Auto-fit items in Linear layout

Question

I have two constraint layouts in a linear layout. I want the constraint layouts to occupy 30% and 70% of the screen respectively on all devices. What attribute inside the Linear Layout do I need to set in order to achieve this?

Answer 1

This should give the desired result. Setting a weightSum attribute to the parent linear layout and then accordingly giving the weights helps

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:weightSum="1" >

        <android.support.constraint.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="0.3"/>

        <android.support.constraint.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="0.7"/>
</LinearLayout>