount-i-1]=mod;}else if(i<9){this.modules[8][15-i-1+1]=mod;}else{this.modules[8][15-i-1]=mod;}} this.modules[this.moduleCount-8][8]=(!test);},mapData:function(data,maskPattern){var inc=-1;var row=this.moduleCount-1;var bitIndex=7;var byteIndex=0;for(var col=this.moduleCount-1;col>0;col-=2){if(col==6)col--;while(true){for(var c=0;c<2;c++){if(this.modules[row][col-c]==null){var dark=false;if(byteIndex<data.length){dark=(((data[byteIndex]>>>bitIndex)&1)==1);} var mask=QRUtil.getMask(maskPattern,row,col-c);if(mask){dark=!dark;} this.modules[row][col-c]=dark;bitIndex--;if(bitIndex==-1){byteIndex++;bitIndex=7;}}} row+=inc;if(row<0||this.moduleCount<=row){row-=inc;inc=-inc;break;}}}}};QRCodeModel.PAD0=0xEC;QRCodeModel.PAD1=0x11;QRCodeModel.createData=function(typeNumber,errorCorrectLevel,dataList){var rsBlocks=QRRSBlock.getRSBlocks(typeNumber,errorCorrectLevel);var buffer=new QRBitBuffer();for(var i=0;i<dataList.length;i++){var data=dataList[i];buffer.put(data.mode,4);buffer.put(data.getLength(),QRUtil.getLengthInBits(data.mode,typeNumber));data.write(buffer);} var totalDataCount=0;for(var i=0;i<rsBlocks.length;i++){totalDataCount+=rsBlocks[i].dataCount;} if(buffer.getLengthInBits()>totalDataCount*8){throw new Error("code length overflow. (" +buffer.getLengthInBits() +">" +totalDataCount*8 +")");} if(buffer.getLengthInBits()+4<=totalDataCount*8){buffer.put(0,4);} while(buffer.getLengthInBits()%8!=0){buffer.putBit(false);} while(true){if(buffer.getLengthInBits()>=totalDataCount*8){break;} buffer.put(QRCodeModel.PAD0,8);if(buffer.getLengthInBits()>=totalDataCount*8){break;} buffer.put(QRCodeModel.PAD1,8);} return QRCodeModel.createBytes(buffer,rsBlocks);};QRCodeModel.createBytes=function(buffer,rsBlocks){var offset=0;var maxDcCount=0;var maxEcCount=0;var dcdata=new Array(rsBlocks.length);var ecdata=new Array(rsBlocks.length);for(var r=0;r<rsBlocks.length;r++){var dcCount=rsBlocks[r].dataCount;var ecCount=rsBlocks[r].totalCount-dcCount;maxDcCount=Math.max(maxDcCount,dcCount);maxEcCount=Math.max(maxEcCount,ecCount);dcdata[r]=new Array(dcCount);for(var i=0;i<dcdata[r].length;i++){dcdata[r][i]=0xff&buffer.buffer[i+offset];} offset+=dcCount;var rsPoly=QRUtil.getErrorCorrectPolynomial(ecCount);var rawPoly=new QRPolynomial(dcdata[r],rsPoly.getLength()-1);var modPoly=rawPoly.mod(rsPoly);ecdata[r]=new Array(rsPoly.getLength()-1);for(var i=0;i<ecdata[r].length;i++){var modIndex=i+modPoly.getLength()-ecdata[r].length;ecdata[r][i]=(modIndex>=0)?modPoly.get(modIndex):0;}} var totalCodeCount=0;for(var i=0;i<rsBlocks.length;i++){totalCodeCount+=rsBlocks[i].totalCount;} var data=new Array(totalCodeCount);var index=0;for(var i=0;i<maxDcCount;i++){for(var r=0;r<rsBlocks.length;r++){if(i<dcdata[r].length){data[index++]=dcdata[r][i];}}} for(var i=0;i<maxEcCount;i++){for(var r=0;r<rsBlocks.length;r++){if(i<ecdata[r].length){data[index++]=ecdata[r][i];}}} return data;};var QRMode={MODE_NUMBER:1<<0,MODE_ALPHA_NUM:1<<1,MODE_8BIT_BYTE:1<<2,MODE_KANJI:1<<3};var