Extra white space at the bottom of screen

Question

I have a white space at the bottom of the screen ..it doesn't go even when scrolling the expandable listview, those are two pictures from the emulator to explain the matter : https://i.imgur.com/ivsRcoX.png
https://i.imgur.com/twKmHG2.png

This is my code: Mainactivity.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main3"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/white"
    tools:context=".MainActivity"
    >
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">
        <include layout="@layout/app_bar_main"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>

    </LinearLayout>
    <android.support.design.widget.NavigationView
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        app:menu="@menu/navigation_menu"
        android:layout_gravity="start"
        android:id="@+id/nv3"
        android:background="@color/list2"
        app:headerLayout="@layout/naviagtion_header2"
        >

    </android.support.design.widget.NavigationView>
</android.support.v4.widget.DrawerLayout>

app_bar_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:context=".MainActivity">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="192dp"
        android:fitsSystemWindows="true">

        <android.support.design.widget.CollapsingToolbarLayout
            android:id="@+id/collapsing_toolbar"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_scrollFlags="scroll|exitUntilCollapsed"
            android:fitsSystemWindows="true"
            app:contentScrim="?attr/colorPrimaryDark"
            app:expandedTitleMarginStart="48dp"
            app:expandedTitleMarginEnd="64dp">

            <ImageView
                android:id="@+id/imagetoolbar"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:scaleType="centerCrop"
                android:fitsSystemWindows="true"
                app:layout_collapseMode="parallax" />

            <android.support.v7.widget.Toolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
                app:layout_collapseMode="pin" />
        </android.support.design.widget.CollapsingToolbarLayout>
    </android.support.design.widget.AppBarLayout>

    <include layout="@layout/content_main" />


</android.support.design.widget.CoordinatorLayout>

content_main.xml

<android.support.v4.widget.SwipeRefreshLayout android:id="@+id/swipeToRefresh"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <ExpandableListView
        android:id="@+id/expandableListview"
        android:layout_height="match_parent"
        android:layout_width="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"
        android:divider="@android:color/white"
        android:dividerHeight="1.5dp"
        android:groupIndicator="@drawable/settings_selector"


        />

</android.support.v4.widget.SwipeRefreshLayout>

Answer 1

you should change the height of your AppBarLAyout in app_bar_main.xml

from

 ` <android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="192dp"
    android:fitsSystemWindows="true">`

into

 <android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true">

and build the project or refresh the layout.

Answer 2

I solved the problem chnaging wrap_content to 'match_parent'

 <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">
        <include layout="@layout/app_bar_main"
            android:layout_width="match_parent"
            android:layout_height="match_parent"/>