Displaying uploaded files in Nested Gridview EditItemTemplate after Edit button Click

Hi,

I have uploaded some files inside a nested "GridView2_GK" of parent GridView1. But after "Edit" button click of GridView2_GK, the uploaded files (from folder) are disappearing in the cell. How to display thoses files in GridView2_GK EditItemTemplate? Also on Cancel Edit, the files are no longer displayed. Here is the code snippet:

		<asp:TemplateField HeaderText="TEST">
                         <HeaderTemplate>
                              <asp:Label ID="LabelGrunnkurs" runat="server" Text="TEST" />
                         </HeaderTemplate> 
		<ItemTemplate>

                <asp:ImageButton 
                    ID              ="imgShow_GK"
                    runat           ="server" 
                    OnClick         ="Show_Hide_ChildGrid_GK"
                    ImageUrl        ="~/images/plus.png" 
                    CommandArgument ="Show_GK" />

                <asp:Panel ID="pnlNested_GK" runat="server" Visible="false" Style="position:relative">

                                <asp:GridView ID="GridView2_GK" runat="server" 
                                    DataKeyNames    =   "GKID"
                                    OnRowEditing    =   "GridView2_GK_OnRowEditing"
                                    OnRowCancelingEdit  =   "GridView2_GK_OnRowCancelingEdit"
                                    ShowFooter          =   "True" >

                                    <Columns>
<%----------------------------------------------------------------------%>
                                        <asp:TemplateField HeaderText="MainID">
                                            <ItemTemplate>
                                                <asp:Label ID="lblMainID" Text='<%# Eval("MainID") %>' runat="server"></asp:Label>
                                            </ItemTemplate>
                                        </asp:TemplateField>
<%------------------------------------------------------------------------%>
                                        <asp:TemplateField HeaderText="GKID">
                                            <ItemTemplate>
                                                <asp:Label ID="lblGKID" Text='<%# Eval("GKID") %>' runat="server"></asp:Label>
                                            </ItemTemplate>
                                        </asp:TemplateField>
<%-------------------------------------------------------------------------%>
                                        <asp:TemplateField HeaderText="GKDocName">  
                                            <ItemTemplate>  
                                                <asp:HyperLink ID="LblGKDocName" runat="server" Target="_blank" NavigateUrl='<%# "Upload/GKFolder/" + Eval("GKDocName") %>'></asp:HyperLink>  
                                            </ItemTemplate>  

                                            <EditItemTemplate>
                                                <asp:HyperLink ID="LabelGKDocName" runat="server" Target="_blank" NavigateUrl='<%# "Upload/GKFolder/" + Eval("GKDocName") %>'></asp:HyperLink>    
                                                <asp:FileUpload ID="FileUploadGKDoc" runat="server" /> 
                                            </EditItemTemplate>

                                            <FooterTemplate>
                                                <asp:FileUpload ID="FileUploadGc" runat="server"/> 
                                            </FooterTemplate>

                                        </asp:TemplateField>    
<%-----------------------------------------------------------------------------%>

                                    <asp:TemplateField HeaderText="Add">
                                        <FooterTemplate>
                                            <asp:LinkButton ID="LinkBtnAddGK" runat="server" Text="Add" CommandName="InsertChild" />
                                        </FooterTemplate>
                                    </asp:TemplateField>
<%------------------------------------------------------------------------------%>
                    <asp:TemplateField HeaderText="Edit"> 

                        <ItemTemplate>
                            <asp:ImageButton ID="imgEditGK" runat="server" CommandName="Edit" ImageUrl="~/images/edit.svg" />
                        </ItemTemplate>

                        <EditItemTemplate>
                            <asp:ImageButton ID="imgUpdateGK" runat="server" CommandName="Update" ImageUrl="~/images/save.svg"  />
                            <asp:ImageButton ID="imgCancelGK" runat="server" CommandName="Cancel"  ImageUrl="~/images/cancel.svg" />
                        </EditItemTemplate>

                    </asp:TemplateField>

<%-------------------------------------------------------------------------------%>
                                    </Columns>
                                </asp:GridView>

                </asp:Panel>

						</ItemTemplate>
					</asp:TemplateField>

protected void GridView2_GK_OnRowEditing(object sender, GridViewEditEventArgs e) { GridView GridView2 = sender as GridView; GridViewRow row = GridView2.Rows[e.NewEditIndex]; // Get the row being edited

int mainid= Convert.ToInt32((row.Cells[0].FindControl("lblMainID") as Label).Text);

foreach (GridViewRow nestedRow in GridView2.Rows) { HyperLink LabelGKDocName = (nestedRow.Cells[3].FindControl("LabelGKDocName") as HyperLink);

LabelGKDocName.Text = GetDocuments_GK(); // This is always null

}

GridView2.EditIndex = e.NewEditIndex; BindOrders_GK(GridView2.ToolTip, GridView2); }

How to get and display the files in EditItemTemplate after Edit button click (GridView2_GK_OnRowEditing)? Also on GridView2_GK_OnRowCancelingEdit