grid view 的翻页功能不能实现

Question

  前台 
     <asp:GridView ID="GridView1" runat="server" AllowPaging="True" AutoGenerateColumns="False"
                                    BorderStyle="None" BorderWidth="0px" DataKeyNames="ID" Font-Size="12px" ForeColor="Black"
                                    Width="97%" OnPageIndexChanging="GridView1_PageIndexChanging">
                                    <PagerStyle Font-Size="15px" HorizontalAlign="Center" />
                                    <PagerSettings FirstPageText="第一页" LastPageText="最后一页" Mode="NumericFirstLast" NextPageText="下一页"
                                        PreviousPageText="上一页" />
                                    <Columns>
                                        <asp:TemplateField HeaderText="Equick Number">
                                            <ItemTemplate>
                                                &nbsp;<asp:Label ID="Label4" runat="server" Height="26px" Text='<%# Bind("order_ID") %>'
                                                    Width="80px"></asp:Label>
                                            </ItemTemplate>
                                            <HeaderStyle BackColor="Gainsboro" ForeColor="Black" />
                                            <ItemStyle Font-Names="Arial" />
                                        </asp:TemplateField>
                                        <asp:TemplateField HeaderText="地点/签收人" SortExpression="track_Place">
                                            <EditItemTemplate>
                                                <asp:TextBox ID="TextBox2" runat="server" Text='<%# Bind("track_signedby") %>'></asp:TextBox>
                                            </EditItemTemplate>
                                            <ItemTemplate>
                                                <asp:Label ID="Label2" runat="server" Text='<%# Bind("track_signedby") %>'></asp:Label>
                                            </ItemTemplate>
                                            <HeaderStyle BackColor="Gainsboro" />
                                            <ItemStyle Font-Names="Arial" />
                                        </asp:TemplateField>
                                        <asp:TemplateField HeaderText="货物状态" SortExpression="track_Status">
                                            <EditItemTemplate>
                                                <asp:TextBox ID="TextBox3" runat="server" Text='<%# Bind("ftrack_Status") %>'></asp:TextBox>
                                            </EditItemTemplate>
                                            <ItemTemplate>
                                                <asp:Label ID="Label3" runat="server" Text='<%# Bind("ftrack_Status") %>'></asp:Label>&nbsp;
                                            </ItemTemplate>
                                            <HeaderStyle BackColor="Gainsboro" />
                                            <ItemStyle Font-Names="Arial" />
                                        </asp:TemplateField>
                                        <asp:TemplateField HeaderText="目的地国家">
                                            <ItemTemplate>
                                                <asp:Label ID="Labeln" runat="server" Height="26px" Text='<%# Bind("country") %>'
                                                    Width="80px"></asp:Label>
                                            </ItemTemplate>
                                            <HeaderStyle BackColor="Gainsboro" />
                                            <ItemStyle Font-Names="Arial" />
                                        </asp:TemplateField>
                                        
                                      <asp:TemplateField HeaderText="发件日期">
                                            <ItemTemplate>
                                                <asp:Label ID="Labeln1" runat="server" Height="26px"   Text='<%# Bind("track_time") %>'
                                                    Width="80px"></asp:Label>
                                            </ItemTemplate>
                                            <HeaderStyle BackColor="Gainsboro" />
                                            <ItemStyle Font-Names="Arial" />
                                        </asp:TemplateField>
                                        
                                        
                                        
                                        <asp:TemplateField HeaderText="查看详情">
                                            <ItemTemplate>
                                                <asp:ImageButton ID="ImageButton1" runat="server" ImageUrl="~/imgs/1_03.jpg" OnClick="ImageButton1_Click" /><br />
                                            </ItemTemplate>
                                            <HeaderStyle BackColor="Gainsboro" HorizontalAlign="Left" />
                                            <ItemStyle HorizontalAlign="Left" Font-Names="Arial" />
                                        </asp:TemplateField>
                                    </Columns>
                                     <PagerStyle Font-Overline="False" Font-Underline="False" ForeColor="#6F6F6F" CssClass="DGPage" />
                                    <RowStyle Font-Names="Arial" />
                                    <AlternatingRowStyle BackColor="White" />
                                    
                                </asp:GridView>
  后台   private void bind()
    {
        string ordersid = "";
        string[] arry;
        StringBuilder orders = new StringBuilder();
        string fuhao = "','";
        string end = "'";
        SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["WLConnectionString3"].ConnectionString);
        
        DataSet ds = new DataSet();
        Regex rg = new Regex(@",");
              if (Session["ordersid"] != null)
        {
            ordersid = Session["ordersid"].ToString();
            arry = rg.Split(ordersid);
            Session["ordersid"] = null;
          for (int i = 0; i < arry.Length; i++)
                {
                    orders.Append(arry[i].Trim().ToString());
                    orders.Append(fuhao);
                }
                orders.Append(end);
                string sql="";
               
                Response.Write("arr"+arry.Length.ToString());
            
                  
             
            
            sql = string.Format("SELECT * FROM Order_Track  WHERE order_ID IN('{0}) AND Track_time = any (SELECT MAX(track_time) FROM Order_Track WHERE order_id IN ('{1}) GROUP BY Order_ID)", orders, orders);
         
                SqlConnection strcon = new SqlConnection(System.Configuration.ConfigurationManager.AppSettings["strcon"]);
                strcon.Open();
                             SqlCommand com3 = new SqlCommand(sql, strcon);
                int a = com3.ExecuteNonQuery();
                if (a <1)
                {
                    this.Label6.Text = "无查询结果";
                }                strcon.Close();
*/
            //}        }
           }
    protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
    {
        this.GridView1.PageIndex = e.NewPageIndex;
        this.bind();
    }   比如说数据有两页 ，那么第一次加载时显示第一页的，可以翻到第2页 ，但是在第2页时 ，就不能再接着翻到第一页了 ，好像是只能从前往后翻 ，不能从后往前翻 ，怎么回事啊 
    

Answer 1

protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e) 
    { 
        this.GridView1.PageIndex = e.NewPageIndex;         this.GridView1.DataSource = dt; //重新绑定你的数据源        this.GridView1.bind(); 
    }  

Answer 2

   this.GridView1.DataSource = dt; //重新绑定你的数据源        this.GridView1.bind();  这两句代码已经包含在在这个  private void bind()  这个函数里了     this.bind();