Android Align LinearLayout at Bottom not Working

Question

I have this LinearLayout and in it is a Map Fragment and this all works but I cannot get the linear layout to align to the bottom of the screen for some reason. Here is my xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity"
    android:baselineAligned="false"
    android:weightSum="1"
    android:background="@mipmap/background_colour">

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="30dp"
        android:layout_height="31dp"
        android:weightSum="1"
        android:id="@+id/back_button"
        android:background="@drawable/navigation_back"
        android:layout_marginTop="20dp"
        android:layout_marginLeft="10dp">

    </LinearLayout>

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="0.31">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:text="Large Text"
            android:id="@+id/textView7" />
    </LinearLayout>

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="0.30">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:text="Large Text"
            android:id="@+id/textView6" />
    </LinearLayout>

    <LinearLayout
        android:id="@+id/lay"
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_alignParentBottom="true"
        android:layout_height="wrap_content"
        android:layout_weight="3.5">



    </LinearLayout>
    </LinearLayout>

The LinearLayout I am trying to align is the id: "lay" one.

Answer 1

I found a fix:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity"
    android:baselineAligned="false"
    android:weightSum="1"
    android:background="@mipmap/background_colour">

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="30dp"
        android:layout_height="31dp"
        android:weightSum="1"
        android:id="@+id/back_button"
        android:background="@drawable/navigation_back"
        android:layout_marginTop="20dp"
        android:layout_marginLeft="10dp">

    </LinearLayout>

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="177dp">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:text="Large Text"
            android:id="@+id/textView7" />
    </LinearLayout>

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="146dp">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:text="Large Text"
            android:id="@+id/textView6" />
    </LinearLayout>

    <LinearLayout
        android:id="@+id/lay"
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_alignParentBottom="true"
        android:layout_height="match_parent">



</LinearLayout>
</LinearLayout>