public void Intercanvi(ref int primer, ref int segon, int a, int b)
        {
            int temp;
            DoEvents();
            temp = primer;
            primer = segon;
            segon = temp;
            rectangles[a].Fill = canvi;
            rectangles[b].Fill = canvi;
            DoAnimacio(a, b);
            Espera(Convert.ToInt32(iudPausa.Value));
            if (cmbPuntsBarres.SelectedIndex == 0)
            {
                double heightA = rectangles[a].Height;
                rectangles[a].Height = rectangles[b].Height;
                rectangles[b].Height = heightA;
            }
            else
            {
                double bottom = Canvas.GetBottom(rectangles[a]);
                Canvas.SetBottom(rectangles[a], Canvas.GetBottom(rectangles[b]));
                Canvas.SetBottom(rectangles[b], bottom);
            }
            ComprobarFigura(a, primer);
            ComprobarFigura(b, segon);
        }

        private void DoAnimacio(int a, int b)
        {
            DoubleAnimation animacio = new DoubleAnimation();
            //ElasticEase ease = new ElasticEase();
            //ease.EasingMode = EasingMode.EaseOut;
            //animacio.EasingFunction = ease;
            animacio.Duration = TimeSpan.FromMilliseconds((double)iudPausa.Value);
            PutEasing(ref animacio);
            switch (cmbTipusAnimacio.SelectedIndex)
            {
                case 0:
                    if (cmbPuntsBarres.SelectedIndex == 0)
                    {
                        animacio.From = rectangles[a].Height;
                        animacio.To = rectangles[b].Height;
                        rectangles[a].BeginAnimation(Shape.HeightProperty, animacio);

                        animacio.From = rectangles[b].Height;
                        animacio.To = rectangles[a].Height;
                        rectangles[b].BeginAnimation(Shape.HeightProperty, animacio);
                    }
                    else
                    {
                        animacio.From = Canvas.GetBottom(rectangles[a]);
                        animacio.To = Canvas.GetBottom(rectangles[b]);
                        rectangles[a].BeginAnimation(Canvas.BottomProperty, animacio);

                        animacio.From = Canvas.GetBottom(rectangles[b]);
                        animacio.To = Canvas.GetBottom(rectangles[a]);
                        rectangles[b].BeginAnimation(Canvas.BottomProperty, animacio);
                    }
                        break;
                case 1:
                    Canvas.SetZIndex(rectangles[a], 1);
                    Canvas.SetZIndex(rectangles[b], 1);
                    animacio.FillBehavior = FillBehavior.Stop;
                    animacio.From = Canvas.GetLeft(rectangles[a]);
                    animacio.To = Canvas.GetLeft(rectangles[b]);
                    rectangles[a].BeginAnimation(Canvas.LeftProperty, animacio);

                    animacio.From = Canvas.GetLeft(rectangles[b]);
                    animacio.To = Canvas.GetLeft(rectangles[a]);
                    rectangles[b].BeginAnimation(Canvas.LeftProperty, animacio);
                    break;
            }
        }