如果高度小于Android中的屏幕，如何垂直扩展ScrollView？ （xml /以编程方式）

Question

I'm new to Android and I need to use a ScrollView to wrap my whole content, since in some cases it needs to take up more height than is available on the screen . Most of the cases though, the height of the content is smaller than the screen . The ScrollView will almost always have a background color (not white), which needs to fill the whole screen available, not just wrap the content. I've checked a few other topics related to this, but the answers were outdated and none of them seems to solve the issue or even focuses on the question asked.

Extra details: Inside the ScrollView there is a RelativeLayout which encapsulates the content, as there can be only one element inside a ScrollView.

Please limit the answers to Java for Android Studio or XML configuration, if they don't use a programmatic approach, neither Kotlin, nor any other language used for Android programming. Thank you in advance!

<?xml version="1.0" encoding="utf-8"?>

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:id="@+id/detailed_scroll_view"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:fillViewport="true">

  <RelativeLayout
    android:id="@+id/detailed_view_container"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <androidx.constraintlayout.widget.ConstraintLayout
      android:layout_width="wrap_content"
      android:layout_height="wrap_content">

      <ImageView
        android:id="@+id/product_image"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:adjustViewBounds="true"
        android:contentDescription="@string/product_image"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

      <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/details_container"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@drawable/details_container_background"
        android:clipChildren="false"
        android:clipToPadding="false"
        android:elevation="10dp"
        android:translationY="-50dp"
        android:visibility="invisible"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/product_image">

        <TextView
          android:id="@+id/product_name"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:paddingBottom="20dp"
          android:textSize="25sp"
          app:layout_constraintEnd_toEndOf="parent"
          app:layout_constraintStart_toStartOf="parent"
          app:layout_constraintTop_toTopOf="parent" />

        <TextView
          android:id="@+id/description"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          app:layout_constraintEnd_toEndOf="parent"
          app:layout_constraintStart_toStartOf="parent"
          app:layout_constraintTop_toBottomOf="@+id/product_name" />

      </androidx.constraintlayout.widget.ConstraintLayout>

      <GridLayout
        android:id="@+id/params_container"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_constraintTop_toBottomOf="@id/details_container"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent">

        <View
          android:id="@+id/param_calories"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:adjustViewBounds="true"
          android:background="@drawable/param_with_icon"
          app:layout_constraintStart_toStartOf="parent"
          app:layout_constraintTop_toTopOf="parent" />

      </GridLayout>

    </androidx.constraintlayout.widget.ConstraintLayout>


    <com.google.android.material.progressindicator.CircularProgressIndicator
      android:id="@+id/spinner"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_centerInParent="true"
      android:layout_centerHorizontal="true"
      android:layout_centerVertical="true"
      android:indeterminate="true"
      app:indicatorColor="@android:color/background_dark"
      app:layout_constraintBottom_toBottomOf="parent"
      app:layout_constraintEnd_toEndOf="parent"
      app:layout_constraintStart_toStartOf="parent"
      app:layout_constraintTop_toTopOf="parent" />

  </RelativeLayout>

</ScrollView>

Answer 1

Simply put your ScrollView inside a ConstraintLayout , and set ScrollView 's android:layout_height="0dp" like following:

<?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">

    <ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/detailed_scroll_view"
        android:layout_height="0dp"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        android:fillViewport="true">

        ...
        
    </ScrollView>

</androidx.constraintlayout.widget.ConstraintLayout>

Answer 2

Your problem is really about how you set the widths and heights.

• MATCH_PARENT - As big as parent's container.
• WRAP_CONTENT - As big as child's container or default width/height.

<!-- As big as specified container or device screen if it has no container -->
<ScrollView
    ...
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    ...
    >

    <!-- As big as the ScrollView -->
    <RelativeLayout
        android:id="@+id/detailed_view_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent">