How do you get ListBoxItem.IsMouseCaptured to trigger style changes? - wpf

Question

I'm using the following style:
<Style x:Key="ListBoxItemStyle" TargetType="{x:Type ListBoxItem}">
<Setter Property="Foreground" Value="{DynamicResource Button-Foreground}"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ListBoxItem}">
<TextBlock Padding="10"
Background="{TemplateBinding Background}"
Foreground="{TemplateBinding Foreground}">
<ContentPresenter/>
</TextBlock>
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Foreground" Value="{DynamicResource Button-Foreground-Disabled}"/>
</Trigger>
<Trigger Property="IsMouseCaptured" Value="True">
<Setter Property="Background" Value="{DynamicResource Button-Background-Hover}"/>
<Setter Property="Foreground" Value="{DynamicResource Button-Foreground}"/>
</Trigger>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition Property="IsMouseOver" Value="True"/>
<Condition Property="IsMouseCaptured" Value="False"/>
</MultiTrigger.Conditions>
<Setter Property="Background" Value="{DynamicResource Button-Background-Hover}"/>
<Setter Property="Foreground" Value="{DynamicResource Button-Foreground-Hover}"/>
</MultiTrigger>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition Property="IsSelected" Value="True"/>
<Condition Property="IsMouseOver" Value="False"/>
</MultiTrigger.Conditions>
<Setter Property="Background" Value="{DynamicResource Button-Foreground}"/>
<Setter Property="Foreground" Value="{DynamicResource Button-Foreground-Hover}"/>
</MultiTrigger>
</Style.Triggers>
</Style>
The issue I'm having is that the IsMouseCaptured trigger never occurs. It keeps the IsMouseOver style even when I clicked it (the background is the same color intentionally, but I've tried changing just to experiment and it doesn't change at all and the foreground certainly doesn't change).
Is there a way to have triggers occur for a specific list box item when it is clicked? All the other triggers are working as expected.

Answer 1

Is there a way to have triggers occur for a specific list box item when it is clicked?
Not using any built-in property.
You could create your own custom ListBoxItem that adds an IsPressed property that you can bind to:
public class CustomListBoxItem : ListBoxItem
{
public static readonly DependencyProperty IsPressedProperty = DependencyProperty.Register(
nameof(IsPressed), typeof(bool), typeof(CustomListBoxItem), new PropertyMetadata(false));
public bool IsPressed
{
get => (bool)GetValue(IsPressedProperty);
set => SetValue(IsPressedProperty, value);
}
protected override void OnMouseDown(MouseButtonEventArgs e)
{
base.OnMouseDown(e);
IsPressed = true;
}
protected override void OnMouseUp(MouseButtonEventArgs e)
{
base.OnMouseUp(e);
IsPressed = false;
}
}
Unless you create the ListBoxItem elements explicitly, you will also need a custom ListBox that generates containers of your custom type:
public class CustomListBox : ListBox
{
protected override DependencyObject GetContainerForItemOverride() =>
new CustomListBoxItem();
}