当动画停止播放时发生。

Occurs whenever the animation stops playing.

youdao

如果玩家释放了鼠标左键，循环就会停止。但是你应该不想让动画在播放到一般的时候就突然中断。

If the player lets the mouse button go, it will stop, but you do not want to stop right away since the animation will pop in the middle of the loop.

youdao

也就是说这个方法其实是反转动画，如果动画正在播放，这个方法停止动画，并从当前点往回播。

Plays the ValueAnimator in reverse. If the animation is already running, it will stop itself and play backwards from the point reached when reverse was called.

youdao