ScrollView 不会停留在屏幕的某个部分并占据整个屏幕

Question

I am trying to limit my ScrollView to only a certain section of my screen as I am trying to attach a banner ad to the bottom of my screen and I want the banner ad to be static while the rest of the contents to be scroll-able therefore I don't want the banner ad to be affected by the ScrollView. For some reason though only the scroll-able section is visible on my device screen when I run my app, my banner ad does not show up at all. I have tried multiple methods to fix this problem to make it work and yet I still can't figure it out. This is my current activity_main.xml code

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:background="@color/grey"
tools:context=".MainActivity">


<ScrollView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toTopOf="parent">

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <androidx.cardview.widget.CardView
            android:layout_margin="16dp"
            app:cardCornerRadius="8dp"
            app:cardElevation="8dp"
            app:cardBackgroundColor="@color/blue"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">
            <androidx.appcompat.widget.SearchView
                android:id="@+id/search_view"
                app:defaultQueryHint="Search..."
                app:iconifiedByDefault="false"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"/>
        </androidx.cardview.widget.CardView>

        <LinearLayout
            android:layout_margin="16dp"
            android:orientation="vertical"
            android:layout_width="match_parent"
            android:layout_height="match_parent">
            <TextView
                android:id="@+id/textView_a"
                android:textSize="24sp"
                android:text="A"
                android:textColor="@color/blue"
                android:textAlignment="center"
                android:padding="8dp"
                android:textStyle="italic"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"/>
            <androidx.recyclerview.widget.RecyclerView
                android:id="@+id/recycler_phonetics"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"/>
            <TextView
                android:textSize="24sp"
                android:text="B"
                android:textColor="@color/blue"
                android:textAlignment="center"
                android:padding="8dp"
                android:textStyle="italic"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"/>
            <androidx.recyclerview.widget.RecyclerView
                android:id="@+id/recycler_meanings"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
        </LinearLayout>
    </LinearLayout>
</ScrollView>
<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:layout_constraintBottom_toBottomOf="parent">
    <com.google.android.gms.ads.AdView xmlns:ads="http://schemas.android.com/apk/res-auto"
        android:id="@+id/adView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        ads:adSize="BANNER"
        ads:adUnitId="ca-app-pub-3940256099942544/6300978111"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent">
    </com.google.android.gms.ads.AdView>
</LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

Answer 1

First of all, never use RecyclerView inside Scrollview . Instead, use NestedScrollView .

NestedScrollView is just like ScrollView, but it supports acting as both a nested scrolling parent and child on both new and old versions of Android. Nested scrolling is enabled by default.

If you don't want your RecyclerViews too be scrollable in the first place, add your content as child views to a layout view.

Second, for your ScrollView to take up all the remaining space given by the AdView , craft a constraint chain and give the ScrollView a height of 0dp . This means, you need to constrain the bottom of the ScrollView to the top of the AdView and vice versa.

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
 ...>
    <android.support.v4.widget.NestedScrollView 
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:id="@+id/ScrollView"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toTopOf="@id/LinearAdLayout">

        <!--Your content here-->

    </android.support.v4.widget.NestedScrollView>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/LinearAdLayout"
        app:layout_constraintTop_toBottomOf="@id/ScrollView"
        app:layout_constraintBottom_toBottomOf="parent">
        
        <!--Your AdView here-->

    </LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>