android - MotionLayout - OnSwipe 不适用于 ViewPager2/RecyclerView

Question

onSwipe 手势不适用于 ViewPager2/RecyclerView，但是如果我用 ImageView 替换 ViewPager2/RecyclerView，它会开始正常工作。

activity_main.xml

<androidx.constraintlayout.motion.widget.MotionLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/motionLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layoutDescription="@xml/motion_scene">

    <androidx.constraintlayout.widget.Guideline
        android:id="@+id/glTop"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_percent="0.7" />

    <androidx.constraintlayout.widget.Guideline
        android:id="@+id/glBottom"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_percent="1.7" />

    <androidx.viewpager2.widget.ViewPager2
        android:id="@+id/viewpager"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:src="@drawable/red"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

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

motion_scene.xml

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

    <Transition
        motion:constraintSetEnd="@+id/end"
        motion:constraintSetStart="@+id/start"
        motion:duration="300"
        motion:motionInterpolator="easeOut">

        <OnSwipe
            motion:dragDirection="dragDown"
            motion:touchAnchorId="@+id/viewpager"
            motion:touchAnchorSide="bottom" />

    </Transition>

<ConstraintSet android:id="@+id/start">


    </ConstraintSet>


    <ConstraintSet
        android:id="@+id/end"
        motion:deriveConstraintsFrom="@id/start">

        <Constraint
            android:id="@id/ivPoster"
            motion:layout_constraintBottom_toBottomOf="@+id/glBottom"
            motion:layout_constraintEnd_toEndOf="parent"
            motion:layout_constraintStart_toStartOf="parent"
            motion:layout_constraintTop_toBottomOf="@+id/glTop" />

    </ConstraintSet>

</MotionScene>

Answer 1

包括你ViewPager进入 NestedScrollView并在 NestedScrollView 上进行 OnSwipe 事件而不是 ViewPager