向数据库存图片，并显示出来

/********************************
**向数据库插入图片
********************************/
 string ImgPath = FileUpload1.PostedFile.FileName;
            string ImgName = ImgPath.Substring(ImgPath.LastIndexOf("\\") + 1);
            string ImgExtend = ImgPath.Substring(ImgPath.LastIndexOf(".") + 1);
            if (!(ImgExtend == "bmp" || ImgExtend == "jpg" || ImgExtend == "gif"))
            {                
                Response.Write("<script>alert(\"对不起，图片错误！\")</script>");
            }
            int FileLen = this.FileUpload1.PostedFile.ContentLength;
            Byte[] FileData = new Byte[FileLen];
            HttpPostedFile hp = FileUpload1.PostedFile;//创建访问客户端上传文件的对象 
            Stream sr = hp.InputStream;//创建数据流对象 
            sr.Read(FileData, 0, FileLen);//将图片数据放到FileData数组对象实例中,其中0代表数组指针的起始位置,FileLen表示要读取流的长度(指针的结素位置)

            bll.addimage(id,FileData);//向数据库添加



/**************************************
*在另一个页面显示
**************************************/ 
if (!IsPostBack && Request.QueryString["id"] != null)
            {
                string str = Request.QueryString["id"];
                Byte[] b;
                if (Request.QueryString["id"] != null)
                {
                    SqlDataReader read = bll.getimage(Request.QueryString["id"]);
                    while (read.Read())
                    {
                        if (read["personimage"] != DBNull.Value)
                        {
                            b = (byte[])read["personimage"];
                            Response.ContentType = "image/Jpeg";//设定输出文件类型 
                            Response.BinaryWrite(b);                            
                        }                       
                    }
                    read.Close();
                }
                else
                {
                    Response.ContentType = "image/Jpeg";
                    Response.Write("noperson.gif");
                }
            }