WPF 中的颜色过渡

我想要进行颜色过渡BackgroundWPF 窗口的颜色。

我怎样才能做到这一点？

例如：

Brush i_color = Brushes.Red; //this is the initial color
Brush f_color = Brushes.Blue; //this is the final color

当我点击Button button1

private void button1_Click(object sender, RoutedEventArgs e)
{
    this.Background = f_color; //here the transition begins. I don't want to be quick. Maybe an interval of 4 seconds.
}

在代码中可以用这个来完成

private void button1_Click(object sender, RoutedEventArgs e)
{
    ColorAnimation ca = new ColorAnimation(Colors.Red, Colors.Blue, new Duration(TimeSpan.FromSeconds(4)));
    Storyboard.SetTarget(ca, this);
    Storyboard.SetTargetProperty(ca, new PropertyPath("Background.Color"));

    Storyboard stb = new Storyboard();
    stb.Children.Add(ca);
    stb.Begin();
}

正如 H.B.指出这也会起作用

private void button1_Click(object sender, RoutedEventArgs e)
{
    ColorAnimation ca = new ColorAnimation(Colors.Blue, new Duration(TimeSpan.FromSeconds(4)));
    this.Background = new SolidColorBrush(Colors.Red);
    this.Background.BeginAnimation(SolidColorBrush.ColorProperty, ca);
}