我的屏幕由一个ConstraintLayout和两个孩子组成。一个孩子是一个RecyclerView,它占据了整个屏幕。另一个孩子是另一个ConstraintLayout,它包含一个TextView(屏幕实际上比这更复杂,但是我将其缩小为此处的内容以便于理解)。子ConstraintLayout放置在RecyclerView上方,并在您滚动RecyclerView时向上滚动。这是通过在RecyclerView上使用滚动侦听器并重新调整子ConstraintLayout的Y位置来完成的。子ConstraintLayout必须是可点击的。
我遇到的问题是,如果您尝试通过先按下子ConstraintLayout来滚动RecyclerView,则滚动将无法进行。但是,子ConstraintLayout的click事件处理程序将起作用。
根据我对Android如何处理触摸事件的理解,如果视图在其onTouchEvent处理函数中返回false,则该视图将不会收到任何其他运动事件的通知。因此,从理论上讲,如果我的子ConstraintLayout在其onTouchEvent处理函数中返回false,则RecyclerView仍应获取滚动运动事件。
这是我的布局xml:
<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:background="#55338855">
<androidx.constraintlayout.motion.widget.MotionLayout
android:id="@+id/dashboardConstraintLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
app:layoutDescription="@xml/dashboard_initial_animation_start"
app:showPaths="false">
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/contentRecyclerView"
android:layout_width="0dp"
android:layout_height="0dp"
android:clipChildren="false"
android:fitsSystemWindows="true"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toEndOf="@id/guideWelcome"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintWidth_default="percent"
app:layout_constraintWidth_percent="1.0" />
<ReservationCard
android:id="@+id/reservationConstraintLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginTop="60dp"
android:layout_marginEnd="16dp"
android:layout_marginBottom="16dp"
android:background="@color/dashboard_reservation_card_background_color"
android:padding="16dp"
android:visibility="invisible"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/txtSearch">
<TextView
android:id="@+id/txtReservationHeader"
style="@style/Apptheme.Label"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="@string/dashboard_screen_reservation_card_headline"
android:textColor="@color/dashboard_reservation_card_text_color" />
</com.sinnerschrader.motelone.screens.dashboard.ReservationCard>
</androidx.constraintlayout.motion.widget.MotionLayout>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
这是我自定义的ConstraintLayout(ReservationCard):
class ReservationCard : androidx.constraintlayout.widget.ConstraintLayout {
constructor(context: Context?) : super(context)
constructor(context: Context?,attrs: AttributeSet?) : super(context,attrs)
constructor(context: Context?,attrs: AttributeSet?,defStyleAttr: Int) : super(context,attrs,defStyleAttr)
private val gestureDetector: GestureDetector
init {
gestureDetector = GestureDetector(GestureListener())
}
override fun onTouchEvent(ev: MotionEvent?): Boolean {
if (ev?.action == MotionEvent.actION_DOWN) {
gestureDetector.onTouchEvent(ev)
return true
} else if (ev?.action == MotionEvent.actION_UP) {
gestureDetector.onTouchEvent(ev)
return false
} else {
super.onTouchEvent(ev)
return false
}
}
private inner class GestureListener : GestureDetector.OnGestureListener {
override fun onfling(p0: MotionEvent?,p1: MotionEvent?,p2: Float,p3: Float): Boolean {
return false
}
override fun onScroll(p0: MotionEvent?,p3: Float): Boolean {
return false
}
override fun onLongPress(p0: MotionEvent?) {
}
override fun onDown(p0: MotionEvent?): Boolean {
return false
}
override fun onShowPress(p0: MotionEvent?) {
}
override fun onSingletapUp(p0: MotionEvent?): Boolean {
return false
}
}
}