activity_main.xml(zhou3)

    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"
    tools:context="com.example.disanzhoua3.MainActivity">


            android:id="@+id/listview"
        android:layout_width="match_parent"
        android:layout_height="match_parent">