private bool CheckFolderWriteable(string path)
        {
            if (!Directory.Exists(path))
            {
                Directory.CreateDirectory(Server.MapPath(path));
                return true;
            }

            try
            {
                string testFilePath = string.Format("{0}/test{1}{2}{3}{4}.txt", path, DateTime.Now.Hour, DateTime.Now.Minute, DateTime.Now.Second, DateTime.Now.Millisecond);
                FileStream TestFile = System.IO.File.Create(testFilePath); // 可读
                TestFile.WriteByte(Convert.ToByte(true)); // 可写
                TestFile.Close();
                System.IO.File.Delete(testFilePath);
                return true;
            }
            catch
            {
                return false;
            }

        }

如何检测文件夹是否可写可读