MainPage.xaml

<Page
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:App11"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:Interactivity="using:Microsoft.Xaml.Interactivity" xmlns:Core="using:Microsoft.Xaml.Interactions.Core" xmlns:Media="using:Microsoft.Xaml.Interactions.Media"
    x:Class="App11.MainPage"
    mc:Ignorable="d">
	<Page.Resources>
		<Storyboard x:Name="Storyboard1">
			<DoubleAnimation Duration="0:0:1" To="391.184" Storyboard.TargetProperty="(UIElement.RenderTransform).(CompositeTransform.TranslateX)" Storyboard.TargetName="button" d:IsOptimized="True"/>
			<DoubleAnimation Duration="0:0:1" To="403.762" Storyboard.TargetProperty="(UIElement.RenderTransform).(CompositeTransform.TranslateY)" Storyboard.TargetName="button" d:IsOptimized="True"/>
		</Storyboard>
	</Page.Resources>
    <Page.DataContext>
        <local:MainPageViewModel />
    </Page.DataContext>

	<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
		<Interactivity:Interaction.Behaviors>
			<local:StoryboardCompletedTrigger TargetStoryboard="{StaticResource Storyboard1}">
				<local:StoryboardCompletedTrigger.Actions>
					<Core:InvokeCommandAction Command="{Binding StoryboardCompletedCommand, Mode=OneWay}"/>
				</local:StoryboardCompletedTrigger.Actions>
			</local:StoryboardCompletedTrigger>
		</Interactivity:Interaction.Behaviors>
		<Button x:Name="button" Content="{Binding Message}" HorizontalAlignment="Left" Margin="79,57,0,0" VerticalAlignment="Top" RenderTransformOrigin="0.5,0.5">
			<Button.RenderTransform>
				<CompositeTransform/>
			</Button.RenderTransform>
			<Interactivity:Interaction.Behaviors>
				<Core:EventTriggerBehavior EventName="Click">
					<Media:ControlStoryboardAction Storyboard="{StaticResource Storyboard1}"/>
				</Core:EventTriggerBehavior>
			</Interactivity:Interaction.Behaviors>
		</Button>

	</Grid>
</Page>

StoryboardBehavior.cs

using Microsoft.Xaml.Interactivity;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Media.Animation;

namespace App11
{
    public class StoryboardCompletedTrigger : DependencyObject, IBehavior
    {
        public ActionCollection Actions
        {
            get 
            {
                var result = (ActionCollection)GetValue(ActionsProperty); 
                if (result == null)
                {
                    result = new ActionCollection();
                    this.Actions = result;
                }

                return result;
            }
            set { SetValue(ActionsProperty, value); }
        }

        // Using a DependencyProperty as the backing store for Actions.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty ActionsProperty =
            DependencyProperty.Register("Actions", 
                typeof(ActionCollection), 
                typeof(StoryboardCompletedTrigger), 
                new PropertyMetadata(null));



        public Storyboard TargetStoryboard
        {
            get { return (Storyboard)GetValue(TargetStoryboardProperty); }
            set { SetValue(TargetStoryboardProperty, value); }
        }

        public static readonly DependencyProperty TargetStoryboardProperty =
            DependencyProperty.Register("TargetStoryboard", 
                typeof(Storyboard), 
                typeof(StoryboardCompletedTrigger), 
                new PropertyMetadata(null));


        public DependencyObject AssociatedObject { get; set; }

        public void Attach(DependencyObject associatedObject)
        {
            if (this.TargetStoryboard == null)
            {
                return;
            }

            this.TargetStoryboard.Completed += TargetStoryboard_Completed;
        }

        private void TargetStoryboard_Completed(object sender, object e)
        {
            Interaction.ExecuteActions(this, this.Actions, e);
        }

        public void Detach()
        {
        }
    }

}