Setting ContentPresenter with MultiDataTrigger produces memory leak - wpf

Question

I have a ListBox which Item's ContentPresenter is changed by MultiDataTrigger depending on some IsTool and IsAlerting boolean properties:
<Grid>
<Grid.Resources>
<DataTemplate x:Key="LayerTemplate">
<ContentControl x:Name="contentControl" Style="{DynamicResource PageHeaderContentControlStyle}">
<layers:PageHeader/>
</ContentControl>
</DataTemplate>
<DataTemplate x:Key="ToolTemplate">
<ContentControl x:Name="contentControl" Style="{DynamicResource ToolHeaderContentControlStyle}">
<layers:ToolHeader/>
</ContentControl>
</DataTemplate>
<DataTemplate x:Key="LayerAlertTemplate">
<ContentControl x:Name="contentControl" Style="{DynamicResource PageHeaderAlertContentControlStyle}">
<layers:PageHeader/>
</ContentControl>
</DataTemplate>
<DataTemplate x:Key="ToolAlertTemplate">
<ContentControl x:Name="contentControl" Style="{DynamicResource ToolHeaderAlertContentControlStyle}">
<layers:ToolHeader/>
</ContentControl>
</DataTemplate>
<Style TargetType="{x:Type ListBoxItem}" x:Key="EmptyListViewSelection">
<Setter Property="Background" Value="Transparent" />
<Setter Property="FocusVisualStyle" Value="{x:Null}"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ListBoxItem}">
<Border BorderBrush="Transparent"
BorderThickness="0"
Background="{TemplateBinding Background}"
Margin="2"
FocusVisualStyle="{x:Null}">
<ContentPresenter DataContext="{Binding}" Name="contentPresenter"/>
</Border>
<ControlTemplate.Triggers>
<DataTrigger Binding="{Binding IsTool}" Value="False">
<Setter TargetName="contentPresenter" Property="ContentTemplate" Value="{StaticResource LayerTemplate}"/>
</DataTrigger>
<DataTrigger Binding="{Binding IsTool}" Value="True">
<Setter TargetName="contentPresenter" Property="ContentTemplate" Value="{StaticResource ToolTemplate}"/>
</DataTrigger>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding IsTool}" Value="False"/>
<Condition Binding="{Binding IsAlerting}" Value="True"/>
</MultiDataTrigger.Conditions>
<MultiDataTrigger.Setters>
<Setter TargetName="contentPresenter" Property="ContentTemplate" Value="{StaticResource LayerAlertTemplate}"/>
</MultiDataTrigger.Setters>
</MultiDataTrigger>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding IsTool}" Value="True"/>
<Condition Binding="{Binding IsAlerting}" Value="True"/>
</MultiDataTrigger.Conditions>
<MultiDataTrigger.Setters>
<Setter TargetName="contentPresenter" Property="ContentTemplate" Value="{StaticResource ToolAlertTemplate}"/>
</MultiDataTrigger.Setters>
</MultiDataTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Grid.Resources>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<ListBox Name="listView"
BorderThickness="0"
ItemsSource="{Binding Pages}"
SelectedValue="{Binding SelectedPage}"
ScrollViewer.HorizontalScrollBarVisibility="Hidden"
ScrollViewer.VerticalScrollBarVisibility="Hidden"
ItemContainerStyle="{StaticResource EmptyListViewSelection}"
IsTabStop="False"
FocusVisualStyle="{x:Null}"
Focusable="False" Background="{x:Null}">
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel Orientation="Horizontal" MaxWidth="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type ListBox}}, Path=ActualWidth}" />
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
</ListBox>
<GroupBox Name="pageBox" IsEnabled="{Binding Visible}" Grid.Row="1" DataContext="{Binding Path=SelectedValue, ElementName=listView}">
<GroupBox.Header>
<Label Content="{Binding Name}" Padding="0"/>
</GroupBox.Header>
<ContentControl Content="{Binding}"/>
</GroupBox>
</Grid>
If the notification of IsAlerting property change (via INotifyPropertyChange) is fired approximately one time per second, the memory usage of my application increases from 230MB up to 804MB for 15 minutes and the application finally crashes with the following call stack:
Exception Info: System.Reflection.TargetInvocationException
Stack:
at System.Windows.FrameworkTemplate.LoadTemplateXaml(System.Xaml.XamlReader, System.Xaml.XamlObjectWriter)
at System.Windows.FrameworkTemplate.LoadTemplateXaml(System.Xaml.XamlObjectWriter)
at System.Windows.FrameworkTemplate.LoadOptimizedTemplateContent(System.Windows.DependencyObject, System.Windows.Markup.IComponentConnector, System.Windows.Markup.IStyleConnector, System.Collections.Generic.List`1<System.Windows.DependencyObject>, System.Windows.UncommonField`1<System.Collections.Hashtable>)
at System.Windows.FrameworkTemplate.LoadContent(System.Windows.DependencyObject, System.Collections.Generic.List`1<System.Windows.DependencyObject>)
at System.Windows.StyleHelper.ApplyTemplateContent(System.Windows.UncommonField`1<System.Collections.Specialized.HybridDictionary[]>, System.Windows.DependencyObject, System.Windows.FrameworkElementFactory, Int32, System.Collections.Specialized.HybridDictionary, System.Windows.FrameworkTemplate)
at System.Windows.FrameworkTemplate.ApplyTemplateContent(System.Windows.UncommonField`1<System.Collections.Specialized.HybridDictionary[]>, System.Windows.FrameworkElement)
at System.Windows.FrameworkElement.ApplyTemplate()
at System.Windows.FrameworkElement.MeasureCore(System.Windows.Size)
at System.Windows.UIElement.Measure(System.Windows.Size)
at System.Windows.ContextLayoutManager.UpdateLayout()
at System.Windows.ContextLayoutManager.UpdateLayoutCallback(System.Object)
at System.Windows.Media.MediaContext+InvokeOnRenderCallback.DoWork()
at System.Windows.Media.MediaContext.FireInvokeOnRenderCallbacks()
at System.Windows.Media.MediaContext.RenderMessageHandlerCore(System.Object)
at System.Windows.Media.MediaContext.RenderMessageHandler(System.Object)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(System.Delegate, System.Object, Int32)
.............
any ideas?

