android_listView_适配器Adapter的使用

private void show() {
		List<Person> persons = personService.getScrollData(0, 20);//listView存放的数据
		List<HashMap<String, Object>> data = new ArrayList<HashMap<String,Object>>();
		for(Person person : persons){
			HashMap<String, Object> item = new HashMap<String, Object>();
			item.put("name", person.getName());
			item.put("phone", person.getPhone());
			item.put("amount", person.getAmount());
			item.put("id", person.getId());
			data.add(item);
		}
		SimpleAdapter adapter = new SimpleAdapter(this, data, R.layout.item,
				new String[]{"name", "phone", "amount"}, new int[]{R.id.name, R.id.phone, R.id.amount});
		
		listView.setAdapter(adapter);
		
	}

public class PersonAdapter extends BaseAdapter {
	private List<Person> persons;//在绑定的数据
	private int resource;//绑定的条目界面
	private LayoutInflater inflater;
}

private void show2() {
		Cursor cursor = personService.getCursorScrollData(0, 20);//listView存放的数据

		SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, R.layout.item, cursor,
				new String[]{"name", "phone", "amount"}, new int[]{R.id.name, R.id.phone, R.id.amount});
		listView.setAdapter(adapter);
	}

//自定义适配器
	private void show3() {
		List<Person> persons = personService.getScrollData(0, 20);//listView存放的数据
		PersonAdapter adapter = new PersonAdapter(this, persons, R.layout.item);
		listView.setAdapter(adapter);
	}

public PersonAdapter(Context context, List<Person> persons, int resource) {
		this.persons = persons;//数据源，listView要放的数据
		this.resource = resource;//每个条目的View的界面id
		inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
	}

	@Override
	public int getCount() {
		return persons.size();//数据总数
	}

	@Override
	public Object getItem(int position) {
		return persons.get(position);
	}

	@Override
	public long getItemId(int position) {
		return position;
	}

	@Override
	public View getView(int position, View convertView, ViewGroup parent) {
		TextView nameView = null;
		TextView phoneView = null;
		TextView amountView = null;
		if(convertView==null){//条目重用
			convertView = inflater.inflate(resource, null);//生成条目界面对象
			nameView = (TextView) convertView.findViewById(R.id.name);
			phoneView = (TextView) convertView.findViewById(R.id.phone);
			amountView = (TextView) convertView.findViewById(R.id.amount);
			
			ViewCache cache = new ViewCache();
			cache.nameView = nameView;
			cache.phoneView = phoneView;
			cache.amountView = amountView;			
			convertView.setTag(cache);
		}else{
			ViewCache cache = (ViewCache) convertView.getTag();
			nameView = cache.nameView;
			phoneView = cache.phoneView;
			amountView = cache.amountView;
		}
		Person person = persons.get(position);
		//下面代码实现数据绑定
		nameView.setText(person.getName());
		phoneView.setText(person.getPhone());
		amountView.setText(person.getAmount().toString());
		
		return convertView;
	}
	
	private final class ViewCache{
		public TextView nameView;
		public TextView phoneView;
		public TextView amountView;
	}

}