android -------- ConstraintLayout 宽高比和偏移量比（三）

时间 2019-11-10 标签 android constraintlayout 偏移量比

前面的html

ConstraintLayout 介绍（一）android

ConstraintLayout 约束属性（二）app

此博文主要讲解：ide

app:layout_constraintHorizontal_bias
app:layout_constraintDimensionRatio布局

1：app:layout_constraintDimensionRatio（宽高比/百分比布局）google

这个属性感受很是实用，按照比例来分配布局spa

案例：.net

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


    <!--
    layout_constraintDimensionRatio（宽高比）
    若是想实现一个固定宽高比的顶部标题栏的话，能够将宽和高设置为 0dp，
    而后为其设置 app:layout_constraintDimensionRatio 属性，设定宽高比为16：7-->
    <TextView
        android:id="@+id/tv1"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:background="@color/colorAccent"
        app:layout_constraintDimensionRatio="h,16:8"
        android:gravity="center"
        android:text="@string/app_name"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        />

    <!--底部  app:layout_constraintDimensionRatio="w,1:3"-->
    <TextView
        android:id="@+id/tv2"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:background="@color/colorPrimary"
        app:layout_constraintDimensionRatio="w,1:3"
        android:gravity="center"
        android:text="stringapp_name"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        />


    <!--剩余布局居中-->
    <TextView
        android:layout_width="100dp"
        android:layout_height="0dp"
        android:gravity="center"
        android:text="@string/app_name"
        android:background="#ff0000"
        app:layout_constraintDimensionRatio="w,15:25"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/tv1"
        app:layout_constraintBottom_toTopOf="@+id/tv2"
        />

</android.support.constraint.ConstraintLayout>

app:layout_constraintDimensionRatio="h,16:8"  按照宽高的比例，也能够

app:layout_constraintDimensionRatio="w,1:3"   按照高宽的比例

效果图：

2：app:layout_constraintHorizontal_bias（偏移量比）

链条分为水平链条和竖直链条两种，分别用 layout_constraintHorizontal_chainStyle 和 layout_constraintVertical_chainStyle 两个属性来设置
属性值有如下三种：3d

spread
spread_inside
packed

默认值为 spreadcode

能够经过下图来理解各个参数值的含义

举例（水平的）

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


    <!--
    layout_constraintHorizontal_chainStyle
    app:layout_constraintHorizontal_bias（偏移量比）等
    -->

    <!--

         https://www.jianshu.com/p/b884b8c46584
        spread:中间居中，且包含一段空格,平均间隔，4个空格
        packed:中间居中，所有挨在一块儿
        spread_inside: 左右贴边缘，中间居中，中间两个平分间隔
        -->


    <TextView
        android:id="@+id/tv1"
        android:layout_width="wrap_content"
        android:layout_height="50dp"
        android:background="#f5ec7e"
        android:text="Hello World!"
        android:gravity="center"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintHorizontal_chainStyle="spread_inside"
        app:layout_constraintHorizontal_weight="2"
        app:layout_constraintRight_toLeftOf="@+id/tv2"
        />

    <TextView
        android:id="@+id/tv2"
        android:layout_width="wrap_content"
        android:layout_height="50dp"
        android:background="#55e4f4"
        android:gravity="center"
        android:text="Hello World!"
        app:layout_constraintHorizontal_chainStyle="spread_inside"
        app:layout_constraintHorizontal_weight="1"
        app:layout_constraintLeft_toRightOf="@+id/tv1"
        app:layout_constraintRight_toLeftOf="@+id/tv3"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/tv3"
        android:layout_width="wrap_content"
        android:layout_height="50dp"
        android:background="#f186ad"
        android:gravity="center"
        android:text="Hello World!"
        app:layout_constraintHorizontal_chainStyle="spread_inside"
        app:layout_constraintHorizontal_weight="1"
        app:layout_constraintLeft_toRightOf="@+id/tv2"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />





    <!--layout_constraintHorizontal_bias  不设置就居中
        设置了则向水平偏移
        app:layout_constraintVertical_bias="0.5" 垂直中间
    -->
    <TextView
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:text="@string/app_name"
        android:background="@color/colorAccent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintHorizontal_bias="0.2"
        android:gravity="center"
        />

</android.support.constraint.ConstraintLayout>

效果图：

垂直的：

<?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">

    <!--垂直的比例布局 layout_constraintVertical_chainStyle-->

    <TextView
        android:id="@+id/tv1"
        android:layout_width="100dp"
        android:layout_height="0dp"
        android:background="#f5ec7e"
        android:gravity="center"
        android:text="@string/app_name"
        app:layout_constraintBottom_toTopOf="@+id/tv2"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_chainStyle="spread_inside"
        app:layout_constraintVertical_weight="2" />

    <TextView
        android:id="@+id/tv2"
        android:layout_width="100dp"
        android:layout_height="0dp"
        android:background="#55e4f4"
        android:gravity="center"
        android:text="Hello World!"
        app:layout_constraintBottom_toTopOf="@+id/tv3"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/tv1"
        app:layout_constraintVertical_chainStyle="spread_inside"
        app:layout_constraintVertical_weight="1" />

    <TextView
        android:id="@+id/tv3"
        android:layout_width="100dp"
        android:layout_height="0dp"
        android:background="#f186ad"
        android:gravity="center"
        android:text="Hello World!"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/tv2"
        app:layout_constraintVertical_chainStyle="spread_inside"
        app:layout_constraintVertical_weight="1" />


</android.support.constraint.ConstraintLayout>

效果图：

参考文档：

https://developer.android.google.cn/reference/android/support/constraint/ConstraintLayout#Chains

https://constraintlayout.com/basics/create_chains.html

https://www.jianshu.com/p/b884b8c46584