可扩展列表视图下的空白区域，如何使其消失？

Question

我尝试放大 ListView 以使其填满屏幕，但没办法。 这是布局代码：

     <?xml version="1.0" encoding="utf-8"?>

<LinearLayout 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:orientation="vertical"
              app:layout_collapseParallaxMultiplier="0.0">

    <android.support.v7.widget.Toolbar
        android:id="@+id/my_toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
        app:popupTheme="@style/ThemeOverlay.AppCompat.Light"/>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@color/colorPrimary"
            android:orientation="horizontal">

            <TextView
                android:id="@+id/textViewweight"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginBottom="5dp"
                android:layout_marginLeft="5dp"
                android:layout_marginRight="5dp"
                android:layout_marginTop="5dp"
                android:layout_weight="1"
                android:textAlignment="textEnd"
                android:textAppearance="@android:style/TextAppearance.Material.Small"
                app:layout_constraintHorizontal_bias="0.473"
                app:layout_constraintLeft_toRightOf="@+id/textViewdrug"
                app:layout_constraintRight_toLeftOf="@+id/textViewage"
                app:layout_constraintTop_toTopOf="parent"/>

            <TextView
                android:id="@+id/textViewage"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginBottom="5dp"
                android:layout_marginLeft="5dp"
                android:layout_marginRight="5dp"
                android:layout_marginTop="5dp"
                android:layout_weight="1"
                android:textAlignment="center"
                android:textAppearance="@android:style/TextAppearance.Material.Small"
                app:layout_constraintHorizontal_bias="0.919"
                app:layout_constraintLeft_toLeftOf="parent"
                app:layout_constraintRight_toRightOf="parent"
                app:layout_constraintTop_toTopOf="parent"/>

            <TextView
                android:id="@+id/textViewdrug"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginBottom="5dp"
                android:layout_marginLeft="5dp"
                android:layout_marginRight="5dp"
                android:layout_marginTop="5dp"
                android:layout_weight="1"
                android:textAlignment="textStart"
                android:textAppearance="@android:style/TextAppearance.Material.Small"
                app:layout_constraintHorizontal_bias="0.095"
                app:layout_constraintLeft_toLeftOf="parent"
                app:layout_constraintRight_toRightOf="parent"
                app:layout_constraintTop_toTopOf="parent"/>

        </LinearLayout>

        <ExpandableListView
            android:id="@+id/idListView"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@color/graymillidos"
            />

    </LinearLayout>

我的代码有错误吗？

以下是结果：