System.Web.HttpException on asp:gridview pagination

Question

I have the following <asp:gridview> with one one TemplateField. En each cell there is an image with a link and a text with a link. It has AllowPaging=True

This is the gridview:

<asp:GridView ID="gvExperiencias" runat="server" AllowPaging="True" GridLines="None"
    ShowHeader="False" AutoGenerateColumns="False" Width="650px" PageSize="4"
    OnDataBinding="gvExperiencias_DataBinding"
    OnPageIndexChanging="gvExperiencias_PageIndexChanging">
        <PagerSettings Mode="NumericFirstLast"
            FirstPageImageUrl="~/images/fle_pag_izq.gif"
            LastPageImageUrl="~/images/fle_pag_der.gif"
            NextPageImageUrl="~/images/fle_pag_der.gif"
            PreviousPageImageUrl="~/images/fle_pag_izq.gif"
            Position="TopAndBottom" PageButtonCount="4" FirstPageText=""
            LastPageText="" NextPageText="" PreviousPageText="" />
        <Columns>
            <asp:TemplateField>
                <ItemTemplate>
                    <div id="it_0" class="new_solo_exp_ini">
                        <asp:HyperLink ID="a_0" runat="server" Visible='<%# Eval("NotEmpty_0") %>'
                            NavigateUrl='<%# "experiencia.aspx?cod_cod=" + Eval("tttb_articulo_relacion_0.ARTCOD_ARTREL") + "&pag=" + pag + "&grp=" + Eval("idiocod_cod_idi_0") + "&cod="+cod %>'>
                            <asp:Image ID="Image_0" runat="server" Height="88px"
                                ImageUrl='<%# Eval("arigls_nom_img_0","~/ArchivosUsuario/1/1/Articulos/{0}") %>'
                                Width="88px" CssClass="new_image_exp_ini" />
                        </asp:HyperLink>
                        <div class="new_vineta_tit_exp_ini">
                            <asp:HyperLink ID="HyperLink_0" runat="server"
                                NavigateUrl='<%# "experiencia.aspx?cod_cod=" + Eval("tttb_articulo_relacion_0.ARTCOD_ARTREL") + "&pag=" + pag + "&grp=" + Eval("idiocod_cod_idi_0") + "&cod="+cod %>'
                                Text='<%# Bind("arigls_tit_0") %>'>
                            </asp:HyperLink>
                        </div>
                </div>
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
    <PagerStyle CssClass="new_pag_bajo_exp_ini" />
    <RowStyle CssClass="new_fila_exp_ini" />
</asp:GridView>

When I click the last button or the ... it goes to the corresponding page but when i click on a previous page i get the following error:

An Error Has Occurred Because A Control With Id $ContentPlaceHolder1$gvExperiencias$ctl01$ctl01' Could Not Be Located Or A Different Control Is assigned to the same ID after postback. If the ID is not assigned, explicitly set the ID property of controls that raise postback events to avoid this error.

So the pager does not work correctly. I think it's because of the Image's Id that has to be generated dynamically but i don't know how to do it.

Answer 1

I suspect the GridView is confused because not all of the elements in the template have runat="server" set to true. This messes up the NamingContainer heirarchy. Try setting runat="server" on your div elements:

<ItemTemplate>
<div id="it_0" class="new_solo_exp_ini" runat="server">
 <asp:HyperLink ID="a_0" runat="server" NavigateUrl='<%# "experiencia.aspx?cod_cod=" + Eval("tttb_articulo_relacion_0.ARTCOD_ARTREL") + "&pag=" + pag + "&grp=" + Eval("idiocod_cod_idi_0") + "&cod="+cod %>'
  Visible='<%# Eval("NotEmpty_0") %>'>
  <asp:Image ID="Image_0" runat="server" Height="88px" ImageUrl='<%# Eval("arigls_nom_img_0","~/ArchivosUsuario/1/1/Articulos/{0}") %>'
   Width="88px" CssClass="new_image_exp_ini" />
 </asp:HyperLink>
 <div id="some_id" class="new_vineta_tit_exp_ini" runat="server">
  <asp:HyperLink ID="HyperLink_0" runat="server" NavigateUrl='<%# "experiencia.aspx?cod_cod=" + Eval("tttb_articulo_relacion_0.ARTCOD_ARTREL") + "&pag=" + pag + "&grp=" + Eval("idiocod_cod_idi_0") + "&cod="+cod %>'
   Text='<%# Bind("arigls_tit_0") %>'>
  </asp:HyperLink>
 </div>
</div>

You'll also have to add an id to the second div, and the div ids will be modified by the NamingContainer, so if you reference them via JavaScript, you'll have to use their ClientID property to determine what their actual id is.