QRErrorCorrectLevel={L:1,M:0,Q:3,H:2};var QRMaskPattern={PATTERN000:0,PATTERN001:1,PATTERN010:2,PATTERN011:3,PATTERN100:4,PATTERN101:5,PATTERN110:6,PATTERN111:7};var QRUtil={PATTERN_POSITION_TABLE:[[],[6,18],[6,22],[6,26],[6,30],[6,34],[6,22,38],[6,24,42],[6,26,46],[6,28,50],[6,30,54],[6,32,58],[6,34,62],[6,26,46,66],[6,26,48,70],[6,26,50,74],[6,30,54,78],[6,30,56,82],[6,30,58,86],[6,34,62,90],[6,28,50,72,94],[6,26,50,74,98],[6,30,54,78,102],[6,28,54,80,106],[6,32,58,84,110],[6,30,58,86,114],[6,34,62,90,118],[6,26,50,74,98,122],[6,30,54,78,102,126],[6,26,52,78,104,130],[6,30,56,82,108,134],[6,34,60,86,112,138],[6,30,58,86,114,142],[6,34,62,90,118,146],[6,30,54,78,102,126,150],[6,24,50,76,102,128,154],[6,28,54,80,106,132,158],[6,32,58,84,110,136,162],[6,26,54,82,110,138,166],[6,30,58,86,114,142,170]],G15:(1<<10)|(1<<8)|(1<<5)|(1<<4)|(1<<2)|(1<<1)|(1<<0),G18:(1<<12)|(1<<11)|(1<<10)|(1<<9)|(1<<8)|(1<<5)|(1<<2)|(1<<0),G15_MASK:(1<<14)|(1<<12)|(1<<10)|(1<<4)|(1<<1),getBCHTypeInfo:function(data){var d=data<<10;while(QRUtil.getBCHDigit(d)-QRUtil.getBCHDigit(QRUtil.G15)>=0){d^=(QRUtil.G15<<(QRUtil.getBCHDigit(d)-QRUtil.getBCHDigit(QRUtil.G15)));} return((data<<10)|d)^QRUtil.G15_MASK;},getBCHTypeNumber:function(data){var d=data<<12;while(QRUtil.getBCHDigit(d)-QRUtil.getBCHDigit(QRUtil.G18)>=0){d^=(QRUtil.G18<<(QRUtil.getBCHDigit(d)-QRUtil.getBCHDigit(QRUtil.G18)));} return(data<<12)|d;},getBCHDigit:function(data){var digit=0;while(data!=0){digit++;data>>>=1;} return digit;},getPatternPosition:function(typeNumber){return QRUtil.PATTERN_POSITION_TABLE[typeNumber-1];},getMask:function(maskPattern,i,j){switch(maskPattern){case QRMaskPattern.PATTERN000:return(i+j)%2==0;case QRMaskPattern.PATTERN001:return i%2==0;case QRMaskPattern.PATTERN010:return j%3==0;case QRMaskPattern.PATTERN011:return(i+j)%3==0;case QRMaskPattern.PATTERN100:return(Math.floor(i/2)+Math.floor(j/3))%2==0;case QRMaskPattern.PATTERN101:return(i*j)%2+(i*j)%3==0;case QRMaskPattern.PATTERN110:return((i*j)%2+(i*j)%3)%2==0;case QRMaskPattern.PATTERN111:return((i*j)%3+(i+j)%2)%2==0;default:throw new Error("bad maskPattern:"+maskPattern);}},getErrorCorrectPolynomial:function(errorCorrectLength){var a=new QRPolynomial([1],0);for(var i=0;i<errorCorrectLength;i++){a=a.multiply(new QRPolynomial([1,QRMath.gexp(i)],0));} return a;},getLengthInBits:function(mode,type){if(1<=type&&type<10){switch(mode){case QRMode.MODE_NUMBER:return 10;case QRMode.MODE_ALPHA_NUM:return 9;case QRMode.MODE_8BIT_BYTE:return 8;case QRMode.MODE_KANJI:return 8;default:throw new Error("mode:"+mode);}}else if(type<27){switch(mode){case QRMode.MODE_NUMBER:return 12;case QRMode.MODE_ALPHA_NUM:return 11;case QRMode.MODE_8BIT_BYTE:return 16;case QRMode.MODE_KANJI:return 10;default:throw new Error("mode:"+mode);}}else if(type<41){switch(mode){case QRMode.MODE_NUMBER:return 14;case QRMode.MODE_ALPHA_NUM:return 13;case QRMode.MODE_8BIT_BYTE:return 16;case QRMode.MODE_KANJI:return 12;default:throw new Error("mode:"+mode);}}else{throw new