Retrieve selected row info from ListView

I am trying to retrieve the selected row info (eg. each cell) from the listview.

The Listview is set-up like this:

        public MainWindow()
        {
            InitializeComponent();

            var view = new GridView();
            view.Columns.Add(new GridViewColumn { Header = "First Name", DisplayMemberBinding = new Binding("First") });
            view.Columns.Add(new GridViewColumn { Header = "Last Name", DisplayMemberBinding = new Binding("Last") });
            view.Columns.Add(new GridViewColumn { Header = "Your Age", DisplayMemberBinding = new Binding("Age") });
            codeListView.View = view;
            codeListView.Items.Add(new { First = "Bill", Last = "Smith", Age = 91 });
            codeListView.Items.Add(new { First = "Jane", Last = "Doe", Age = 33 });

        }

Then I try to retrieve the selected info from the row... 

        private void codeListView_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            textBox1.Text = codeListView.SelectedItems[0].ToString();

        }

The info comes out like this:  { First = Jane, Last = Doe, Age = 33 }

How can I retrieve just "Jane" or just "33"?