C#读取数据库字节流生成图片

前台用DataList绑定

   <asp:DataList ID="DataList1" runat="server">
                <ItemTemplate>
                    <asp:Label ID="lbNwes" runat="server" Text='<%#Eval("Id")%>'></asp:Label>
                    &nbsp;
            <a href="<%# "ImageHandler.ashx?ImID="+ Eval("mainid") %>" target="_blank" title="点击放大看">
                <asp:Image ID="Image1" Width="100px" Height="100px" runat="server" ImageUrl='<%# "ImageHandler.ashx?ImID="+ Eval("mainid") %>' />

            </a>
                    <asp:Image ID="Image2" runat="server" Width="100px" Height="100px" />
                </ItemTemplate>
            </asp:DataList>

后台用ImageHandler.ashx处理程序处理数据,代码如下：

 public void ProcessRequest(HttpContext context)
        {
            context.Response.ContentType = "image/gif";
            string imageid = context.Request.QueryString["ImID"];
            byte[] MyData = new byte[0];
            using (SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["strconn"].ConnectionString))
            {
                conn.Open();
                SqlCommand cmd = new SqlCommand();
                cmd.Connection = conn;
                cmd.CommandText = "select Data from Blobs where mainid=" + imageid;
                SqlDataReader sdr = cmd.ExecuteReader();
                sdr.Read();
                MyData = (byte[])sdr["Data"];
                context.Response.BinaryWrite(MyData);
                
            }
        }

这样能实现图片绑定到DataList上，但有一个问题，当有100个图片时，必须发出100个请求。载图如下，希望有好的方法分享一下。