<ValueConversion(GetType(Object), GetType(String))> _
Public Class ValueConverter
    Implements IValueConverter
 
    Public Function Convert(ByVal value As Object, ByVal targetType As _
      System.Type, ByVal parameter As Object, ByVal culture As _
      System.Globalization.CultureInfo) As Object Implements _
      System.Windows.Data.IValueConverter.Convert
        Return CDbl(value).ToString("f2")
    End Function
 
    Public Function ConvertBack(ByVal value As Object, ByVal targetType As _
      System.Type, ByVal parameter As Object, ByVal culture As _
      System.Globalization.CultureInfo) As Object Implements _
      System.Windows.Data.IValueConverter.ConvertBack
        Throw New NotSupportedException("ConvertBack not supported")
    End Function
End Class

    <Window.Resources>
        <local:ValueConverter x:Key="ValueConv" />
        <Style x:Key="ItemStyle" TargetType="{x:Type ListViewItem}">
            <Style.Resources>
                <DataTemplate x:Key="ItemTemplate">
                    <TextBlock Margin="0,5,0,5" Text="{Binding Value," & _
                      "Converter={StaticResource ValueConv}}" />
                </DataTemplate>
            </Style.Resources>
 
            <Style.Triggers>
                <Trigger Property="IsMouseOver" Value="True" >
                    <Setter Property="ContentTemplate" Value="{StaticResource" _
                      & _
                      "ItemTemplate}" />
                </Trigger>
            </Style.Triggers>
        </Style>
    </Window.Resources>
    <Grid>
        <ListView Name="ListView1" ItemContainerStyle="{StaticResource" & _
          "ItemStyle}" ItemsSource="{Binding}" DisplayMemberPath="Name" _
          ></ListView>
    </Grid>