Android ConstraintLayout按比例缩放View详解手机开发

Android ConstraintLayout按比例缩放View

关键点有两个，第一，使用Android ConstraintLayout的layout_constraintDimensionRatio属性，设置宽高比缩放比例，宽:高。第二，恒定宽和高，另外一个方向就会按照比例缩放。

    <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/text0" 
            android:layout_width="0dp" 
            android:layout_height="100dp" 
            android:background="@android:color/holo_orange_light" 
            android:gravity="center" 
            android:text="w=0,h=100/n5:2" 
            android:textColor="@android:color/white" 
            android:textSize="10dp" 
            app:layout_constraintDimensionRatio="5:2" 
            app:layout_constraintLeft_toLeftOf="parent" 
            app:layout_constraintTop_toTopOf="parent" /> 
 
        <TextView 
            android:id="@+id/text1" 
            android:layout_width="100dp" 
            android:layout_height="0dp" 
            android:background="@android:color/holo_red_light" 
            android:gravity="center" 
            android:text="w=100,h=0/n5:2" 
            android:textColor="@android:color/white" 
            android:textSize="10dp" 
            app:layout_constraintDimensionRatio="5:2" 
            app:layout_constraintLeft_toLeftOf="parent" 
            app:layout_constraintTop_toBottomOf="@id/text0" /> 
    </android.support.constraint.ConstraintLayout>

运行结果如图：