ArrayAdapter SimpleAdapter SimpleCursorAdapter 各种适配器的区别

最新推荐文章于 2020-03-03 23:05:33 发布

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#baseadapter #SimpleAdapter #SimpleCursorAdapter #ArrayAdapter #android 适配器

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本文详细介绍了Android中ListView的三种适配器：ArrayAdapter、SimpleAdapter和SimpleCursorAdapter的使用方法及应用场景。ArrayAdapter适用于简单的数组数据展示；SimpleAdapter支持更复杂的布局，如包含图片和多个文本项；SimpleCursorAdapter则专门用于展示数据库查询结果。

数据源不同而已
1. String[]: ArrayAdapter
2. List<Map<String,?>>: SimpleAdapter
3. 数据库Cursor: SimpleCursorAdapter

使用ArrayAdapter（数组适配器）顾名思义，需要把数据放入一个数组以便显示。
android.R.layout.simple_list_item_1是系统定义好的布局文件只显示一行文字

SimpleAdapter能定义各种各样的布局出来，可以放上ImageView（图片），还可以放上Button（按钮），CheckBox（复选框）

=============================SimpleAdapter==========================

public class List3 extends ListActivity {

    List<Map<String, Object>> list;

    @Override
    public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);

       list = getListForSimpleAdapter(); //list为数据集合

       SimpleAdapter     adapter = new SimpleAdapter(this, list,   R.layout.item,
       new String[] { "BigText", "LittleText", "img" },
       new int[] { R.id.BigText,R.id.LittleText, R.id.img });

       //可以想成把一个放好数据的布局文件放入本界面中
       setListAdapter(adapter);
    }

    private List<Map<String, Object>> getListForSimpleAdapter() {
    List<Map<String,Object>> list=newArrayList<Map<String, Object>>(3);
           Map<String, Object> map = new HashMap<String, Object>();
           map.put("BigText", "Android");
           map.put("LittleText", "Google phone.");
           map.put("img", R.drawable.n);
           list.add(map);

           map = new HashMap<String, Object>();
           map.put("BigText", "Lenovo");
           map.put("LittleText", "Ophone");
           map.put("img", R.drawable.o);
           list.add(map);

           map = new HashMap<String, Object>();
           map.put("BigText", "Droid");
           map.put("LittleText", "Motorola");
           map.put("img", R.drawable.droid);
           list.add(map);

       return list;
    }
}

==============================SimpleCursorAdapter===================

注意：SimpleCursorAdapter是和数据库有关的东西，而sqlite数据库所要求的自动增长的 id  必须是 _id这中形式

public class List2 extends Activity {

    private ListView listView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        listView=new ListView(this);
       Cursorc=getContentResolver().query(People.CONTENT_URI,
       null, null, null, null);
        startManagingCursor(c);

        ListAdapter adapter = new SimpleCursorAdapter(this,
                 android.R.layout.simple_list_item_1,
                 c,
                 new String[] {People.NAME} ,
                 new int[] {android.R.id.text1});
        listView.setAdapter(adapter);
    setContentView(listView);
    }
}

====================ArrayAdapter===================================

public class List1 extends  Activity {

    private ListVeiw listView;
    @Override
    public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

       listView=new ListVeiw(this);
       listView.setAdapter(new ArrayAdapter<String>(this,
           android.R.layout.simple_list_item_1, mStrings));
      setContentVieww(listView);
        }

    private String[] mStrings = {
           "Abbaye de Belloc", "Abbaye du Mont des Cats",
           "Acorn", "Adelost", "Affidelice au Chablis",
           "Aisy Cendre", "Allgauer Emmentaler", "Alverca",
           "Ami du Chambertin", "Anejo Enchilado", "Anneau
           "Aragon", "Ardi Gasna", "Ardrahan", "Armenian
           "Asadero", "Asiago", "Aubisque Pyrenees", "Autun",
           "Babybel", "Baguette Laonnaise", "Bakers", "Bal"};
}