Error("type:"+type);}},getLostPoint:function(qrCode){var moduleCount=qrCode.getModuleCount();var lostPoint=0;for(var row=0;row<moduleCount;row++){for(var col=0;col<moduleCount;col++){var sameCount=0;var dark=qrCode.isDark(row,col);for(var r=-1;r<=1;r++){if(row+r<0||moduleCount<=row+r){continue;} for(var c=-1;c<=1;c++){if(col+c<0||moduleCount<=col+c){continue;} if(r==0&&c==0){continue;} if(dark==qrCode.isDark(row+r,col+c)){sameCount++;}}} if(sameCount>5){lostPoint+=(3+sameCount-5);}}} for(var row=0;row<moduleCount-1;row++){for(var col=0;col<moduleCount-1;col++){var count=0;if(qrCode.isDark(row,col))count++;if(qrCode.isDark(row+1,col))count++;if(qrCode.isDark(row,col+1))count++;if(qrCode.isDark(row+1,col+1))count++;if(count==0||count==4){lostPoint+=3;}}} for(var row=0;row<moduleCount;row++){for(var col=0;col<moduleCount-6;col++){if(qrCode.isDark(row,col)&&!qrCode.isDark(row,col+1)&&qrCode.isDark(row,col+2)&&qrCode.isDark(row,col+3)&&qrCode.isDark(row,col+4)&&!qrCode.isDark(row,col+5)&&qrCode.isDark(row,col+6)){lostPoint+=40;}}} for(var col=0;col<moduleCount;col++){for(var row=0;row<moduleCount-6;row++){if(qrCode.isDark(row,col)&&!qrCode.isDark(row+1,col)&&qrCode.isDark(row+2,col)&&qrCode.isDark(row+3,col)&&qrCode.isDark(row+4,col)&&!qrCode.isDark(row+5,col)&&qrCode.isDark(row+6,col)){lostPoint+=40;}}} var darkCount=0;for(var col=0;col<moduleCount;col++){for(var row=0;row<moduleCount;row++){if(qrCode.isDark(row,col)){darkCount++;}}} var ratio=Math.abs(100*darkCount/moduleCount/moduleCount-50)/5;lostPoint+=ratio*10;return lostPoint;}};var QRMath={glog:function(n){if(n<1){throw new Error("glog("+n+")");} return QRMath.LOG_TABLE[n];},gexp:function(n){while(n<0){n+=255;} while(n>=256){n-=255;} return QRMath.EXP_TABLE[n];},EXP_TABLE:new Array(256),LOG_TABLE:new Array(256)};for(var i=0;i<8;i++){QRMath.EXP_TABLE[i]=1<<i;} for(var i=8;i<256;i++){QRMath.EXP_TABLE[i]=QRMath.EXP_TABLE[i-4]^QRMath.EXP_TABLE[i-5]^QRMath.EXP_TABLE[i-6]^QRMath.EXP_TABLE[i-8];} for(var i=0;i<255;i++){QRMath.LOG_TABLE[QRMath.EXP_TABLE[i]]=i;} function QRPolynomial(num,shift){if(num.length==undefined){throw new Error(num.length+"/"+shift);} var offset=0;while(offset<num.length&&num[offset]==0){offset++;} this.num=new Array(num.length-offset+shift);for(var i=0;i<num.length-offset;i++){this.num[i]=num[i+offset];}} QRPolynomial.prototype={get:function(index){return this.num[index];},getLength:function(){return this.num.length;},multiply:function(e){var num=new Array(this.getLength()+e.getLength()-1);for(var i=0;i<this.getLength();i++){for(var j=0;j<e.getLength();j++){num[i+j]^=QRMath.gexp(QRMath.glog(this.get(i))+QRMath.glog(e.get(j)));}} return new QRPolynomial(num,0);},mod:function(e){if(this.getLength()-e.getLength()<0){return this;} var ratio=QRMath.glog(this.get(0))-QRMath.glog(e.get(0));var num=new Array(this.getLength());for(var i=0;i<this.getLength();i++){num[i]=this.get(i);} for(var i=0;i<e.getLength();i++){num[i]^=QRMath.gexp(QRMath.glog(e.get(i))+ratio);} return