使用MotionLayout和MotionScene更改FAB背景色

<androidx.constraintlayout.motion.widget.MotionLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/ic_fab"
        android:backgroundTint="@color/fab_color" />

</androidx.constraintlayout.motion.widget.MotionLayout>

<MotionScene xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:motion="http://schemas.android.com/apk/res-auto">

    <Transition
        motion:constraintSetStart="@id/start"
        motion:constraintSetEnd="@id/end">

        <KeyFrameSet>
            <KeyAttribute
                motion:framePosition="0"
                motion:target="@id/fab"
                android:backgroundTint="@color/start_color" />

            <KeyAttribute
                motion:framePosition="100"
                motion:target="@id/fab"
                android:backgroundTint="@color/end_color" />
        </KeyFrameSet>

    </Transition>

    <ConstraintSet android:id="@+id/start">
        <!-- 定义FAB的起始状态 -->
        <Constraint
            android:id="@id/fab"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            motion:layout_constraintStart_toStartOf="parent"
            motion:layout_constraintTop_toTopOf="parent" />
    </ConstraintSet>

    <ConstraintSet android:id="@+id/end">
        <!-- 定义FAB的结束状态 -->
        <Constraint
            android:id="@id/fab"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            motion:layout_constraintEnd_toEndOf="parent"
            motion:layout_constraintBottom_toBottomOf="parent" />
    </ConstraintSet>

</MotionScene>

MotionLayout motionLayout = findViewById(R.id.motionLayout);
MotionScene motionScene = MotionSceneInflater.inflate(this, R.xml.motion_scene);
motionLayout.setTransition(motionScene);