layui实现登录加载loading的解决方案

 var $ = layui.jquery, upload = layui.upload;
        var loadingIndex;
        upload.render({
            elem: '#uploadImg'
            , url: '?m=News&a=newsDeal&act=upImg&fromImg=0'
            , multiple: true
            , accept: 'file' //普通文件
            , number: 1//上传个数
            , acceptMime: 'image/*'
            , exts: 'jpg|png|bmp|jpeg' //只允许上传压缩文件
            , before: function () {
                loadingIndex = layer.load();
            }
            , done: function (res) {
                layer.close(loadingIndex);
                if (res.status == "0") {
                    $("#news_img").val(res.imgUrl);
                }
            }
        });