我正在尝试开发一个视图，用户在滚动回收器视图时头视图会上升。但是，如果我将RecyclerView放在NestedScrollView内，那么使用xml我就无法滚动。我已设置.setNestedScrollingEnabled(false);。
<android.support.constraint.ConstraintLayout 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:id="@+id/secondviewLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/white"
android:clipToPadding="true"
android:fillViewport="true"
tools:context="com.futuromolise.com.futuromolise.SecondViewController">
<android.support.constraint.ConstraintLayout
android:id="@+id/category_list_view"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="1.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0">
<Button
android:id="@+id/search_button"
android:layout_width="20dp"
android:layout_height="20dp"
android:layout_marginEnd="8dp"
android:layout_marginTop="8dp"
android:background="@drawable/search_icon"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="1.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<android.support.v7.widget.RecyclerView
android:id="@+id/categories_news_recycler"
android:layout_width="0dp"
android:layout_height="40dp"
android:layout_marginEnd="8dp"
android:padding="0dp"
app:layout_constraintEnd_toStartOf="@+id/search_button"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
<android.support.v4.widget.NestedScrollView
android:id="@+id/n_scroll"
android:layout_width="0dp"
android:layout_height="0dp"
android:fillViewport="true"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/category_list_view">
<android.support.constraint.ConstraintLayout
android:id="@+id/parallax_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/category_list_view">
<android.support.constraint.ConstraintLayout
android:id="@+id/news_first_view_header"
android:layout_width="match_parent"
android:layout_height="310dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<ImageView
android:id="@+id/first_news_imageView"
android:layout_width="0dp"
android:layout_height="0dp"
android:scaleType="centerCrop"
android:src="@drawable/molise2"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/first_new_title"
style="@style/TextShadow"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginBottom="50dp"
android:layout_marginEnd="16dp"
android:layout_marginStart="16dp"
android:layout_marginTop="100dp"
android:ellipsize="end"
android:fontFamily="@font/radomirextrabold"
android:maxLines="4"
android:text="n short, the views are not built yet in onCreate(), onStart(), or onResume(). Since they technically don't exist (as far as the ViewGroup is concerned), their dimensions are 0."
android:textAllCaps="false"
android:textColor="@color/white"
android:textSize="32sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<com.veinhorn.tagview.TagView
android:id="@+id/first_new_category"
style="@style/TextShadow"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="8dp"
android:layout_marginEnd="104dp"
android:layout_marginStart="16dp"
android:fontFamily="@font/radomirextrabold"
android:paddingBottom="0dp"
android:paddingLeft="10dp"
android:paddingRight="10dp"
android:paddingTop="0dp"
android:text="@string/placeholder"
android:textSize="15sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="@+id/first_new_time"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintVertical_bias="0.538"
app:tagBorderRadius="50"
app:tagColor="@color/colorPrimaryDark"
app:tagType="classic" />
<com.veinhorn.tagview.TagView
android:id="@+id/first_new_time"
style="@style/TextShadow"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="8dp"
android:layout_marginEnd="16dp"
android:layout_marginTop="8dp"
android:fontFamily="@font/radomirlight"
android:paddingBottom="0dp"
android:paddingLeft="10dp"
android:paddingRight="10dp"
android:paddingTop="0dp"
android:text="@string/placeholder"
android:textSize="12sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintVertical_bias="0.54"
app:tagBorderRadius="50"
app:tagColor="?attr/colorControlNormal"
app:tagType="classic" />
</android.support.constraint.ConstraintLayout>
<android.support.v7.widget.RecyclerView
android:id="@+id/newsgrid_recyclerView"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/news_first_view_header" />
</android.support.constraint.ConstraintLayout>
</android.support.v4.widget.NestedScrollView>
</android.support.constraint.ConstraintLayout>