为什么我的 ConstraintLayout 中的 ScrollView 一直没有高度而不是遵循约束？

Question

我的 ScrollView 在片段中没有高度时遇到问题。我正在向嵌套在我的 ScrollView 中的 LinearLayout 添加视图。如果我将 ScrollView 的高度设置为 0dp，那么我在 LinearLayout 中看不到视图。如果我将 ScrollView 的高度设置为 410dp，那么我会看到视图。我只是想填满屏幕的底部。

我错过了什么？

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <TextView
        android:id="@+id/seriesTitleTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:labelFor="@+id/seriesTitleEditBox"
        android:text="Series Title"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

    <EditText
        android:id="@+id/seriesTitleEditBox"
        android:layout_width="390dp"
        android:layout_height="40dp"
        android:imeOptions="actionNext"
        android:inputType="textCapWords"
        android:selectAllOnFocus="true"
        app:layout_constraintLeft_toLeftOf="@+id/seriesTitleTextView"
        app:layout_constraintTop_toBottomOf="@+id/seriesTitleTextView"
        />

    <TextView
        android:id="@+id/tvmdIDTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:labelFor="@+id/tvmdIDEditBox"
        android:text="TVMD ID"
        app:layout_constraintLeft_toLeftOf="@+id/seriesTitleEditBox"
        app:layout_constraintTop_toBottomOf="@+id/seriesTitleEditBox"
        />

    <EditText
        android:id="@+id/tvmdIDEditBox"
        android:layout_width="200dp"
        android:layout_height="40dp"
        android:imeOptions="actionNext"
        android:inputType="textCapWords"
        android:selectAllOnFocus="true"
        app:layout_constraintLeft_toLeftOf="@+id/tvmdIDTextView"
        app:layout_constraintTop_toBottomOf="@+id/tvmdIDTextView"
        />

    <Switch
        android:id="@+id/finishedSwitch"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintTop_toBottomOf="@id/tvmdIDTextView"
        app:layout_constraintRight_toRightOf="parent"
        android:text="Finished? "/>

    <TextView
        android:id="@+id/detailsHeaderBackgroundTextView"
        android:text=" "
        android:layout_width="0dp"
        android:layout_height="50dp"
        android:layout_marginTop="20dp"
        android:background="@color/colorPrimary"
        app:layout_constraintTop_toBottomOf="@+id/finishedSwitch"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        />

    <TextView
        android:id="@+id/detailHeaderTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="20dp"
        android:layout_marginTop="10dp"
        android:background="@color/colorPrimary"
        android:text="Season 99"
        android:textColor="@android:color/white"
        android:textSize="20sp"
        app:layout_constraintLeft_toLeftOf="@+id/detailsHeaderBackgroundTextView"
        app:layout_constraintTop_toTopOf="@id/detailsHeaderBackgroundTextView"
        />

    <ImageButton
        android:id="@+id/addViewing"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:background="@color/colorPrimary"
        android:contentDescription="Add Button"
        android:onClick="addViewingClickHandler"
        android:src="@android:drawable/ic_menu_add"
        app:layout_constraintRight_toRightOf="@id/detailsHeaderBackgroundTextView"
        app:layout_constraintTop_toTopOf="@id/detailsHeaderBackgroundTextView"/>

    <ScrollView
        android:layout_width="wrap_content"
        android:layout_height="0dp"
        app:layout_constraintTop_toBottomOf="@+id/detailsHeaderBackgroundTextView"
        app:layout_constraintBottom_toBottomOf="parent"
        >

        <LinearLayout
            android:id="@+id/detailsLayout"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical"
            />

    </ScrollView>

</android.support.constraint.ConstraintLayout>

Answer 1

只需将滚动视图更改为如下所示

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

<TextView
    android:id="@+id/seriesTitleTextView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginTop="8dp"
    android:labelFor="@+id/seriesTitleEditBox"
    android:text="Series Title"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

<EditText
    android:id="@+id/seriesTitleEditBox"
    android:layout_width="390dp"
    android:layout_height="40dp"
    android:imeOptions="actionNext"
    android:inputType="textCapWords"
    android:selectAllOnFocus="true"
    app:layout_constraintLeft_toLeftOf="@+id/seriesTitleTextView"
    app:layout_constraintTop_toBottomOf="@+id/seriesTitleTextView" />

<TextView
    android:id="@+id/tvmdIDTextView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginTop="8dp"
    android:labelFor="@+id/tvmdIDEditBox"
    android:text="TVMD ID"
    app:layout_constraintLeft_toLeftOf="@+id/seriesTitleEditBox"
    app:layout_constraintTop_toBottomOf="@+id/seriesTitleEditBox" />

<EditText
    android:id="@+id/tvmdIDEditBox"
    android:layout_width="200dp"
    android:layout_height="40dp"
    android:imeOptions="actionNext"
    android:inputType="textCapWords"
    android:selectAllOnFocus="true"
    app:layout_constraintLeft_toLeftOf="@+id/tvmdIDTextView"
    app:layout_constraintTop_toBottomOf="@+id/tvmdIDTextView" />

<Switch
    android:id="@+id/finishedSwitch"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Finished? "
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toBottomOf="@id/tvmdIDTextView" />

<TextView
    android:id="@+id/detailsHeaderBackgroundTextView"
    android:layout_width="0dp"
    android:layout_height="50dp"
    android:layout_marginTop="20dp"
    android:background="@color/colorPrimary"
    android:text=" "
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/finishedSwitch" />

<TextView
    android:id="@+id/detailHeaderTextView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginStart="20dp"
    android:layout_marginTop="10dp"
    android:background="@color/colorPrimary"
    android:text="Season 99"
    android:textColor="@android:color/white"
    android:textSize="20sp"
    app:layout_constraintLeft_toLeftOf="@+id/detailsHeaderBackgroundTextView"
    app:layout_constraintTop_toTopOf="@id/detailsHeaderBackgroundTextView" />

<ImageButton
    android:id="@+id/addViewing"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginTop="8dp"
    android:background="@color/colorPrimary"
    android:contentDescription="Add Button"
    android:onClick="addViewingClickHandler"
    android:src="@android:drawable/ic_menu_add"
    app:layout_constraintRight_toRightOf="@id/detailsHeaderBackgroundTextView"
    app:layout_constraintTop_toTopOf="@id/detailsHeaderBackgroundTextView" />

<ScrollView
    android:layout_width="0dp"
    android:layout_height="0dp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/detailsHeaderBackgroundTextView">

    <LinearLayout
        android:id="@+id/detailsLayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <!--SAMPLE TEXTVIEW-->
        <android.support.v7.widget.AppCompatTextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="hello" />

    </LinearLayout>

</ScrollView>

</android.support.constraint.ConstraintLayout>

Answer 2

问题出在将高度设置为 wrap_content 而不是 match_parent 的父布局。

为什么我的 ConstraintLayout 中的 ScrollView 一直没有高度而不是遵循约束？

Why does my ScrollView in my ConstraintLayout keep having no height instead of following the constraints?

android

scrollview

android-fragments

android-constraintlayout