public bool Upload(HttpPostedFileBase file)
{
MemoryStream target = new MemoryStream();
file.InputStream.CopyTo(target);
byte[] data = target.ToArray();
HttpFile httpFile = new HttpFile(file.FileName, file.ContentType, data);
DataSet dataSet = ReadExcel.ToDataSet(httpFile.Buffer);
DataTable resultDt = dataSet.Tables[0];
List <Student> students = new List <Student>();
students = Convertor.ConvertToList <Student>(resultDt);
return(true);
}