<div class="free-upload">    <p>上传您的约会照片，一张合影、一张票据哦！</p>    <div class="free-upload-photo">        <span id="photo_img"></span>            <input type="file" id="photo" />        </div>        <div class="free-upload-bill">            <span id="bill_img"></span>        <input type="file" id="bill" />    </div>    <p id="photo_loading">正在上传...</p></div>

var photo = $(‘#photo‘);function isCanvasSupported(){    var elem = document.createElement(‘canvas‘);    return !!(elem.getContext && elem.getContext(‘2d‘));}photo.on(‘change‘, function(event){    if(!canvasSupported){        return;　　}　　　　　　    compress(event, function(base64Img){　　　　　　$.ajax({　　　　　　‘url‘ : ‘/?s=free/upload‘,　　　　　　‘type‘ : ‘post‘,　　　　　　‘data‘ : {‘base64Img‘ : base64Img},　　    	  ‘success‘ : function(ret){　　　　	             //拿到php传过来的图片地址　　　　　   }　　　　　});　　　});});function compress(event, callback){    var file = event.currentTarget.files[0];    var reader = new FileReader();    reader.onload = function (e) {        var image = $(‘<img/>‘);        image.on(‘load‘, function () {             var square = 700;             var canvas = document.createElement(‘canvas‘);             canvas.width = square;             canvas.height = square;             var context = canvas.getContext(‘2d‘);             context.clearRect(0, 0, square, square);             var imageWidth;             var imageHeight;             var offsetX = 0;             var offsetY = 0;            if (this.width > this.height) {                  imageWidth = Math.round(square * this.width / this.height);                  imageHeight = square;                 offsetX = - Math.round((imageWidth - square) / 2);           } else {                 imageHeight = Math.round(square * this.height / this.width);                 imageWidth = square;                  offsetY = - Math.round((imageHeight - square) / 2);            }            context.drawImage(this, offsetX, offsetY, imageWidth, imageHeight);            var data = http://www.mamicode.com/canvas.toDataURL(‘image/jpeg‘);>