ConstraintLayout 平分布局

添加依赖

compile 'com.android.support.constraint:constraint-layout:1.0.2'

创建布局

"1.0" encoding="utf-8"?>
"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:orientation="vertical">

    "@+id/bt_a"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="scroller_scroll"
        android:textSize="12dp"
        app:layout_constraintBottom_toTopOf="@+id/button3"
        app:layout_constraintHorizontal_weight="1"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toLeftOf="@+id/bt_b"/>

    "@+id/bt_b"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="scroller_fling"
        android:textSize="12dp"
        app:layout_constraintBottom_toTopOf="@+id/button3"
        app:layout_constraintHorizontal_weight="1"
        app:layout_constraintLeft_toRightOf="@+id/bt_a"
        app:layout_constraintRight_toLeftOf="@+id/bt_c"/>

    "@+id/bt_c"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="over_scroll"
        android:textSize="12dp"
        app:layout_constraintBottom_toTopOf="@+id/button3"
        app:layout_constraintHorizontal_weight="1"
        app:layout_constraintLeft_toRightOf="@+id/bt_b"
        app:layout_constraintRight_toRightOf="@+id/bt_d"/>

    "@+id/bt_d"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="overs_fling"
        android:textSize="12dp"
        app:layout_constraintBottom_toTopOf="@+id/button3"
        app:layout_constraintHorizontal_weight="1"
        app:layout_constraintLeft_toRightOf="@+id/bt_c"
        app:layout_constraintRight_toRightOf="parent"/>

    "@+id/button3"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:text="Button"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        />


复制代码

需要了解的地方

1. 宽度为0dp android:layout_width="0dp"
2. 需要准确指定左右的约束 app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toLeftOf="@+id/bt_b"//使用@id 编译不通过，使用@+id就可以了
3. 指定权重 app:layout_constraintHorizontal_weight="1"
4. 约束也可以为parent app:layout_constraintBottom_toBottomOf="parent"

转载于:https://juejin.im/post/5a31ee3af265da43294e0fe1