var fileName = $("#sectionfileUpload").val(); //C:\fakepath\3.jpeg

            var exts = fileName.split('.');

            var ext = "";

            if (exts != undefined) {

                if (exts.length <= 1 && fileName.indexOf('=')>-1) {//直接输入上传到azure之后生成的文件地址

                    console.log(exts.length);

                } else {

                    ext = exts[exts.length - 1];

                    ext = ext.toLowerCase();

                    if (ext != 'ppt' && ext != 'pptx' && ext != 'doc' && ext != 'docx' && ext != 'xls'

                        && ext != 'xlsx' && ext != 'pdf' && ext != 'mp4') {

                        toaster.pop('error', "上传失败，文件格式限制为office文件、pdf、mp4视频文件");

                        return;

                    }

                }

            }

            //获取视频或者音频时长

            var fileurl = URL.createObjectURL(file);

            //经测试，发现audio也可获取视频的时长

            var audioElement = new Audio(fileurl);

            var duration;

            audioElement.addEventListener("loadedmetadata", function (_event) {

                duration = audioElement.duration;

                console.log( "duration");

                console.log(duration);//单位：秒

            });

            //获取文件大小

            var size = file.size;//单位：字节(byte)