08_android入门_listView的几种Adaptor的实现_ArrayAdapter

public List<String> findAllNames() {
List<String> names=new ArrayList<String>();
SQLiteDatabase db=databaseHelper.getWritableDatabase();
Cursor c=db.rawQuery("select username from user",null);
while(c.moveToNext()){
names.add(c.getString(c.getColumnIndex("username")));
}
return names;
}

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// 设置显示的视图
setContentView(R.layout.activity_main);

//获取显示的数据 Model
databaseHelper=new DatabaseHelper(this);
//userDao=new UserDaoImpl(databaseHelper);
//查询获取的数据
//entities=userDao.findAll();
UserDaoImpl userDaoImpl=new UserDaoImpl(databaseHelper);
names=userDaoImpl.findAllNames();

//获取控件对象
lv_user=(ListView) findViewById(R.id.lv_user);//获取显示的视图

//控制层 显示item布局
//ArrayAdapter<User> adapter=new ArrayAdapter<User>(this, android.R.layout.simple_list_item_1,entities);
ArrayAdapter<String> adapter=new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,names);
//ArrayAdapter<String> adapter=new ArrayAdapter<>(this, android.R.layout.simple_expandable_list_item_1, android.R.id.text1, names);

//设置显示的视图
lv_user.setAdapter(adapter);
//注册事件
lv_user.setOnItemClickListener(this);
}