MotionLayout + RecyclerView 需要做一些額外的處理才能有類似嵌套滑動(dòng)的聯(lián)動(dòng)效果。

start_layout

<androidx.constraintlayout.motion.widget.MotionLayout
        android:id="@+id/coordinatorLayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layoutDescription="@xml/activity_main_scene">


        <TextView
            android:id="@+id/textView2"
            android:layout_width="50dp"
            android:layout_height="50dp"
            android:background="#999"
            android:gravity="center"
            android:text="返回"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintVertical_bias="0" />

        <TextView
            android:id="@+id/tvTitle"
            android:layout_width="100dp"
            android:layout_height="50dp"
            android:background="#999"
            android:gravity="center"
            android:text="標(biāo)題"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.5"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintVertical_bias="0" />

        <TextView
            android:id="@+id/tvSearch"
            android:layout_width="0dp"
            android:layout_height="50dp"
            android:background="#666"
            android:gravity="center_vertical"
            android:hint="搜索"
            android:paddingStart="15dp"
            android:paddingEnd="15dp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@id/tvTitle"
            app:layout_constraintVertical_bias="0" />

        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/rv"
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:orientation="vertical"
            app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@id/tvSearch" />
    </androidx.constraintlayout.motion.widget.MotionLayout>

scene

<?xml version="1.0" encoding="utf-8"?>
<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="10000">
       <KeyFrameSet>
       </KeyFrameSet>
        <OnSwipe motion:nestedScrollFlags="supportScrollUp" motion:autoCompleteMode="continuousVelocity" motion:dragDirection="dragUp"
            motion:touchAnchorId="@id/rv"http://劃重點(diǎn)
            />
    </Transition>

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

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

        <Constraint
            android:id="@+id/tvTitle"
            motion:layout_constraintEnd_toEndOf="parent"
            android:layout_width="100dp"
            android:layout_height="0dp"
            motion:layout_constraintBottom_toBottomOf="parent"
            motion:layout_constraintVertical_bias="0"
            motion:layout_constraintHorizontal_bias="0.5"
            motion:layout_constraintTop_toTopOf="parent"
            motion:layout_constraintStart_toStartOf="parent"
            android:visibility="gone" />
        <Constraint
            android:id="@+id/tvSearch"
            motion:layout_constraintEnd_toEndOf="parent"
            android:layout_width="0dp"
            android:layout_height="50dp"
            motion:layout_constraintBottom_toBottomOf="parent"
            motion:layout_constraintVertical_bias="0"
            motion:layout_constraintTop_toBottomOf="@id/tvTitle"
            motion:layout_constraintStart_toStartOf="parent"
            android:layout_marginStart="50dp" />
        <Constraint
            motion:layout_constraintEnd_toEndOf="parent"
            android:layout_width="0dp"
            android:layout_height="0dp"
            motion:layout_constraintBottom_toBottomOf="parent"
            motion:layout_constraintTop_toBottomOf="@id/tvSearch"
            motion:layout_constraintStart_toStartOf="parent"
            android:id="@+id/rv"
            android:layout_marginStart="50dp"
            android:layout_marginEnd="50dp" />


    </ConstraintSet>
</MotionScene>

代碼處理：
binding.rv.addOnScrollListener(object : RecyclerView.OnScrollListener() {

            override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
                if(dy>0){
                    if( binding.motionLayout.currentState== binding.motionLayout.startState){
                        binding.motionLayout.transitionToEnd()
                    }
                }else{
                    if( binding.motionLayout.currentState== binding.motionLayout.endState) {
                        binding.motionLayout.transitionToStart()
                    }
                }
            }
        })