Adapter基本用法

1. 使用流程

2. ArrayAdapter

new ArrayAdapter<?>(context, textViewResourceId, objects)

  context：上下文

  textViewResourceId：列表项的布局文件id

  objects：数据源（数组或集合）

public class MainActivity extends Activity {

private ListView myListView;
private ArrayAdapter<String>arrayAdapter;

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

    //新建数据源
    String[] data = {"初探ListView","初探ListView","初探ListView","初探ListView"};
    //新建适配器并绑定数据源
    adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, data);
    //设置适配器
    myListView = (ListView) findViewById(R.id.myListView);
    myListView.setAdapter(arrayAdapter);
}

}

3. SimpleAdapter

new SimpleAdapter(context, data, resource, from, to)

  context：上下文

  data：List> data，数据源必须是一个泛型为Map<String, ?>的集合。其中，集合中的每一个Map对应ListView中的一项。

  resource：列表项的布局文件id

  from：Map中的键名

  to：列表项的布局文件中的组件id

public class MainActivity extends Activity {

    private ListView myListView;
    private SimpleAdapter simpleAdapter;
    private List<Map<String, Object>> data;

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

        //新建数据源
        data = new ArrayList<Map<String, Object>>();
        for (int i = 0; i < 20; i++) {
            Map<String, Object>map = new HashMap<String, Object>();
            map.put("img", R.mipmap.ic_launcher);
            map.put("text", "初识simpleAdapter");
            data.add(map);
        }
        //新建适配器并绑定数据源
        simpleAdapter = new SimpleAdapter(this, getData(), R.layout.item, new String[]{"img", "text"}, new int[]{R.id.img, R.id.text});
        //设置适配器
        myListView = (ListView) findViewById(R.id.myListView);
        myListView.setAdapter(simpleAdapter);

    }
}