Android GUI：布局管理器

Question

I'm learning about Layout managers to improve my app design. For the most part it worked out ok. The only thing I want is my buttons to be positioned a little higher.I can achieve this by removing the 3 buttons from the layout manager but by doing this I have issues on lower res devices. (The buttons will position themselves over the EditText fields or position themselves over my ad at the bottom). I've tried some things I found online but I only ended up ruining the layout.

Here is my XML file:

     <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:ads="http://schemas.android.com/apk/res-auto"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <LinearLayout
        android:id="@+id/linearLayout3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <LinearLayout
            android:id="@+id/textviewLayoutLeft"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:orientation="vertical">

            <TextView
                android:id="@+id/tvPpl"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:paddingBottom="10dp"
                android:paddingLeft="10dp"
                android:paddingRight="10dp"
                android:paddingTop="20dp"
                android:text="Price Per Liter"
                android:textStyle="bold" />

            <TextView
                android:id="@+id/tvAvgConsumption"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:paddingBottom="10dp"
                android:paddingLeft="10dp"
                android:paddingRight="10dp"
                android:paddingTop="10dp"
                android:text="avg(l/100km)"
                android:textStyle="bold" />

            <TextView
                android:id="@+id/tvDistance"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:padding="10dp"
                android:text="Distance (km)"
                android:textStyle="bold" />

            <TextView
                android:id="@+id/tvAmountOfPersons"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:paddingBottom="10dp"
                android:paddingLeft="10dp"
                android:paddingRight="10dp"
                android:paddingTop="10dp"
                android:text="# Persons"
                android:textStyle="bold" />

            <TextView
                android:id="@+id/textView5"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:paddingLeft="10dp"
                android:paddingRight="10dp"
                android:paddingTop="20dp"
                android:text="Price Per Person"
                android:textStyle="bold" />
        </LinearLayout>

        <LinearLayout
            android:id="@+id/textfieldLayoutRight"
            android:layout_width="166dp"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <EditText
                android:id="@+id/textPrijsPerLiter"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:ems="10"
                android:inputType="numberDecimal" />

            <EditText
                android:id="@+id/textVerbruik"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_gravity="center_horizontal"
                android:ems="10"
                android:inputType="numberDecimal" />

            <EditText
                android:id="@+id/textAfstand"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:ems="10"
                android:inputType="numberDecimal" />

            <EditText
                android:id="@+id/textAantalPersonen"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_gravity="center_horizontal"
                android:ems="10"
                android:imeOptions="actionGo"
                android:inputType="numberDecimal" />

            <TextView
                android:id="@+id/textViewPPP"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:paddingLeft="10dp"
                android:paddingTop="20dp"
                android:textAppearance="?android:attr/textAppearanceLarge"
                android:textColor="#ffff000f"
                android:textStyle="bold" />

        </LinearLayout>

    </LinearLayout>


    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:orientation="vertical">

        <LinearLayout
            android:id="@+id/linearLayout"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="100dp"
            android:layout_marginTop="10dp"
            android:orientation="vertical">


            <Button
                android:id="@+id/btnBereken"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="Calculate"
                android:textStyle="bold" />

            <Button
                android:id="@+id/btnReset"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Reset all textfields"
                android:textStyle="bold" />


            <Button
                android:id="@+id/btnLoad"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Load latest results"
                android:textStyle="bold" />

        </LinearLayout>

        <com.google.android.gms.ads.AdView
            android:id="@+id/adView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            ads:adSize="SMART_BANNER"
            ads:adUnitId="MY_ID" />
    </LinearLayout>

</RelativeLayout>

Answer 1

You can:

1. Give up second linear layout and move button layout and ad layouts to main layout. Stick ad layout to bottom and declare it BEFORE button layout. Set buttons adjustments to layout_below="textfieldlayout" and layout_above="ad" instead of layout_alignParentBottom="true".

2. Consider using linear layout with weightSum. Every parent layout should have weightSum=100, every child will respectively have % of space. From my point of view this way would be the best, because views will position equally for merely all devices and even layout tree depth will remain the same. You'll only have to change the parent layout to LinearLayout and set weights.