Question

I can trigger property settings on my ListBoxItem template based on properties of underlying data object using DataTrigger with something like this

<DataTrigger Binding='{Binding Path=IsMouseOver}' Value='true'>   <Setter TargetName='ItemText' Property='TextBlock.TextDecorations' Value='Underline'>   </Setter> </DataTrigger> 

But what if I want to do the opposite? I mean set a property value on the underlying data object based on property value of my ListBoxItem. Something like:

<Trigger Property='IsMouseOver' Value='True'>   <Setter Property='MyClass.IsHilited' Value='True'></Setter> </Trigger> 

Is there a mechanism for something like this or what would be the recommended approach to deal with situations like this?

Thanks.

Answer 1

I think that you could use an EventSetter to do in XAML what Josh G suggested in code. Maybe create one for the MouseEnter and MouseLeave events, and style the control appropriately for each?

Update: You can set up the events like this:

<ListBox>     <ListBox.Resources>         <Style TargetType='{x:Type ListBoxItem}'>             <EventSetter Event='MouseEnter' Handler='OnListBoxItemMouseEnter' />             <EventSetter Event='MouseLeave' Handler='OnListBoxItemMouseLeave' />         </Style>     </ListBox.Resources>     <ListBoxItem>Item 1</ListBoxItem>     <ListBoxItem>Item 2</ListBoxItem>     <ListBoxItem>Item 3</ListBoxItem>     <ListBoxItem>Item 4</ListBoxItem>     <ListBoxItem>Item 5</ListBoxItem> </ListBox> 

The Style registers for the MouseEnter and MouseLeave events for all ListBoxItems defined in that ListBox.

And then in your code behind file:

private void OnListBoxItemMouseEnter(object sender, RoutedEventArgs e) {     ListBoxItem lvi = sender as ListBoxItem;     if(null != lvi)     {         lvi.Foreground = new SolidColorBrush(Colors.Red);     } }  private void OnListBoxItemMouseLeave(object sender, RoutedEventArgs e) {     ListBoxItem lvi = sender as ListBoxItem;     if(null != lvi)     {         lvi.Foreground = new SolidColorBrush(Colors.Black);     } } 

These handlers set the color of the text of the ListBoxItem to red when the mouse is over the item, and back to black when the mouse leaves it.