Answer 1

Not sure about the memory leak, but i wouldn't change the contenttemplate like this. If you set the ContentTemplate on a ContentPresenter, the ContentSource property of the ContentPresenter (which is 'Content' by default) will be overruled/ignored, the Content property will be empty, and your ContentTemplate doesn't have a datacontext anymore.
It's better to set the ContentTemplate in a style setter and use style triggers to change it. The default ContentSource of the ContentPresenter will do the rest.
I suspect this might solve your memory leak.

Answer 2

Your memory leak may be caused by the situation described in Can bindings create memory leaks in WPF?, perhaps exacerbated by virtualization in the list box (or maybe lack thereof if you have a lot of items and it is allocating them all at once). The fact that you have a System.Reflection.TargetInvocationException makes me think you are binding to something that isn't an INotifyPropertyChanged, which then has to use reflection to figure out if values are changing.
In newer versions of Visual Studio (2013, maybe 2012), there is a memory profiler that can show what objects are leaking which may help you narrow your search.

Answer 3

for some reason moving MultiDataTrigger to a separate style solved the problem (there is no memory leak anymore):
<Style TargetType="{x:Type ContentControl}" x:Key="PageToolHeaderContentControlThemeStyle">
<Setter Property="Foreground" Value="{StaticResource ForegroundBrush}"/>
<Setter Property="Padding" Value="5,3"/>
....
<ControlTemplate.Triggers>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding Alert}" Value="Warning"/>
<Condition Binding="{Binding IsAcknowledged}" Value="True"/>
</MultiDataTrigger.Conditions>
<MultiDataTrigger.Setters>
<Setter TargetName="PART_BorderAlarmFrame" Property="Stroke" Value="Orange"/>
<Setter TargetName="PART_BorderAlarmFrame" Property="Visibility" Value="Visible"/>
</MultiDataTrigger.Setters>
</MultiDataTrigger>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding Alert}" Value="Warning"/>
<Condition Binding="{Binding IsAcknowledged}" Value="False"/>
</MultiDataTrigger.Conditions>
<MultiDataTrigger.Setters>
<Setter TargetName="PART_BorderAlarmFrame" Property="Visibility" Value="Visible"/>
</MultiDataTrigger.Setters>
<MultiDataTrigger.EnterActions>
<BeginStoryboard>
<Storyboard>
<ColorAnimation Storyboard.TargetName="BackgroundBrush"
Storyboard.TargetProperty="Color"
From="Transparent" To="Orange" Duration="0:0:0.5"
AutoReverse="True"
RepeatBehavior="Forever" />
</Storyboard>
</BeginStoryboard>
</MultiDataTrigger.EnterActions>
</MultiDataTrigger>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding Alert}" Value="Alarm"/>
<Condition Binding="{Binding IsAcknowledged}" Value="True"/>
</MultiDataTrigger.Conditions>
<MultiDataTrigger.Setters>
<Setter TargetName="PART_BorderAlarmFrame" Property="Stroke" Value="Red"/>
<Setter TargetName="PART_BorderAlarmFrame" Property="Visibility" Value="Visible"/>
</MultiDataTrigger.Setters>
</MultiDataTrigger>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding Alert}" Value="Alarm"/>
<Condition Binding="{Binding IsAcknowledged}" Value="False"/>
</MultiDataTrigger.Conditions>
<MultiDataTrigger.Setters>
<Setter TargetName="PART_BorderAlarmFrame" Property="Visibility" Value="Visible"/>
</MultiDataTrigger.Setters>
<MultiDataTrigger.EnterActions>
<BeginStoryboard>
<Storyboard>
<ColorAnimation Storyboard.TargetName="BackgroundBrush"
Storyboard.TargetProperty="Color"
From="Transparent" To="Red" Duration="0:0:0.5"
AutoReverse="True"
RepeatBehavior="Forever" />
</Storyboard>
</BeginStoryboard>
</MultiDataTrigger.EnterActions>
</MultiDataTrigger>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Foreground" Value="{DynamicResource LightForegroundBrush}"/>
<Setter TargetName="PART_BorderDefaultFrame" Property="Stroke" Value="{StaticResource ButtonPressedBackgroundBrush}"/>
<Setter TargetName="PART_Border" Property="Background" Value="{StaticResource ButtonHoverBackgroundBrush}"/>
</Trigger>
<DataTrigger Binding="{Binding IsSelected}" Value="True">
<Setter Property="Foreground" Value="{DynamicResource LightForegroundBrush}"/>
<Setter TargetName="PART_BorderDefaultFrame" Property="Stroke" Value="{StaticResource ButtonPressedBackgroundBrush}"/>
<Setter TargetName="PART_Border" Property="Background" Value="{StaticResource ButtonPressedBackgroundBrush}"/>
</DataTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>