I have a dependency property in my user control called `IsPromptShown`:

```
public static DependencyProperty IsPromptShownProperty = DependencyProperty.
    Register("IsPromptShown", typeof(bool), typeof(AutoCompleteSearchBox), new 
    PropertyMetadata(true));

public bool IsPromptShown
{
    get { return (bool)GetValue(IsPromptShownProperty); }
    set { SetValue(IsPromptShownProperty, value); }
}

```

That custom control contains a `TextBox`. That text box doesn't have any value assigned to its `Text` property:

```
<TextBox Name="_searchTextBox" Grid.Row="0" VerticalAlignment="Top" 
    GotFocus="SearchTextBox_GotFocus" LostFocus="SearchTextBox_LostFocus" 
    TextChanged="SearchTextBox_TextChanged"/>

```

Now I'm setting the following trigger in the hosting window:

```
<Trigger Property="IsPromptShown" Value="True">
    <!--<Setter Property="FontStyle" Value="Italic"/>-->
    <Setter Property="TextBox.Text" Value="Seek"/>
</Trigger>

```

The commented line that sets `FontStyle` works but the second that sets `TextBox.Text` doesn't. I also have been trying to set `Foreground` property and that also have failed. What is going on?