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

Z时代
2024-01-10
分类：问答

我有我的ScrollView在我的片段没有高度的问题。我将视图添加到嵌套在我的ScrollView中的LinearLayout中。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。为什么我的ConstraintLayout中的ScrollView保持没有高度而不是遵循约束？

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>

回答：

问题从具有高度设置为WRAP_CONTENT父布局来了，而不是match_parent。

回答：

只要改变你的滚动视图喜欢下面

<?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>