Accessing A TextBox From A ListView Item

I have a ListView with an ItemSource containg an collection of items from a custom class named "ListItem".

Here is the XAML related to my issue:

<ListView Name="listView1" ItemsSource="{Binding Path=listItemCollection}" DataContext="{Binding ListItem}"><ListView.View><GridView x:Name="gridViewMain"><GridViewColumn x:Name="listViewItemNumberColumn" Width="50"><GridViewColumnHeader>#</GridViewColumnHeader><GridViewColumn.CellTemplate><DataTemplate><TextBlock x:Name="idTextBlock" KeyboardNavigation.IsTabStop="False" HorizontalAlignment="Center" Text="{Binding Path=Id}"/></DataTemplate></GridViewColumn.CellTemplate></GridViewColumn><GridViewColumn x:Name="listViewItemNameColumn" Width="500"><GridViewColumnHeader>Name</GridViewColumnHeader><GridViewColumn.CellTemplate><DataTemplate><TextBox x:Name="nameTextBox" TextChanged="nameTextBox_TextChanged" Text="{Binding Path=ItemName, UpdateSourceTrigger=PropertyChanged}"/></DataTemplate></GridViewColumn.CellTemplate></GridViewColumn>
            ...

I want to be able to access the TextBox "nameTextBox" so that I can do things such as call the Focus() method on it. 

My listItemCollection is an ObservableCollection<ListItem>. And this what my ListItem class looks like:

public class ListItem : INotifyPropertyChanged {
    public event PropertyChangedEventHandler PropertyChanged;

    public bool Selected { get; set; }
    public string ItemName { get; set; }

The main problem is that when it comes to accessing an item of the ListView, it returns a ListItem, and I cannot access the any of the actual controls such as the TextBlock "idTextBlock", and neither the TextBox "nameTextBox".

How can I actually find and a specific (or even every) textbox such as "nameTextBox" in the ListView so that I can call methods such as Focus on them?

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