WPF ListboxItems Cosume too much memory

Question

Ok i have an WPF application in wich i create my own ListBoxItem in a resource dictionary that looks like this :

    <DataTemplate x:Key="StationItem">
    <Grid x:Name="Gridder" Tag="{Binding SItem.StationName}" Width="125" Height="55">
        <Grid.RowDefinitions>
            <RowDefinition Height="*"/>
            <RowDefinition Height="20"/>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="20"/>
        </Grid.ColumnDefinitions>
        <Rectangle x:Name="Rectagler" Width="120" Height="50" RadiusX="5" RadiusY="5" VerticalAlignment="Center" HorizontalAlignment="Center" Grid.ColumnSpan="2" Grid.RowSpan="2" StrokeThickness="1" Stroke="Black">
            <Rectangle.Fill>
                <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                    <GradientStop Color="#FFFF3A00" Offset="0"/>
                    <GradientStop Color="#FFE88D20" Offset="1"/>
                </LinearGradientBrush>
            </Rectangle.Fill>
        </Rectangle>
        <TextBlock Grid.Column="0" Grid.Row="0" Grid.ColumnSpan="2" x:Name="StationName" Text="{Binding SItem.StationName}" Foreground="Black" FontSize="14" FontWeight="SemiBold" TextWrapping="NoWrap" VerticalAlignment="Center" HorizontalAlignment="Left" Margin="10,0,0,0"/>
        <TextBlock Grid.Column="0" Grid.Row="1" x:Name="StationCountry" Text="{Binding SItem.StationCountry}" Foreground="WhiteSmoke" FontSize="11" FontWeight="Light" TextWrapping="NoWrap" VerticalAlignment="Center" HorizontalAlignment="Left" Margin="10,0,0,8"/>
        <Image Tag="{Binding SItem.StationName}" Width="15" Height="15" RenderOptions.BitmapScalingMode="HighQuality" Grid.Column="1" Grid.Row="1" Source="{Binding FavSource}" VerticalAlignment="Center" HorizontalAlignment="Center" Margin="0,0,10,10"/>
    </Grid>
    <DataTemplate.Triggers>
        <Trigger Property="IsMouseOver" Value="true">
            <Setter TargetName="Rectagler" Property="Width" Value="125"/>
            <Setter TargetName="Rectagler" Property="Height" Value="55"/>
            <Setter TargetName="StationName" Property="Foreground" Value="White"/>
        </Trigger>
    </DataTemplate.Triggers>
</DataTemplate>

A ListBox like this :

        <ListBox x:Name="StationsListLB" Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="5" ItemTemplate="{DynamicResource GenreStyle}" ItemContainerStyle="{DynamicResource ContainerStyle}" Background="{x:Null}" BorderBrush="{x:Null}" PreviewMouseLeftButtonDown="StationsListLB_PreviewMouseLeftButtonDown" ScrollViewer.HorizontalScrollBarVisibility="Auto" ScrollViewer.VerticalScrollBarVisibility="Disabled" PreviewMouseDoubleClick="StationsListLB_PreviewMouseDoubleClick">
        <ListBox.ItemsPanel>
            <ItemsPanelTemplate>
                <WrapPanel IsItemsHost="True" Orientation="Vertical" MaxHeight="220" ScrollViewer.HorizontalScrollBarVisibility="Disabled" ScrollViewer.VerticalScrollBarVisibility="Disabled" HorizontalAlignment="Center" VerticalAlignment="Center"/>
            </ItemsPanelTemplate>
        </ListBox.ItemsPanel>
    </ListBox>

And i populate my ListBox items when the user chooses an Genre of the station, with a method like this :

 public class Stations
{
    public StationItem SItem { get; set; }
    public string FavSource { get; set; }
}

public class StationItem
{
    public string StationName { get; set; }
    public string StationUrl { get; set; }
    public string StationGenre { get; set; }
    public string StationWebsite { get; set; }
    public string StationCountry { get; set; }
}

    private void LoadStationByGenre(string Genre)
    {
        StationsListLB.Items.Clear();
        StationsListLB.ItemTemplate = (DataTemplate)FindResource("StationItem");

        IEnumerable<Stations> results = StationList.Where(s => s.SItem.StationGenre.Equals(Genre));

        foreach (var Station in results)
        {
            StationsListLB.Items.Add(Station);
        }
    }

Note : Every StationGenre will populate my ListBox with at least 1000 StationItems.

My code works fine and starts with a memory of 40MB (Window Task Manager). But whenever i select a genre and populate my ListBox, memory explodes at 100MB.And i then select another genre memory explodes further. I thought that with ListBox.Items.Clear(); the ListBoxItems will be destroyed from memory too, but this doesnt happen.

I tried to remove the image from my ListoBoxItemTemplate and checked my app's memory, but didnt see a real difference (About 4-7 MB's difference).

So my answer is : How can i make my application consume a lot less memory when adding items in the ListBox?

Thanks in advance!!

Answer 1

Try use VirtualizingStackPanel.VirtualizationMode="Recycling" to improve performance. Quote from MSDN:

By default, a VirtualizingStackPanel creates an item container for each visible item and discards it when it is no longer needed (such as when the item is scrolled out of view). When an ItemsControl contains a lot of items, the process of creating and discarding item containers can negatively affect performance. When VirtualizingStackPanel.VirtualizationMode is set to Recycling, the VirtualizingStackPanel reuses item containers instead of creating a new one each time.