new QRPolynomial(num,0).mod(e);}};function QRRSBlock(totalCount,dataCount){this.totalCount=totalCount;this.dataCount=dataCount;} QRRSBlock.RS_BLOCK_TABLE=[[1,26,19],[1,26,16],[1,26,13],[1,26,9],[1,44,34],[1,44,28],[1,44,22],[1,44,16],[1,70,55],[1,70,44],[2,35,17],[2,35,13],[1,100,80],[2,50,32],[2,50,24],[4,25,9],[1,134,108],[2,67,43],[2,33,15,2,34,16],[2,33,11,2,34,12],[2,86,68],[4,43,27],[4,43,19],[4,43,15],[2,98,78],[4,49,31],[2,32,14,4,33,15],[4,39,13,1,40,14],[2,121,97],[2,60,38,2,61,39],[4,40,18,2,41,19],[4,40,14,2,41,15],[2,146,116],[3,58,36,2,59,37],[4,36,16,4,37,17],[4,36,12,4,37,13],[2,86,68,2,87,69],[4,69,43,1,70,44],[6,43,19,2,44,20],[6,43,15,2,44,16],[4,101,81],[1,80,50,4,81,51],[4,50,22,4,51,23],[3,36,12,8,37,13],[2,116,92,2,117,93],[6,58,36,2,59,37],[4,46,20,6,47,21],[7,42,14,4,43,15],[4,133,107],[8,59,37,1,60,38],[8,44,20,4,45,21],[12,33,11,4,34,12],[3,145,115,1,146,116],[4,64,40,5,65,41],[11,36,16,5,37,17],[11,36,12,5,37,13],[5,109,87,1,110,88],[5,65,41,5,66,42],[5,54,24,7,55,25],[11,36,12],[5,122,98,1,123,99],[7,73,45,3,74,46],[15,43,19,2,44,20],[3,45,15,13,46,16],[1,135,107,5,136,108],[10,74,46,1,75,47],[1,50,22,15,51,23],[2,42,14,17,43,15],[5,150,120,1,151,121],[9,69,43,4,70,44],[17,50,22,1,51,23],[2,42,14,19,43,15],[3,141,113,4,142,114],[3,70,44,11,71,45],[17,47,21,4,48,22],[9,39,13,16,40,14],[3,135,107,5,136,108],[3,67,41,13,68,42],[15,54,24,5,55,25],[15,43,15,10,44,16],[4,144,116,4,145,117],[17,68,42],[17,50,22,6,51,23],[19,46,16,6,47,17],[2,139,111,7,140,112],[17,74,46],[7,54,24,16,55,25],[34,37,13],[4,151,121,5,152,122],[4,75,47,14,76,48],[11,54,24,14,55,25],[16,45,15,14,46,16],[6,147,117,4,148,118],[6,73,45,14,74,46],[11,54,24,16,55,25],[30,46,16,2,47,17],[8,132,106,4,133,107],[8,75,47,13,76,48],[7,54,24,22,55,25],[22,45,15,13,46,16],[10,142,114,2,143,115],[19,74,46,4,75,47],[28,50,22,6,51,23],[33,46,16,4,47,17],[8,152,122,4,153,123],[22,73,45,3,74,46],[8,53,23,26,54,24],[12,45,15,28,46,16],[3,147,117,10,148,118],[3,73,45,23,74,46],[4,54,24,31,55,25],[11,45,15,31,46,16],[7,146,116,7,147,117],[21,73,45,7,74,46],[1,53,23,37,54,24],[19,45,15,26,46,16],[5,145,115,10,146,116],[19,75,47,10,76,48],[15,54,24,25,55,25],[23,45,15,25,46,16],[13,145,115,3,146,116],[2,74,46,29,75,47],[42,54,24,1,55,25],[23,45,15,28,46,16],[17,145,115],[10,74,46,23,75,47],[10,54,24,35,55,25],[19,45,15,35,46,16],[17,145,115,1,146,116],[14,74,46,21,75,47],[29,54,24,19,55,25],[11,45,15,46,46,16],[13,145,115,6,146,116],[14,74,46,23,75,47],[44,54,24,7,55,25],[59,46,16,1,47,17],[12,151,121,7,152,122],[12,75,47,26,76,48],[39,54,24,14,55,25],[22,45,15,41,46,16],[6,151,121,14,152,122],[6,75,47,34,76,48],[46,54,24,10,55,25],[2,45,15,64,46,16],[17,152,122,4,153,123],[29,74,46,14,75,47],[49,54,24,10,55,25],[24,45,15,46,46,16],[4,152,122,18,153,123],[13,74,46,32,75,47],[48,54,24,14,55,25],[42,45,15,32,46,16],[20,147,117,4,148,118],[40,75,47,7,76,48],[43,54,24,22,55,25],[10,45,15,67,46,16],[19,148,118,6,149,119],[18,75,47,31,76,48],[34,54,24,34,55,25],[20,45,15,61,46,16]];QRRSBlock.getRSBlocks=function(typeNumber,errorCorrectLevel){var