Question

I have a mouseover-selecting listview by using trigger:

<ListView.ItemContainerStyle>
    <Style TargetType="{x:Type ListViewItem}">
        <Style.Triggers>
            <Trigger Property="IsMouseOver" Value="True">
                <Setter Property="IsSelected" Value="True" />
            </Trigger>
        </Style.Triggers>
    </Style>
</ListView.ItemContainerStyle>

However when mouse is moved out, the trigger sets IsSelected back to false, which is not desired here. Is there a way to make a trigger only set-upon-enter but not reset-upon-exit?

Answer 1

This is what EventTriggers are for:

Unlike Trigger, EventTrigger has no concept of termination of state, so the action will not be undone once the condition that raised the event is no longer true.

In your case for example:

<EventTrigger RoutedEvent="MouseEnter">
    <BeginStoryboard>
        <Storyboard>
            <BooleanAnimationUsingKeyFrames Storyboard.TargetProperty="IsSelected">
                <DiscreteBooleanKeyFrame KeyTime="0" Value="True" />
            </BooleanAnimationUsingKeyFrames>
        </Storyboard>
    </BeginStoryboard>
</EventTrigger>