WPF Button

参考：

https://blog.csdn.net/qq_43024228/article/details/104886221

https://www.cnblogs.com/xiaomingg/p/8699125.html

 动画效果：

<Window.Resources>
        <Style TargetType="Button">
            <Style.Triggers>
                <!--事件触发器-->
                <EventTrigger RoutedEvent="MouseEnter">
                    <BeginStoryboard>
                        <Storyboard>
                            <DoubleAnimation Storyboard.TargetProperty="Opacity" From="1" To="0.1" Duration="0:0:3"></DoubleAnimation>
                        </Storyboard>
                    </BeginStoryboard>
                </EventTrigger>
            </Style.Triggers>
        </Style>
    </Window.Resources>