安卓：ViewPager2速度可控地翻页一次代码

安卓：ViewPager2速度可控地翻页一次代码

// 更加平滑
fun ViewPager2.startFakeScroll() {
    if (!this.beginFakeDrag()) return

    val animator = ValueAnimator.ofFloat(0f, -this.width.toFloat())
    // 拖动速度ms，可调整
    animator.duration = 400
    animator.interpolator = LinearInterpolator()
    var lastValue = 0f

    animator.addUpdateListener {
        val currentValue = it.animatedValue as? Float ?: return@addUpdateListener
        val delta = currentValue - lastValue
        this.fakeDragBy(delta)
        lastValue = currentValue
    }

    animator.addListener(object : AnimatorListenerAdapter() {
        override fun onAnimationEnd(animation: Animator) {
            this@startFakeScroll.endFakeDrag()
        }
    })

    animator.start()
}