C#读写SQLSERVER中Image类型图片

 /// <summary>
        ///  向SQLSERVER数据库中写入图片
        /// </summary>
        /// <param name="fileStream">文件流</param>
        /// <returns></returns>
        public int WriteImage(FileStream fileStream)
        {
            try
            {
                var buffer = new byte[fileStream.Length];
                fileStream.Read(buffer, 0, (int)fileStream.Length);
                fileStream.Close();
                string strSql = "INSERT INTO DemoTab VALUES(@imageData)";
                SqlCommand cmd = new SqlCommand(strSql,sqlConn);
                cmd.Parameters.Add("@imageData", SqlDbType.Image).Value = buffer;
                return cmd.ExecuteNonQuery();

            }
            catch (Exception ex)
            {
                Log.WriteLog(ex.Message);
                return -1;
            }
            finally
            {
                CloseConn();
            }
        }
        
        /// <summary>
        /// 读取SQLSERVER表中Image类型的数据
        /// </summary>
        /// <returns></returns>
        public Bitmap ReadImage()
        {
            try
            {
                string strSql = "SELECT TOP 1 ImageData FROM DemoTab";
                SqlCommand sqlCmd = new SqlCommand(strSql,sqlConn);
                var byteImg = (byte[]) sqlCmd.ExecuteScalar();
                MemoryStream memoryStream = new MemoryStream(byteImg);
                Bitmap bitmap = new Bitmap(memoryStream);
                return bitmap;
            }
            catch (Exception ex)
            {
                Log.WriteLog(ex.Message);
                return null;
            }
            finally
            {
                CloseConn();
            }
        }