提高性能的控件ConstaintLayout

app:layout_constraintLeft_toRightOf="@id/viewB"
当前控件的左侧 在谁(viewB)的右侧

// app:layout_constraintDimensionRatio定义比例
<TextView
       android:id="@+id/tv_bann"
       android:layout_width="0dp"
       android:layout_height="0dp"
       android:background="#765"
       android:gravity="center"
       android:text="Banner"
       app:layout_constraintDimensionRatio="16:6"
       app:layout_constraintRight_toRightOf="parent"
       app:layout_constraintLeft_toLeftOf="parent"
       app:layout_constraintTop_toTopOf="parent" />

//属性有 spread   packed   spread_inside;  layout_width非0
 android:layout_width="wrap_content"
 app:layout_constraintHorizontal_chainStyle="packed"

//用来设定权重
app:layout_constraintHorizontal_weight="1"

constraint_pic.png

<?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/tv_bann"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:background="#765"
        android:gravity="center"
        android:text="Banner"
        app:layout_constraintDimensionRatio="h,16:6"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/tv1"
        android:layout_width="140dp"
        android:layout_height="86dp"
        android:layout_margin="12dp"
        android:background="#fd3"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toBottomOf="@id/tv_bann" />

    <TextView
        android:id="@+id/tv_tv2"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginLeft="12dp"
        android:layout_marginRight="16dp"
        android:layout_marginTop="12dp"
        android:text="马云:一年交税170多亿马云:一年交税170多亿马云:一年交税170多亿马云:一年交税170多亿马云:一年交税170多亿"
        app:layout_constraintLeft_toRightOf="@id/tv1"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@id/tv_bann" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="12dp"
        android:layout_marginTop="8dp"
        android:text="五分钟"
        android:textColor="#333"
        app:layout_constraintLeft_toRightOf="@id/tv1"
        app:layout_constraintTop_toBottomOf="@id/tv_tv2" />


    <Button
        android:id="@+id/btn1"
        android:layout_width="100dp"
        android:layout_height="wrap_content"
        android:text="btn1"
        app:layout_constraintTop_toBottomOf="@id/tv1" />

    <Button
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="btn1"
        app:layout_constraintLeft_toRightOf="@id/btn1"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@id/tv1" />

    <TextView
        android:id="@+id/tab1"
        android:layout_width="0dp"
        android:layout_height="40dp"
        android:background="#f67"
        android:gravity="center"
        android:text="tab1"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintHorizontal_weight="1"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toLeftOf="@id/tab2" />

    <TextView
        android:id="@+id/tab2"
        android:layout_width="0dp"
        android:layout_height="40dp"
        android:background="#A67"
        android:gravity="center"
        android:text="tab2"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintHorizontal_weight="1"
        app:layout_constraintLeft_toRightOf="@id/tab1"
        app:layout_constraintRight_toLeftOf="@id/tab3" />

    <TextView
        android:id="@+id/tab3"
        android:layout_width="0dp"
        android:layout_height="40dp"
        android:background="#767"
        android:gravity="center"
        android:text="tab3"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintHorizontal_weight="1"
        app:layout_constraintLeft_toRightOf="@id/tab2"
        app:layout_constraintRight_toRightOf="parent" />

    <android.support.constraint.Guideline
        android:id="@+id/guideline_h"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_percent="0.8" />

    <android.support.constraint.Guideline
        android:id="@+id/guideline_w"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        app:layout_constraintGuide_percent="0.1" />

    <TextView
        android:layout_width="60dp"
        android:layout_height="60dp"
        android:background="@color/colorAccent"
        android:gravity="center"
        android:text="Guideline"
        android:textColor="#FFF"
        app:layout_constraintLeft_toRightOf="@id/guideline_w"
        app:layout_constraintTop_toBottomOf="@id/guideline_h" />

    <TextView
        android:layout_width="60dp"
        android:layout_height="60dp"
        android:background="@color/colorPrimaryDark"
        android:gravity="center"
        android:text="新增"
        android:textColor="#FFF"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintHorizontal_bias="0.9"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.9" />
</android.support.constraint.ConstraintLayout>