c# wpf 错误 (System.InvalidOperationException)

Question

namespace WpfApplication1
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        Random random = new Random();

        public MainWindow()
        {
            InitializeComponent();
        }

        private void startButton_Click(object sender, RoutedEventArgs e)
        {
            addEnemy();
        }

        private void addEnemy()
        {
            ContentControl enemy = new ContentControl();
            enemy.Template = Resources["EnemyTemplate"] as ControlTemplate;
            AnimateEnemy(enemy, 0, playArea.ActualWidth - 100, "(canvas.left)");
            AnimateEnemy(enemy, random.Next((int)playArea.ActualHeight - 100), 
                random.Next((int)playArea.ActualHeight - 100), "(canvas.top)");
            playArea.Children.Add(enemy);
        }

        private void AnimateEnemy(ContentControl enemy, double from, double to, string propertyToAnimate)
        {
            Storyboard storyboard = new Storyboard() { AutoReverse = true, RepeatBehavior = RepeatBehavior.Forever };
            DoubleAnimation animation = new DoubleAnimation()
            {
                From = from,
                To = to,
                Duration = new Duration(TimeSpan.FromSeconds(random.Next(4, 6))),
            };
            Storyboard.SetTarget(animation, enemy);
            Storyboard.SetTargetProperty(animation, new PropertyPath(propertyToAnimate));
            storyboard.Children.Add(animation);
              //problem
            storyboard.Begin();
        }

    }

$ My error(An unhandled exception of type 'System.InvalidOperationException' occurred in PresentationFramework.dll

Additional information: Cannot resolve all property references in the property path '(canvas.left)'. Verify that applicable objects support the properties.)

can somebody help me with this?

Answer 1

Property names are case-sensitive. It should be C anvas. L eft and C anvas. T op:

private void addEnemy()
{
    ContentControl enemy = new ContentControl();
    enemy.Template = Resources["EnemyTemplate"] as ControlTemplate;
    AnimateEnemy(enemy, 0, playArea.ActualWidth - 100, "(Canvas.Left)");
    AnimateEnemy(enemy, random.Next((int)playArea.ActualHeight - 100),
        random.Next((int)playArea.ActualHeight - 100), "(Canvas.Top)");
    playArea.Children.Add(enemy);
}