GridView dynamic column width in WPF

<Window x:Class="GridViewSample.Window1"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"Title="Window1"><Grid><Grid.RowDefinitions><RowDefinition/><RowDefinition/></Grid.RowDefinitions><ListView Name="CheckoutList" Margin="0,0,8,0"><ListView.View><GridView x:Name="CheckOutGridView"><GridView.ColumnHeaderContainerStyle><Style TargetType="{x:Type GridViewColumnHeader}"><Setter Property="Visibility" Value="Collapsed"/></Style></GridView.ColumnHeaderContainerStyle><GridViewColumn><GridViewColumn.CellTemplate><DataTemplate><TextBlock> <Hyperlink >          <TextBlock Text="{Binding Path=Text}"/> </Hyperlink> </TextBlock></DataTemplate></GridViewColumn.CellTemplate></GridViewColumn><GridViewColumn><GridViewColumn.CellTemplate><DataTemplate><TextBlock> <Hyperlink>          <TextBlock Text="Remove"/> </Hyperlink> </TextBlock></DataTemplate></GridViewColumn.CellTemplate></GridViewColumn></GridView></ListView.View></ListView><StackPanel Grid.Row="1"><Button Width="100" Height="25" Click="Button_Click">name</Button><Button Width="100" Height="25" Click="Button_Click1">long name</Button></StackPanel></Grid>

public partial class Window1 : Window{    class TextObject    {        private string _text;        public TextObject(string Text)        {            _text = Text;        }        public string Text        {            get { return _text; }            set { _text = value; }        }    }    public Window1()    {        InitializeComponent();    }    private void Button_Click(object sender, RoutedEventArgs e)    {        CheckoutList.Items.Add(new TextObject("name"));    }    private void Button_Click1(object sender, RoutedEventArgs e)    {        CheckoutList.Items.Add(new TextObject("long name"));    }}

Given the above sample press name then long name. How come the column doesn't resize to fit its contents?