rsBlock=QRRSBlock.getRsBlockTable(typeNumber,errorCorrectLevel);if(rsBlock==undefined){throw new Error("bad rs block @ typeNumber:"+typeNumber+"/errorCorrectLevel:"+errorCorrectLevel);} var length=rsBlock.length/3;var list=[];for(var i=0;i<length;i++){var count=rsBlock[i*3+0];var totalCount=rsBlock[i*3+1];var dataCount=rsBlock[i*3+2];for(var j=0;j<count;j++){list.push(new QRRSBlock(totalCount,dataCount));}} return list;};QRRSBlock.getRsBlockTable=function(typeNumber,errorCorrectLevel){switch(errorCorrectLevel){case QRErrorCorrectLevel.L:return QRRSBlock.RS_BLOCK_TABLE[(typeNumber-1)*4+0];case QRErrorCorrectLevel.M:return QRRSBlock.RS_BLOCK_TABLE[(typeNumber-1)*4+1];case QRErrorCorrectLevel.Q:return QRRSBlock.RS_BLOCK_TABLE[(typeNumber-1)*4+2];case QRErrorCorrectLevel.H:return QRRSBlock.RS_BLOCK_TABLE[(typeNumber-1)*4+3];default:return undefined;}};function QRBitBuffer(){this.buffer=[];this.length=0;} QRBitBuffer.prototype={get:function(index){var bufIndex=Math.floor(index/8);return((this.buffer[bufIndex]>>>(7-index%8))&1)==1;},put:function(num,length){for(var i=0;i<length;i++){this.putBit(((num>>>(length-i-1))&1)==1);}},getLengthInBits:function(){return this.length;},putBit:function(bit){var bufIndex=Math.floor(this.length/8);if(this.buffer.length<=bufIndex){this.buffer.push(0);} if(bit){this.buffer[bufIndex]|=(0x80>>>(this.length%8));} this.length++;}};var QRCodeLimitLength=[[17,14,11,7],[32,26,20,14],[53,42,32,24],[78,62,46,34],[106,84,60,44],[134,106,74,58],[154,122,86,64],[192,152,108,84],[230,180,130,98],[271,213,151,119],[321,251,177,137],[367,287,203,155],[425,331,241,177],[458,362,258,194],[520,412,292,220],[586,450,322,250],[644,504,364,280],[718,560,394,310],[792,624,442,338],[858,666,482,382],[929,711,509,403],[1003,779,565,439],[1091,857,611,461],[1171,911,661,511],[1273,997,715,535],[1367,1059,751,593],[1465,1125,805,625],[1528,1190,868,658],[1628,1264,908,698],[1732,1370,982,742],[1840,1452,1030,790],[1952,1538,1112,842],[2068,1628,1168,898],[2188,1722,1228,958],[2303,1809,1283,983],[2431,1911,1351,1051],[2563,1989,1423,1093],[2699,2099,1499,1139],[2809,2213,1579,1219],[2953,2331,1663,1273]]; function _isSupportCanvas() { return typeof CanvasRenderingContext2D != "undefined"; } // android 2.x doesn't support Data-URI spec function _getAndroid() { var android = false; var sAgent = navigator.userAgent; if (/android/i.test(sAgent)) { // android android = true; var aMat = sAgent.toString().match(/android ([0-9]\.