Adapter传递数据到Activity(接口回调)

Adapter代码
构造方法：

public ContactListAdapter(Context context, List<ImpUserInfoVo> list,                              QuickAlphabeticBar alpha, HashMap<Integer, Boolean> isSelected) {        this.ctx = context;        this.inflater = LayoutInflater.from(context);        this.list = list;        this.alphaIndexer = new HashMap<String, Integer>();        this.sections = new String[list.size()];        this.isSelected = isSelected;        for (int i = 0; i < list.size(); i++) {            String name = getAlpha(list.get(i).getSortKey());            if (!alphaIndexer.containsKey(name)) {                alphaIndexer.put(name, i);            }        }        mOnClickListener = (OnClickListener) context;        }

在Adaper中定义接口：

public interface OnClickListener {        public void setSelectedNum(int num);    }

Adapter调用接口

mOnClickListener.setSelectedNum(getSelectSize());

Activity代码
在Activty中实现接口

public class ContactListActivity extends Activity implements ContactListAdapter.OnClickListener{}//接口回调，显示已选择的人数    @Override    public void setSelectedNum(int num) {        haschoose.setText("已经选择" + num + "");    }