java - 在 ConstraintLayout 中的 View 的所有方向上应用约束是最佳实践吗？

Question

我有一个显示为以下蓝图的 ConstraintLayout:

我意识到并不是所有的 View 对象在所有方向上都有约束。例如，正如您将看到的，RecyclerView 在顶部没有约束。我的一些 TextView 对象也没有顶部和底部约束。

尝试在多台设备上扩展时，这会带来什么风险？有推荐的最佳实践吗？例如，现在，我担心 RecyclerView 的顶部在没有约束的情况下可能会在更大的设备上“拉伸(stretch)”。以下是 XML:

<?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"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:id="@+id/imageView2"
        android:layout_width="113dp"
        android:layout_height="119dp"
        android:layout_marginBottom="31dp"
        android:layout_marginEnd="110dp"
        android:layout_marginLeft="110dp"
        android:layout_marginRight="110dp"
        android:layout_marginStart="110dp"
        android:layout_marginTop="16dp"
        app:layout_constraintBottom_toTopOf="@+id/textView2"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="0dp"
        android:layout_height="36dp"
        android:gravity="center"
        android:text="Polls Created"
        app:layout_constraintEnd_toStartOf="@+id/textView"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintHorizontal_weight=".33"
        app:layout_constraintStart_toStartOf="parent"
        tools:layout_editor_absoluteY="167dp" />

    <TextView
        android:id="@+id/textView3"
        android:layout_width="0dp"
        android:layout_height="36dp"
        android:gravity="center"
        android:text="Votes Given"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintHorizontal_weight=".33"
        app:layout_constraintStart_toEndOf="@+id/textView"
        tools:layout_editor_absoluteY="167dp" />


    <TextView
        android:id="@+id/textView"
        android:layout_width="0dp"
        android:layout_height="36dp"
        android:layout_marginTop="31dp"
        android:gravity="center"
        android:text="Votes Received"
        app:layout_constraintEnd_toStartOf="@+id/textView3"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintHorizontal_weight=".33"
        app:layout_constraintStart_toEndOf="@+id/textView2"
        app:layout_constraintTop_toBottomOf="@+id/imageView2" />

    <TextView
        android:gravity="center"
        android:id="@+id/textView5"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="1"
        app:layout_constraintEnd_toStartOf="@+id/textView4"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintHorizontal_weight=".33"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView2" />

    <TextView
        android:gravity="center"
        android:id="@+id/textView4"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        app:layout_constraintEnd_toStartOf="@+id/textView6"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintHorizontal_weight=".33"
        app:layout_constraintStart_toEndOf="@+id/textView5"
        app:layout_constraintTop_toBottomOf="@+id/textView" />

    <TextView
        android:gravity="center"
        android:id="@+id/textView6"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="3"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintHorizontal_weight=".33"
        app:layout_constraintStart_toEndOf="@+id/textView4"
        app:layout_constraintTop_toBottomOf="@+id/textView3" />


    <TextView
        android:id="@+id/textView7"
        android:layout_width="287dp"
        android:layout_height="36dp"
        android:layout_marginBottom="30dp"
        android:layout_marginEnd="48dp"
        android:layout_marginLeft="49dp"
        android:layout_marginRight="48dp"
        android:layout_marginStart="49dp"
        android:layout_marginTop="19dp"
        android:gravity="center_horizontal"
        android:text="USER X Recent polls"
        app:layout_constraintBottom_toTopOf="@+id/recyclerView"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView5" />

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="match_parent"
        android:layout_height="260dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"></android.support.v7.widget.RecyclerView>

</android.support.constraint.ConstraintLayout>

Answer 1

这是我的习惯。正确使用百分比尺寸和指南，以免直接放置边距。但是，有必要计算百分比以使小部件不重叠。

<?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">

    <android.support.constraint.Guideline
        android:id="@+id/topGl"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_percent=".05" />

    <android.support.constraint.Guideline
        android:id="@+id/textViewTopGl"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_percent=".35" />

    <ImageView
        android:id="@+id/imageView2"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toTopOf="@+id/textView2"
        app:layout_constraintDimensionRatio="w,1:1"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="@id/topGl"
        app:layout_constraintHeight_percent=".25" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:gravity="center"
        android:text="Polls Created"
        app:layout_constraintEnd_toStartOf="@+id/textView"
        app:layout_constraintHeight_percent=".05"
        app:layout_constraintHorizontal_chainStyle="packed"
        app:layout_constraintHorizontal_weight="1"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="@id/textViewTopGl" />

    <TextView
        android:id="@+id/textView3"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:gravity="center"
        android:text="Votes Given"
        app:layout_constraintBottom_toBottomOf="@id/textView2"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_weight="1"
        app:layout_constraintStart_toEndOf="@+id/textView"
        app:layout_constraintTop_toTopOf="@id/textView2" />

    <TextView
        android:id="@+id/textView"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:gravity="center"
        android:text="Votes Received"
        app:layout_constraintBottom_toBottomOf="@id/textView2"
        app:layout_constraintEnd_toStartOf="@+id/textView3"
        app:layout_constraintHorizontal_weight="1"
        app:layout_constraintStart_toEndOf="@+id/textView2"
        app:layout_constraintTop_toBottomOf="@+id/imageView2"
        app:layout_constraintTop_toTopOf="@id/textView2" />

    <TextView
        android:id="@+id/textView5"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:gravity="center"
        android:text="1"
        app:layout_constraintEnd_toEndOf="@id/textView2"
        app:layout_constraintHeight_percent=".05"
        app:layout_constraintStart_toStartOf="@id/textView2"
        app:layout_constraintTop_toBottomOf="@id/textView2" />

    <TextView
        android:id="@+id/textView4"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:gravity="center"
        app:layout_constraintBottom_toBottomOf="@id/textView5"
        app:layout_constraintEnd_toEndOf="@id/textView"
        app:layout_constraintStart_toStartOf="@id/textView"
        app:layout_constraintTop_toTopOf="@id/textView5" />

    <TextView
        android:id="@+id/textView6"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:gravity="center"
        android:text="3"
        app:layout_constraintBottom_toBottomOf="@id/textView5"
        app:layout_constraintEnd_toEndOf="@id/textView3"
        app:layout_constraintStart_toStartOf="@id/textView3"
        app:layout_constraintTop_toTopOf="@id/textView5" />

    <TextView
        android:id="@+id/textView7"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:gravity="center"
        android:text="USER X Recent polls"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHeight_percent=".05"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView5" />

    <android.support.constraint.Guideline
        android:id="@+id/recyclerViewTopGl"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_percent=".53" />

    <android.support.v7.widget.RecyclerView
        android:id="@+id/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_toTopOf="@id/recyclerViewTopGl" />

</android.support.constraint.ConstraintLayout>