Question

I would like my ads to be shown while my app is trialed and disappear when app is fully licensed.

Kookiz-

Private Sub PhoneApplicationPage_Loaded(sender As System.Object, e As System.Windows.RoutedEventArgs)

    If App.IsTrial Then
        AdControl1.Visibility = Windows.Visibility.Visible

    Else
        AdControl1.Visibility = Windows.Visibility.Collapsed
    End If

End Sub

Answer 1

The problem is that IsEnabled still shows the Control.

What you should do is add an empty container for the ad in your XAML file, like this:

<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>            
    <StackPanel x:Name="spAd" Grid.Row="0">
        <!--Ad will be placed here via the code-->
    </StackPanel>   
</Grid>

Then in the PhoneApplicationPage_Loaded event handler, if IsTrial equals true, instanciate the AdControl and add it to the View:

AdControl _adControl = new AdControl();

// Use your real Application ID and Ad Unit ID here
_adControl.ApplicationId = "test_client";
_adControl.AdUnitId = "Image480_80"; 

_adControl.Width = 480;
_adControl.Height = 80;

spAd.Children.Add(_adControl);