[0-9])/i); if (aMat && aMat[1]) { android = parseFloat(aMat[1]); } } return android; } var svgDrawer = (function() { var Drawing = function (el, htOption) { this._el = el; this._htOption = htOption; }; Drawing.prototype.draw = function (oQRCode) { var _htOption = this._htOption; var _el = this._el; var nCount = oQRCode.getModuleCount(); var nWidth = Math.floor(_htOption.width / nCount); var nHeight = Math.floor(_htOption.height / nCount); this.clear(); function makeSVG(tag, attrs) { var el = document.createElementNS('http://www.w3.org/2000/svg', tag); for (var k in attrs) if (attrs.hasOwnProperty(k)) el.setAttribute(k, attrs[k]); return el; } var svg = makeSVG("svg" , {'viewBox': '0 0 ' + String(nCount) + " " + String(nCount), 'width': '100%', 'height': '100%', 'fill': _htOption.colorLight}); svg.setAttributeNS("http://www.w3.org/2000/xmlns/", "xmlns:xlink", "http://www.w3.org/1999/xlink"); _el.appendChild(svg); svg.appendChild(makeSVG("rect", {"fill": _htOption.colorLight, "width": "100%", "height": "100%"})); svg.appendChild(makeSVG("rect", {"fill": _htOption.colorDark, "width": "1", "height": "1", "id": "template"})); for (var row = 0; row < nCount; row++) { for (var col = 0; col < nCount; col++) { if (oQRCode.isDark(row, col)) { var child = makeSVG("use", {"x": String(col), "y": String(row)}); child.setAttributeNS("http://www.w3.org/1999/xlink", "href", "#template") svg.appendChild(child); } } } }; Drawing.prototype.clear = function () { while (this._el.hasChildNodes()) this._el.removeChild(this._el.lastChild); }; return Drawing; })(); var useSVG = document.documentElement.tagName.toLowerCase() === "svg"; // Drawing in DOM by using Table tag var Drawing = useSVG ? svgDrawer : !_isSupportCanvas() ? (function () { var Drawing = function (el, htOption) { this._el = el; this._htOption = htOption; }; /** * Draw the QRCode * * @param {QRCode} oQRCode */ Drawing.prototype.draw = function (oQRCode) { var _htOption = this._htOption; var _el = this._el; var nCount = oQRCode.getModuleCount(); var nWidth = Math.floor(_htOption.width / nCount); var nHeight = Math.floor(_htOption.height / nCount); var aHTML = ['<table style="border:0;border-collapse:collapse;">']; for (var row = 0; row < nCount; row++) { aHTML.push('<tr>'); for (var col = 0; col < nCount; col++) { aHTML.push('<td style="border:0;border-collapse:collapse;padding:0;margin:0;width:' + nWidth + 'px;height:' + nHeight + 'px;background-color:' + (oQRCode.isDark(row, col) ? _htOption.colorDark : _htOption.colorLight) + ';"></td>'); } aHTML.push('</tr>'); } aHTML.push('</table>'); _el.innerHTML = aHTML.join(''); // Fix the margin values as real size. var elTable = _el.childNodes[0]; var nLeftMarginTable = (_htOption.width - elTable.offsetWidth) / 2; var nTopMarginTable = (_htOption.height - elTable.offsetHeight) / 2; if (nLeftMarginTable > 0 && nTopMarginTable > 0) { elTable.style.margin = nTopMarginTable + "px " + nLeftMarginTable + "px"; } }; /** * Clear the QRCode */ Drawing.prototype.clear = function () { this._el.innerHTML = ''; }; return Drawing; })() : (function () { // Drawing in Canvas function _onMakeImage() { this._elImage.src = this._elCanvas.toDataURL("image/png"); this._elImage.style.display = "block"; this._elCanvas.style.display = "none"; } // Android 2.1 bug workaround // http://code.google.com/p/android/issues/detail?id=5141 if (this._android && this._android <= 2.1) { var factor = 1 / window.devicePixelRatio; var