如何使用内存stream读取excel文件数据？

我想从我从ARC发送的JSON数据读取Excel文件，任何人都可以帮我解决吗？

public bool ControlAttachment(AttachmentFile file) { try { if (file != null && file.File != null) { string xlsfile = file.File; string [] xls = {"application/excel","application/vnd.msexcel","xls","xlsx","application/vnd.ms-excel",}; if (xls.ToList().Contains(file.FileType.Trim())) { file.FileType = ".xls"; byte[] contents = Convert.FromBase64String(xlsfile); string LogFilePaths = ConfigurationManager.AppSettings["ExcelMapperPath"]; string fileName = file.FileName.Split('.')[0] + file.FileType; string LogFile = HttpContext.Current.Server.MapPath(LogFilePaths + file.FileName.Split('.')[0] + file.FileType); System.IO.File.WriteAllBytes(LogFile, contents); if (!File.Exists(LogFile)) { File.Create(LogFile).Dispose(); } MemoryStream ms = new MemoryStream(); using (var fs = new FileStream(LogFile, FileMode.Open, FileAccess.Write)) { ms.CopyTo(fs); ms.Dispose(); } } } return true; } catch { return false; } }