在<form>标签中加入  enctype="multipart/form-data"属性
//上传图片
  Stream   imageStream=File1.PostedFile.InputStream;
  string   imageType=File1.PostedFile.ContentType;
  int   imageSize=File1.PostedFile.ContentLength;
   byte[] imageContent=new byte[imageSize];
            int intstate=imageStream.Read(imageContent,0,imageSize);
  
 //使用sqlhelper类
            SqlParameter[] arameters=new SqlParameter[2];
   arameters[0]=new SqlParameter("@imageType",SqlDbType.VarChar,100);
   arameters[0].Value=imageType;
   arameters[1]=new SqlParameter("@imageContent",SqlDbType.Image);
   arameters[1].Value=imageContent;
   SqlHelper.ExecuteNonQuery(con,CommandType.Text,"insert into img values(@imageContent,@imageType)",arameters);

            //显示图片
   SqlDataReader dr=SqlHelper.ExecuteReader(con,CommandType.Text,"select * from img");
   while(dr.Read())
   {
    Response.ContentType=dr["imgtype"].ToString();
    Response.BinaryWrite((byte[])dr["img"]);
    
     }