c# - 倾斜动画无法动画

Question

我在将倾斜动画转换为双重动画类方面取得了进展。剩下的唯一问题是当调度计时器调用动画时，会抛出一个错误。错误如下...

Cannot animate the 'AngleX' property on 'System.Windows.Media.MatrixTransform' because the object is sealed or frozen.

我将如何克服这个错误以使动画可以工作？

    public static void Grass(Canvas canvas, int boundry)
    {
        foreach (var element in canvas.Children.OfType<Image>())
        {
            if (element.Name == "GrassForeground" || element.Name == "GrassBackground")
            {
                var skewGrass = new DoubleAnimation
                {
                    From = 0,
                    To = 10,
                    EasingFunction = new BackEase(),
                    AutoReverse = true
                };
                var transform = (MatrixTransform)element.RenderTransform;
                transform.BeginAnimation(SkewTransform.AngleXProperty, skewGrass);
            }
        }
    }

Answer 1

试试下面这个，或者你有特殊的理由使用 MatrixTransform？

public static void Grass(Canvas canvas, int boundry)
{
    foreach (var element in canvas.Children.OfType<Image>())
    {
        if (element.Name == "GrassForeground" || element.Name == "GrassBackground")
        {
            var skewGrass = new DoubleAnimation
            {
                Duration = new Duration(TimeSpan.FromSeconds(5)),
                From = 0,
                To = 10,
                EasingFunction = new BackEase(),
                AutoReverse = true
            };
            element.RenderTransform = new SkewTransform();
            element.RenderTransform.BeginAnimation(SkewTransform.AngleXProperty, skewGrass);
        }
    }
}