public class MainActivity extends AppCompatActivity {
  //數(shù)據(jù)源
  private List<String> data;
  //ListView控件
  private ListView mList;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    //獲取控件ID
    mList = (ListView)findViewById(R.id.mList);
    data = new ArrayList<>();
    //數(shù)據(jù)賦初值
    for(int i = 0; i < 20; i ++){
      data.add("數(shù)據(jù)項(xiàng)"+ i);
    }
    //創(chuàng)建適配器
    MyAdapter adapter = new MyAdapter(data);
    //設(shè)置適配器
    mList.setAdapter(adapter);

  }

}

public class MyAdapter extends BaseAdapter {
  //數(shù)據(jù)項(xiàng)
  private List<String> data;

  public MyAdapter(List<String> data) {
    this.data = data;
  }

  @Override
  /**
  * 返回?cái)?shù)據(jù)源的長度，表示ListView的item項(xiàng)顯示多少個(gè)
  */
  public int getCount() {
    return data == null ? 0 : data.size();
  }
  /**
   * 返回指定位置的 item 數(shù)據(jù)源的對象,這個(gè)方法為手動(dòng)調(diào)用,非設(shè)置適配器時(shí)候調(diào)用
   * @param position 指定位置
   * @return
   */
  @Override
  public Object getItem(int position) {
    return data.get(position);
  }

  /**
   * 返回指定位置的 item的標(biāo)記 id,很少使用到
   * @param position 指定位置
   * @return
   */
  @Override
  public long getItemId(int position) {
    return position;
  }

  /**
   * 工廠方法,設(shè)置好模板,返回視圖,每個(gè)視圖是怎么顯示出來的, 核心點(diǎn),怎么產(chǎn)生一個(gè)View, View 里面怎么  
   * 放置對應(yīng)的內(nèi)容
   * @param position 當(dāng)前加載的位置
   * @param convertView 復(fù)用的view
   * @param parent listview
   * @return
   */
  @Override
  public View getView(int position, View convertView, ViewGroup parent) {
    //獲取布局
    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item,null);
    //獲取布局中的TextView控件1
    TextView tv1 = (TextView) view.findViewById(R.id.mTv1);
    //設(shè)置控件1的數(shù)據(jù)
    tv1.setText(data.get(position));
    //獲取布局中的TextView控件2
    TextView tv2 = (TextView) view.findViewById(R.id.mTv2);
    //設(shè)置控件2數(shù)據(jù)
    tv2.setText(data.get(position));
    return view;
  }
}

  @Override
  public View getView(int position, View convertView, ViewGroup parent) {
    Log.i("TAG", "getView: " + position);
    if (convertView == null) {
      convertView = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, null);
    }
    TextView tv1 = (TextView) convertView.findViewById(R.id.mTv1);
    tv1.setText(data.get(position));
    TextView tv2 = (TextView) convertView.findViewById(R.id.mTv2);
    tv2.setText(data.get(position));
    return convertView;

  }
}