//canvas繪制部分代碼：var picurl = "http://wx.qlogo.cn/mmopen/OicsrgN57fqDxImI3icnMeSXRfVUQRueHcxRRuWG0O1Ea1bNyBPKKKLeq5FiaXFWOdsltVe1R1PtJ2EtsDHYDjHgQ/0";   var img = new Image,    canvas = document.createElement("canvas"),    ctx = canvas.getContext("2d"),      //后臺nigix代理 參見問題2      src = picurl.replace("http://wx.qlogo.cn","//wq.jd.com");      //解決 canvas 跨域 toDataURL不能讀取問題 參見問題1      img.crossOrigin = "Anonymous";      //圖片資源的預加載       img.onload = function() {             canvas.width = img.width;            canvas.height = img.height;             ctx.drawImage( img, 0, 0 );            //將畫好的base64圖片             localStorage.setItem( "savedImageData", canvas.toDataURL("image/png") );      }       img.src = src;

// 上傳圖片 參見問題3$.ajax({    type: 'POST',    url:  loadJs.addToken('http://wq.jd.com/activetmp/promotepic/promoteaddpic', "j132"),    data: {        filename: new Date().getTime()+''+Math.floor(Math.random()*10000) + '.jpg',        content: base64pic,        active: "shotpic20160901"    },    dataType: 'json',    xhrFields: { withCredentials: true },    success: function(data) {                           if (picdata.id == 1 && picdata.msg) {                                    //圖片路徑 此前綴路徑的圖片最清晰 參見問題4                                    var imgPre = 'http://img10.360buyimg.com/promotepic/';                                    //圖片地址拼接的完整地址鏈接                                    var photo = imgPre + picdata.msg;                                    $("#cardImg")[0].onload = function() {                                             //to do 業務邏輯                                    };                                    $("#cardImg").attr("src",photo);                           }    },    error:function(data){    }});