ArrayAdapter ,SimpleAdapter与SimpleCursorAdapter 区别

很多初学者肯定会对适配器感到困惑，其实他们就是数据源不同而已 。

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"};

}