::For nothing can seem foul to those that win::

      在GridView里的模板页里设置如下：

  <asp:TemplateField HeaderText="排序">
            <ItemTemplate>
                <asp:TextBox ID="TextBox4"  onkeypress="InputNum()"  runat="server" Text='<%# bind("px") %>'
                    Width="25px"></asp:TextBox>
                <asp:Button ID="btn_up" runat="server" CssClass="ButtomBG45" Text="上移"
                    CausesValidation="False" CommandArgument="<%# Container.DataItemIndex  %>" CommandName="value_up"
                     />
                <asp:Button ID="btn_down" runat="server" CssClass="ButtomBG45" Text="下移"
                    CausesValidation="False" CommandArgument="<%# Container.DataItemIndex  %>" CommandName="value_down"
                   />
            </ItemTemplate>
        </asp:TemplateField>

    红色部分就是在保存当前的行号，知道了行号，就可以通过FindControl来找到控件，再找到值：

TextBox tb_value = (TextBox)GV_payMethod.Rows[int.Parse(e.CommandArgument.ToString())].Cells[1].FindControl("TextBox3");