<script src="./js/jszip.min.js"></script>
<script src="./js/FileSaver.min.js"></script>
<script src="./jquery/2.1.3/js/jquery.min.js"></script>
<script>
    var zip = new JSZip();
    zip.file("Hello.txt", "Hello World\n");
    var img = zip.folder("images");
    img.file("1.png", getBase64("https://www.baidu.com/img/bd_logo1.png"), {base64: true});
    zip.generateAsync({type: "blob"})
        .then(function (content) {
            // see FileSaver.js
            saveAs(content, "example.zip");
        });


    //传入图片路径，返回base64
    function getBase64(img) {
        function getBase64Image(img, width, height) {//width、height调用时传入具体像素值，控制大小 ,不传则默认图像大小
            var canvas = document.createElement("canvas");
            canvas.width = width ? width : img.width;
            canvas.height = height ? height : img.height;

            var ctx = canvas.getContext("2d");
            ctx.drawImage(img, 0, 0, canvas.width, canvas.height);
            var dataURL = canvas.toDataURL();
            var arr = dataURL.split(",");
            return arr[1];
        }

        var image = new Image();
        image.crossOrigin = 'Anonymous';
        image.src = img;
        var deferred = $.Deferred();
        if (img) {
            image.onload = function () {
                deferred.resolve(getBase64Image(image));//将base64传给done上传处理
            }
            return deferred.promise();//问题要让onload完成后再return sessionStorage['imgTest']
        }
    }
</script>