上传图片到数据库和从数据库下载下来

private void UploadFile()
           
        {
            /**//**//**////得到用户要上传的文件名
            string strFilePathName = loFile.PostedFile.FileName;
            string strFileName = Path.GetFileName(strFilePathName);
            int FileLength = loFile.PostedFile.ContentLength;
               
            if(FileLength<=0)
                return;
       
            /**//**//**////上传文件
            //                    try
            //                    
            //                    {            
            /**//**//**////图象文件临时储存Byte数组
            Byte[] FileByteArray = new Byte[FileLength];
                    
            /**//**//**////建立数据流对像
            Stream StreamObject = loFile.PostedFile.InputStream; 
                    
            /**//**//**////读取图象文件数据，FileByteArray为数据储存体，0为数据指针位置、FileLnegth为数据长度
            StreamObject.Read(FileByteArray,0,FileLength); 
                   
            /**//**//**////建立SQL Server链接
            //                    string strCon = System.Configuration.ConfigurationSettings.AppSettings["DSN"];
            SqlConnection Con = new SqlConnection("server=.;uid=sa;pwd=sa;database=wjoa");
            String SqlCmd = "INSERT INTO ImageStore (ImageData, ImageContentType, ImageDescription, ImageSize) VALUES (@Image, @ContentType, @ImageDescription, @ImageSize)";
            SqlCommand CmdObj = new SqlCommand(SqlCmd, Con);
            CmdObj.Parameters.Add("@Image",SqlDbType.Image, FileLength).Value = FileByteArray;
            CmdObj.Parameters.Add("@ContentType", SqlDbType.VarChar,2000).Value = loFile.PostedFile.ContentType; //记录文件类型
                     
            /**//**//**////把其它单表数据记录上传
            CmdObj.Parameters.Add("@ImageDescription", SqlDbType.VarChar,2000).Value = tbDescription.Text;
                           
            /**//**//**////记录文件长度，读取时使用
            CmdObj.Parameters.Add("@ImageSize", SqlDbType.Int).Value = FileLength;
            Con.Open();
            CmdObj.ExecuteNonQuery(); 
            Con.Close();
                    
            /**//**//**////跳转页面
            //                        Response.Redirect("ShowAll.aspx");
            //                    }
            //               
            //                    catch(Exception ex)
            //                
            //                        {
            //                                throw ex;
            //                        }
        }

        private void ShowImages()
            
        {
            /**//**//**////ID为图片ID
            int ImgID = int.Parse(this.TextBox1.Text.Trim());  
            
            /**//**//**////建立数据库连接
           
            SqlConnection Con = new SqlConnection("server=.;uid=sa;pwd=sa;database=wjoa");
            String SqlCmd = "SELECT * FROM ImageStore WHERE id = @ImageID";
            SqlCommand CmdObj = new SqlCommand(SqlCmd, Con);
            CmdObj.Parameters.Add("@ImageID", SqlDbType.Int).Value = ImgID;
           
            Con.Open();
            SqlDataReader SqlReader = CmdObj.ExecuteReader();
            SqlReader.Read(); 
       
            /**//**//**////设定输出文件类型
            Response.ContentType = (string)SqlReader["ImageContentType"];
           
            /**//**//**////输出图象文件二进制数制
            Response.OutputStream.Write((byte[])SqlReader["ImageData"], 0, (int)SqlReader["ImageSize"]); 
            Response.End();
       
            Con.Close();    
        }