/* 2015-09-28 上传图片*/ function convertImgToBase64(url, callback, outputFormat){ var canvas = document.createElement('CANVAS'); var ctx = canvas.getContext('2d'); var img = new Image; img.crossOrigin = 'Anonymous'; img.onload = function(){ var width = img.width; var height = img.height; // 按比例压缩4倍 var rate = (width<height ? width/height : height/width)/4; canvas.width = width*rate; canvas.height = height*rate; ctx.drawImage(img,0,0,width,height,0,0,width*rate,height*rate); var dataURL = canvas.toDataURL(outputFormat || 'image/png'); callback.call(this, dataURL); canvas = null; }; img.src = url; } function getObjectURL(file) { var url = null ; if (window.createObjectURL!=undefined) { // basic url = window.createObjectURL(file) ; } else if (window.URL!=undefined) { // mozilla(firefox) url = window.URL.createObjectURL(file) ; } else if (window.webkitURL!=undefined) { // web_kit or chrome url = window.webkitURL.createObjectURL(file) ; } return url ; } // 前端只需要给input file绑定这个change事件即可(上面两个方法不用管)huodong-msg为input class $('.huodong-msg').bind('change',function(event){ var imageUrl = getObjectURL($(this)[0].files[0]); convertImgToBase64(imageUrl, function(base64Img){ // base64Img为转好的base64,放在img src直接前台展示(<img src="data:image/jpg;base64,/9j/4QMZRXh...." />) alert(base64Img); // base64转图片不需要base64的前缀data:image/jpg;base64 alert(base64Img.split(",")[1]); }); event.preventDefault(); }); /* 2015-09-28 */