图片image和byte处理,fileupload上传图片

--
这是通过浏览某图片，把他存放到数据库中

string  filename  =  txt_filename.Text;
         string  filecomment  =  txt_filecomment.Text;
         string  SlaveFileName  =  FileUpload1.PostedFile.FileName;
         byte [] FileContent_img  =   null ;
        DateTime UploadTime  =  DateTime.Now.Date;

         string  id  =  lbl_id.Text;
        RemoteRule remoteRule  =  (RemoteRule)GetRemoteingObjectByType( typeof (RemoteRule),  " remoterule " );
        DataSet ds  =   new  DataSet();
         if  (id  ==   "" )
         {
            ds = remoteRule.GetRuleByID(-1);
            DataRow dr = ds.Tables[0].NewRow();
            if (SlaveFileName != "")
            {
                //读取所上传的文件的二进制流
                HttpPostedFile file1 = FileUpload1.PostedFile;
                int filelength = Convert.ToInt32(file1.InputStream.Length);
                FileContent_img = new byte[filelength];
                file1.InputStream.Read(FileContent_img, 0, filelength);//这里所说的二进制流表现为什么样
            }
            else
            {
                SlaveFileName = null;
            }

            dr["FileName_ch"] = filename;
            dr["FileDesc_ch"] = filecomment;
            dr["SlaveFileName_ch"] = SlaveFileName;
            dr["FileContent_img"] = FileContent_img;
            dr["UploadUser_ch"] = this.SystemModuleSettings.UserManage.CurrUserInfo["RealName"].ToString();
            dr["UploadTime_dt"] = UploadTime;
            ds.Tables[0].Rows.Add(dr);
            string result = remoteRule.InsRule(ds);
            if (result == "")
            {
                Response.Write(" ");
            }
            else
            {
                if (result != "f")
                {
                    Response.Write(" ");
                    ViewState["PageState"] = "edit";
                    lbl_id.Text = result.Substring(result.IndexOf(",") + 1);
                    setControlsValue();
                }
                else
                {
                    Response.Write(" ");
                }
            }
        }  

--
显示图片的

byte [] Image_img  =  ( byte [])ds_image.Tables[ 0 ].Rows[ 0 ][ " Image_im " ];
                             if  (Image_img.Length  ==   0 )
                                 return ;
                             int  filelength  =  Image_img.Length;
                             string  imageName  =  ds_image.Tables[ 0 ].Rows[ 0 ][ 1 ].ToString()  +   " 1 "   +   " .jpg " ;
                             string  myUrl  =  HttpContext.Current.Server.MapPath( this .Request.ApplicationPath)  +   @" \TempDownLoad\ "   +  imageName;
                            FileStream fs  =   new  FileStream(myUrl, FileMode.OpenOrCreate);
                            BinaryWriter w  =   new  BinaryWriter(fs);
                            w.BaseStream.Write(Image_img,  0 , filelength);
                            w.Flush();
                            w.Close();

                            Image1.ImageUrl  =  Context.Request.ApplicationPath  +   " /TempDownLoad/ "   +  imageName;
                            Bitmap bitmap  =   new  Bitmap(myUrl);
                            Image1.Width  =  bitmap.Width;
                            Image1.Height  =  bitmap.Height;