使用jquery组件qrcode生成二维码及应用指南

<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="jquery.qrcode.min.js"></script>

<div id="qrcode"></div>

$("#qrcode").qcrode("需要生成的页面

$("#qrcode").qcrode({
    render: "table",
    width: 200,
    height: 200,
    text: ""
});

function toUtf8(str) {   
    var out, i, len, c;   
    out = "";   
    len = str.length;   
    for(i = 0; i < len; i++) {   
        c = str.charCodeAt(i);   
        if ((c >= 0x0001) && (c <= 0x007F)) {   
            out += str.charAt(i);   
        } else if (c > 0x07FF) {   
            out += String.fromCharCode(0xE0 | ((c >> 12) & 0x0F));   
            out += String.fromCharCode(0x80 | ((c >>  6) & 0x3F));   
            out += String.fromCharCode(0x80 | ((c >>  0) & 0x3F));   
        } else {   
            out += String.fromCharCode(0xC0 | ((c >>  6) & 0x1F));   
            out += String.fromCharCode(0x80 | ((c >>  0) & 0x3F));   
        }   
    }   
    return out;   
}

function download(canvasElem, filename, imageType) {
    var event, saveLink, imageData, defalutImageType;
    defalutImageType = 'png';//定义默认图片类型
    imageData = canvasElem.toDataURL(imageType || defalutImageType);//将canvas元素转化为image data
    saveLink = document.createElementNS('http://.w3./1999/xhtml', 'a');
    saveLink.href = imageData;
    saveLink.download = filename;
    event = document.createEvent('MouseEvents');
    event.initMouseEvent('click', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
    saveLink.dispatchEvent(event);
};

var appModule = angular.module('app', []);
appModule.directive('qrcode', function() {
    return {
        restrict: "A",
        scope: {
          text    : '=',
          options : '='
        },
        link: function(scope, elem, attrs) {
          var $elem, options;
          $elem = $(elem);
          options = { //获取元素的宽度和高度
            width: $elem.width(),
            height: $elem.height()
          };
          angular.extend(options, scope.options);
          scope.$watch('text', function(newText) {
            if (newText) {
              options.text = newText;
              $(elem).qrcode(options);//重新生成二维码
            }
          });
        };
    };
});