Can the Picker signal my VM when it gains focus?

Does a 'focused' event fire before 'unfocused'? I tried to move the trigger from one control over to the picker control, but I get errors when the events are fired. The build is fine, and everything works until the picker gains control. It then crashes.

FWIW, here is the code for the picker (with trigger):

<br /><Picker ItemsSource="{Binding myList}" Title="Select one" SelectedItem="{Binding myItem}">
    <Picker.Triggers>
        <EventTrigger Event="Focused">
            <local:FocusedTriggerAction />
        </EventTrigger>
    </Picker.Triggers>
    <Picker.ItemDisplayBinding>
        <Binding Path="FullName"/>
    </Picker.ItemDisplayBinding>
</Picker>