StateListAnimator w / AppBarLayout

Question

将高程值应用于AppBarLayout时遇到问题。

我知道，应用常量高程值的代码看起来很简单：

stateListAnimator.addState(IntArray(0), ObjectAnimator.ofFloat(layoutAppBar, "elevation", someElevationValue))
layoutAppBar.stateListAnimator = stateListAnimator

所以我将此代码放在 layoutAppBar.addOnOffsetChangedListener 中并更新高程值：

val appBarElevationCurrent = (currentPercent * appBarElevationMax) / 100
stateListAnimator.addState(IntArray(0), ObjectAnimator.ofFloat(layoutAppBar, "elevation", appBarElevationCurrent))
layoutAppBar.stateListAnimator = stateListAnimator

在这种情况下，高程值不会改变。你有什么想法，我怎么能让它发挥作用。

提前谢谢。

Answer 1

刚想通了，stateListAnimator的初始化

val stateListAnimator = StateListAnimator()

必须在侦听器内部。 完整的代码段：

 layoutAppBar.addOnOffsetChangedListener { _, verticalOffset ->
            val currentPercent = Math.abs(verticalOffset) * 100 / Math.abs(layoutAppBar.totalScrollRange + 1)
            val appBarElevationCurrent = (currentPercent * appBarElevationMax) / 100

            val stateListAnimator = StateListAnimator()
            stateListAnimator.addState(IntArray(0), ObjectAnimator.ofFloat(layoutAppBar, "elevation", appBarElevationCurrent))
            layoutAppBar.stateListAnimator = stateListAnimator
        }