Динамическое создание объектов в WPF при событии drag and drop.

private void Rectangle_Drop(object sender, DragEventArgs e)
        {
            i++;
            myButton = new Button();
            myButton.Content = "Drop Button";
            myButton.Height = 25;
            myButton.Width = 120;
            myButton.Name = "simple";
            myButton.VerticalAlignment = System.Windows.VerticalAlignment.Top;
            myButton.HorizontalAlignment = System.Windows.HorizontalAlignment.Left;
            myButton.Margin = new Thickness(coordinate.X + 12, coordinate.Y + 48, 0, 0);
            myButton.Content = "Button" + i;
            myButton.GotFocus += new RoutedEventHandler(myButton_GetFocus);
            myGrid.Children.Add(myButton);
        }

namespace WPF_example
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
   
    public partial class MainWindow : Window
    {

        private Button[] myButton= new Button[20];
        Point coordinate;
        int i=0;
        public MainWindow()
        {
            InitializeComponent();
        }

        private bool isDragStarted;

        private void Rectangle_Drop(object sender, DragEventArgs e)
        {
            i++;
            myButton = new Button();
            myButton.Content = "Drop Button";
            myButton.Height = 25;
            myButton.Width = 120;
            myButton.Name = "simple";
            myButton.VerticalAlignment = System.Windows.VerticalAlignment.Top;
            myButton.HorizontalAlignment = System.Windows.HorizontalAlignment.Left;
            myButton.Margin = new Thickness(coordinate.X + 12, coordinate.Y + 48, 0, 0);
            myButton.Content = "Button" + i;
            myButton.GotFocus += new RoutedEventHandler(myButton_GetFocus);
            myGrid.Children.Add(myButton);
        }

        private void myButton_GetFocus(object sender, RoutedEventArgs e)
        {
            MessageBox.Show(e.OriginalSource.ToString());
            Button btn = (Button)e.OriginalSource;
            btn.Content = "work";
        }

        private void testButton_PreviewMouseDown(object sender, MouseButtonEventArgs e)
        {
            if (e.LeftButton == MouseButtonState.Pressed)
            {
                this.isDragStarted = true;
            }
        }

        private void testButton_PreviewMouseMove(object sender, MouseEventArgs e)
        {
            if (this.isDragStarted)
            {
                DataObject data = new DataObject("Button");
                DragDrop.DoDragDrop(this.testButton, data, DragDropEffects.Move);
                this.isDragStarted = false;
            }
        }


        private void Rectangle_DropOver(object sender, DragEventArgs e)
        {
            coordinate = e.GetPosition(myRectangle);
        }

    }
}