代码1

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private ListView listView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
//        setContentView(R.layout.activity_main);

        listView = new ListView(this);
        listView.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_expandable_list_item_1,getData()));
        setContentView(listView);

    }

    private List<String> getData() {
        List<String> data = new ArrayList<String>();
        data.add("测试数据1");
        data.add("测试数据2");
        data.add("测试数据3");
        data.add("测试数据4");

        return data;
    }
}

代码2

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class MainActivity extends AppCompatActivity {

    private ListView listView;
    private ArrayAdapter<String> adapter;
    private String[] str = new String[] {"Android","Java","iPhone","Objective-C"};

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
//        setContentView(R.layout.activity_main);

        listView = new ListView(this);
        adapter = new ArrayAdapter<String>(this, android.R.layout.simple_expandable_list_item_1, str);
        listView.setAdapter(adapter);

        setContentView(listView);
    }
}

代码3 (XML 创建 ListView)

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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"
    tools:context=".MainActivity">

    <ListView
        android:id="@+id/listView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</android.support.constraint.ConstraintLayout>

MainActivity.java

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class MainActivity extends AppCompatActivity {

    private ListView listView;
    private ArrayAdapter<String> adapter;
    private String[] str = new String[] {"Android","Java","iPhone","Objective-C"};

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        listView = findViewById(R.id.listView);
        adapter = new ArrayAdapter<String>(this, android.R.layout.simple_expandable_list_item_1, str);
        listView.setAdapter(adapter);
    }
}