棉花糖上的不同AnimatedVectorDrawable (shapeshifter动画，涉及androidx )

Question

我的动画代码崩溃了。它是从xml创建的动画：

<animated-vector
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:aapt="http://schemas.android.com/aapt">
    //not relevant
</animated-vector>

运行动画并崩溃的代码：

val animationDrawable = ContextCompat.getDrawable(context, R.drawable.anim_logbook_register_measurement)

    val callback = object : Animatable2Compat.AnimationCallback() {
        override fun onAnimationStart(drawable: Drawable?) {
            super.onAnimationStart(drawable)
            //not relevant
        }

        override fun onAnimationEnd(drawable: Drawable) {
            //not relevant
        }
    }

    AnimatedVectorDrawableCompat.registerAnimationCallback(animationDrawable, callback)
    animationCallback = callback
    (animationDrawable as? Animatable)?.start()

AnimatedVectorDrawableCompat.registerAnimationCallback(animationDrawable, callback)行发生崩溃，原因如下：

android.graphics.drawable.AnimatedVectorDrawable cannot be cast to androidx.vectordrawable.graphics.drawable.AnimatedVectorDrawableCompat

看起来ContextCompat.getDrawable在android6上创建了非androidx的AnimatedVectorDrawable，而AnimatedVectorDrawableCompat .registerAnimationCallback期望androidx one并崩溃。当查看AnimatedVectorDrawableCompat内部时，这一点变得很明显

public static void registerAnimationCallback(Drawable dr,
        Animatable2Compat.AnimationCallback callback) {
    if (dr == null || callback == null) {
        return;
    }
    if (!(dr instanceof Animatable)) {
        return;
    }

    if (Build.VERSION.SDK_INT >= 24) {
        registerPlatformCallback((AnimatedVectorDrawable) dr, callback);
    } else {
        ((AnimatedVectorDrawableCompat) dr).registerAnimationCallback(callback);
    }
} 

在我看来，line的Android bug，有人注意到这一点吗？有没有一种方法可以在从5开始的所有版本上工作？

Answer 1

这很糟糕，但如果我像这样从xml加载drawable，它显然是有效的：

val animationDrawable = return if (Build.VERSION.SDK_INT >= 24) {
        ContextCompat.getDrawable(this, R.drawable.anim_logbook_register_measurement)
    } else {
        AnimatedVectorDrawableCompat.create(this, R.drawable.anim_logbook_register_measurement)
    }