How to manage two elements of xml file

<Grid Background="{StaticResource ApplicationPageBackgroundThemeBrush}">
        <GridView SelectionChanged="gv1_selection_changed" Name="gv1" HorizontalAlignment="Left" Margin="66,51,0,0" VerticalAlignment="Top" Width="1241" Height="643" >
            <GridView.ItemTemplate>
                <DataTemplate>
                    <StackPanel Orientation="Vertical">
                        <Grid>
                            <Rectangle Fill="Blue" Tapped="Rectangle_Tapped"></Rectangle>
                            <TextBlock  FontSize="25" Width="200" Height="200" Text="{Binding name}"></TextBlock>
                            
                        </Grid>
                    </StackPanel>
                </DataTemplate>
            </GridView.ItemTemplate>
            

        </GridView>
        <PopUp Name="pop" isOpen="False">
              <TextBlock Name="tblock"/>
        </PopUp>
    </Grid>

protected async override void OnNavigatedTo(NavigationEventArgs e)
        {
            Windows.Storage.StorageFolder storagefolder = await
           Windows.ApplicationModel.Package.Current.InstalledLocation.GetFolderAsync("Common");
            Windows.Storage.StorageFile storagefile = await storagefolder.GetFileAsync("XMLFile1.xml");
            var stream = await storagefile.OpenAsync(Windows.Storage.FileAccessMode.Read);
            XmlDocument doc = await XmlDocument.LoadFromFileAsync(storagefile);
            XDocument xdoc = XDocument.Parse(doc.GetXml());
            var item = from n in xdoc.Descendants("item")
          
                       select new 
                       {
                           word= n.Element("name").Value,
                           meaning=n.Element("fathername").Value
                           
                       };
           
            gv1.ItemsSource = item;
          
        }
gv1_selection_changed(Object Sender,TappedRoutedEventArgs e))
{
int i=gv1.SelectedIndex();
pop.isOpen=true;
tblock.text=n[i].fathername;
}

I want to display a pop up which displays the father name when we select a name. So tried the above code but its not working.So how can i do it?