drawImage = CanvasRenderingContext2D.prototype.drawImage; CanvasRenderingContext2D.prototype.drawImage = function (image, sx, sy, sw, sh, dx, dy, dw, dh) { if (("nodeName" in image) && /img/i.test(image.nodeName)) { for (var i = arguments.length - 1; i >= 1; i--) { arguments[i] = arguments[i] * factor; } } else if (typeof dw == "undefined") { arguments[1] *= factor; arguments[2] *= factor; arguments[3] *= factor; arguments[4] *= factor; } drawImage.apply(this, arguments); }; } /** * Check whether the user's browser supports Data URI or not * * @private * @param {Function} fSuccess Occurs if it supports Data URI * @param {Function} fFail Occurs if it doesn't support Data URI */ function _safeSetDataURI(fSuccess, fFail) { var self = this; self._fFail = fFail; self._fSuccess = fSuccess; // Check it just once if (self._bSupportDataURI === null) { var el = document.createElement("img"); var fOnError = function() { self._bSupportDataURI = false; if (self._fFail) { self._fFail.call(self); } }; var fOnSuccess = function() { self._bSupportDataURI = true; if (self._fSuccess) { self._fSuccess.call(self); } }; el.onabort = fOnError; el.onerror = fOnError; el.onload = fOnSuccess; el.src = "data:image/gif;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU5ErkJggg=="; // the Image contains 1px data. return; } else if (self._bSupportDataURI === true && self._fSuccess) { self._fSuccess.call(self); } else if (self._bSupportDataURI === false && self._fFail) { self._fFail.call(self); } }; /** * Drawing QRCode by using canvas * * @constructor * @param {HTMLElement} el * @param {Object} htOption QRCode Options */ var Drawing = function (el, htOption) { this._bIsPainted = false; this._android = _getAndroid(); this._htOption = htOption; this._elCanvas = document.createElement("canvas"); this._elCanvas.width = htOption.width; this._elCanvas.height = htOption.height; el.appendChild(this._elCanvas); this._el = el; this._oContext = this._elCanvas.getContext("2d"); this._bIsPainted = false; this._elImage = document.createElement("img"); this._elImage.alt = "Scan me!"; this._elImage.style.display = "none"; this._el.appendChild(this._elImage); this._bSupportDataURI = null; }; /** * Draw the QRCode * * @param {QRCode} oQRCode */ Drawing.prototype.draw = function (oQRCode) { var _elImage = this._elImage; var _oContext = this._oContext; var _htOption = this._htOption; var nCount = oQRCode.getModuleCount(); var nWidth = _htOption.width / nCount; var nHeight = _htOption.height / nCount; var nRoundedWidth = Math.round(nWidth); var nRoundedHeight = Math.round(nHeight); _elImage.style.display = "none"; this.clear(); for (var row = 0; row < nCount; row++) { for (var col = 0; col < nCount; col++) { var bIsDark = oQRCode.isDark(row, col); var nLeft = col * nWidth; var nTop = row * nHeight; _oContext.strokeStyle = bIsDark ? _htOption.colorDark : _htOption.colorLight; _oContext.lineWidth = 1; _oContext.fillStyle = bIsDark ? _htOption.colorDark : _htOption.colorLight; _oContext.fillRect(nLeft, nTop, nWidth, nHeight); // 鞎堩嫲 鞎Μ鞏挫嫳 氚╈ 觳橂Μ _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 ); } } this._bIsPainted = true; }; /** * Make the image from Canvas if the browser supports Data URI. */ Drawing.prototype.makeImage = function () { if (this._bIsPainted) { _safeSetDataURI.call(this, _onMakeImage); } }; /** * Return whether the QRCode is painted or not * * @return {Boolean} */ Drawing.prototype.isPainted = function () { return this._bIsPainted; }; /** * Clear the QRCode */ Drawing.prototype.clear = function () { this._oContext.clearRect(0, 0, this._elCanvas.width, this._elCanvas.height); this._bIsPainted = false; }; /** * @private * @param {Number} nNumber */ Drawing.prototype.round = function (nNumber) { if (!nNumber) { return nNumber; } return Math.floor(nNumber * 1000) / 1000; }; return Drawing; })(); /** * 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); } /** * @class QRCode * @constructor * @example * new QRCode(document.getElementById("test"), "http://jindo.dev.naver.com/collie"); * * @example * var oQRCode = new QRCode("test", { * text : "http://naver.com", * width : 128, * height : 128 * }); * * oQRCode.clear(); // Clear the QRCode. * oQRCode.makeCode("http://map.naver.com"); // Re-create the QRCode. * * @param {HTMLElement|String} el target element or 'id' attribute of element. * @param {Object|String} vOption * @param {String} vOption.text QRCode link data * @param {Number} [vOption.width=256] * @param {Number} [vOption.height=256] * @param {String} [vOption.colorDark="#000000"] * @param {String} [vOption.colorLight="#ffffff"] * @param {QRCode.CorrectLevel} [vOption.correctLevel=QRCode.CorrectLevel.H] [L|M|Q|H] */ QRCode = function (el, 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]; } } if (typeof el == "string") { el = document.getElementById(el); } if (this._htOption.useSVG) { Drawing = svgDrawer; } this._android = _getAndroid(); this._el = el; this._oQRCode = null; this._oDrawing = new Drawing(this._el, this._htOption); if (this._htOption.text) { this.makeCode(this._htOption.text); } }; /** * Make the QRCode * * @param {String} sText link data */ QRCode.prototype.makeCode = function (sText) { this._oQRCode = new QRCodeModel(_getTypeNumber(sText, this._htOption.correctLevel), this._htOption.correctLevel); this._oQRCode.addData(sText); this._oQRCode.make(); this._el.title = sText; this._oDrawing.draw(this._oQRCode); this.makeImage(); }; /** * Make the Image from Canvas element * - It occurs automatically * - Android below 3 doesn't support Data-URI spec. * * @private */ QRCode.prototype.makeImage = function () { if (typeof this._oDrawing.makeImage == "function" && (!this._android || this._android >= 3)) { this._oDrawing.makeImage(); } }; /** * Clear the QRCode */ QRCode.prototype.clear = function () { this._oDrawing.clear(); }; /** * @name QRCode.CorrectLevel */ QRCode.CorrectLevel = QRErrorCorrectLevel; })();
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