WpfToolkit AutoCompleteBox style trigger IsFocused NOT firing - wpf

Question

I am using the latest version of WPF Toolkit. I am trying to style an AutoCompleteBox and I can't seem to get the "IsFocused" trigger to work. Basically I want it to behave like my TextBox style so I made one for the AutoCompleteBox. I even tried assigning my TextBox style to the TextBoxStyle property of the AutoCompleteBox and I still never see the IsFocused trigger fire.
I did try playing around in the code behind and noticed that if I override OnGotFocus and OnLostFocus those never get called. But if I wire some event handlers to the GotFocus and LostFocus events, THEN I finally see something happen. If wiring to the events is the only way to see the IsFocused change then that seems like an ugly hack. Is there some work around for this or something I should do different?
My TexBox Style
<Style TargetType="TextBox" x:Key="TextBoxStyle">
<Setter Property="Background" Value="{StaticResource TextBoxBackground}"/>
<Setter Property="Foreground" Value="{StaticResource Foreground}"/>
<Setter Property="CaretBrush" Value="{StaticResource Foreground}"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type TextBox}">
<Grid Background="{TemplateBinding Background}" SnapsToDevicePixels="true">
<ScrollViewer x:Name="PART_ContentHost" Margin="1"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsMouseOver" Value="true">
<Setter Property="Background" Value="{StaticResource TextBoxBackgroundSelected}"/>
</Trigger>
<Trigger Property="IsFocused" Value="true">
<Setter Property="Background" Value="{StaticResource TextBoxBackgroundSelected}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
My AutoCompleteBox Style
<Style TargetType="WpfToolkitInput:AutoCompleteBox" x:Key="AutoCompleteBoxStyle">
<Setter Property="Background" Value="{StaticResource TextBoxBackground}"/>
<Setter Property="Foreground" Value="{StaticResource Foreground}"/>
<Setter Property="BorderThickness" Value="0"/>
<Setter Property="TextBoxStyle" Value="{StaticResource TextBoxStyle}"/>
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="true">
<Setter Property="Background" Value="{StaticResource TextBoxBackgroundSelected}"/>
</Trigger>
<Trigger Property="IsFocused" Value="true">
<Setter Property="Background" Value="{StaticResource TextBoxBackgroundSelected}"/>
</Trigger>
</Style.Triggers>
Any ideas?
Thank you for your time!

Answer 1

I was unsuccessful in finding an elegant solution to the problem. I ended up inheriting from AutoCompleteBox and performing my logic with the event handlers.
public class AutoCompleteTextBox : AutoCompleteBox
...
public AutoCompleteTextBox()
{
// Register the event handler for GotFocus.
base.GotFocus += this.AutoCompleteTextBoxGotFocus;
// Register the event handler for LostFocus.
base.LostFocus += this.AutoCompleteTextBoxLostFocus;
}
Nothing fancy here. I just made my own type. The only thing I do is wire up the got and lost focused event handlers in the constructor. I'm not sure why but the IsFocused trigger does not pick up these events. Also, if you try to override these: "OnGotFocus" or "OnLostFocus", they don't work either. So the only way I could find if the AutoCompleteBox is focused is to register directly to the event. If someone comes across this in the future and has a better way, please comment.