1.前臺(tái)切換到后臺(tái)

activity.moveTaskToBack(true)
activity.overridePendingTransition(R.anim.slide_right_in, R.anim.empyt_anim)

R.anim.slide_right_in

<set xmlns:android="http://schemas.android.com/apk/res/android" >
    <translate
        android:duration="200"
        android:fromXDelta="100.0%p"
        android:toXDelta="0.0%p" />
</set>

R.anim.empyt_anim

<set xmlns:android="http://schemas.android.com/apk/res/android">
    <translate
        android:duration="200"
        android:fromXDelta="0.0%p"
        android:toXDelta="0.0%p" />
</set>

2.后臺(tái)切換到前臺(tái)(比較笨的方法，但是可行)

val manager = activity.getSystemService(Service.ACTIVITY_SERVICE) as ActivityManager
            AppStateComponent.topActivity?.let {
                manager.moveTaskToFront(it.taskId, 0)
                checkTaskDisposable = Observable.intervalRange(1, 5, 0, 1, TimeUnit.SECONDS).subscribe { aLong ->
                    if (AppStateComponent.state.value == AppStateComponent.STATE_FOREGROUND) {
                        checkTaskDisposable?.dispose()
                    } else {
                        manager.moveTaskToFront(it.taskId, 0)
                    }
                }
            }