VerticalScrollBarVisibility of ListBox not working

<Style x:Key="ListBoxStyling3" TargetType="{x:Type ListBox}">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type ListBox}">
       <!--Set the VerticalScrollBarVisibility, When the vertical distance decreases, but the VerticalBar did not come out-->
                <ScrollViewer HorizontalScrollBarVisibility="Disabled" VerticalScrollBarVisibility="Auto">
                    <WrapPanel IsItemsHost="True"/>
                </ScrollViewer>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
    <Setter Property="ItemTemplate">
        <Setter.Value>
            <DataTemplate>
                <Grid>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="60"/>
                        <RowDefinition Height="30"/>
                    </Grid.RowDefinitions>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="140"/>
                    </Grid.ColumnDefinitions>
                    <Image Margin="2,2,2,1" Source="{Binding Path}" Width="48"/>
                    <TextBlock Grid.Row="1" Margin="5" HorizontalAlignment="Center" Text="{Binding Name}" FontWeight="Bold" FontSize="14"/>
                </Grid>
            </DataTemplate>
        </Setter.Value>
    </Setter>