Fragment基本使用（三）——与Activity之间传递数据

一、Fragment向Activity传递数据

1，Fragment
在Fragment中定义一个接口，然后在onAttach(Activity activity)方法中取得这个接口的实现。

/**
 * Created by chourongqishi on 16/9/21.
 */
public class FirstFragment extends Fragment {

    private TransDataToActivityListener listener;

    public interface TransDataToActivityListener {
        public void setDatas(String datas);
    }

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable
    Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.fragment_first, container, false);
        listener.setDatas("向Activity传递数据");
        return view;
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);

        try {
            listener = (TransDataToActivityListener) context;
        } catch (ClassCastException e) {
            e.printStackTrace();
        }
    }
}

2，Activity接收数据
Activity中实现Fragment定义的接口，然后取得数据

public class MainActivity extends FragmentActivity implements FirstFragment
        .TransDataToActivityListener {


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //创建要添加的Fragment对象
        FirstFragment firstFragment = new FirstFragment();
        //获取Fragment管理器
        FragmentManager manager = getSupportFragmentManager();
        //获取事物管理器
        FragmentTransaction transaction = manager.beginTransaction();
        //添加Fragment
        transaction.add(R.id.fl_container, firstFragment);
        //提交事物
        transaction.commit();

    }

    /**
     * 实现Fragment中的接口，获取数据
     *
     * @param datas
     */
    @Override
    public void setDatas(String datas) {
        Toast.makeText(this, datas, Toast.LENGTH_SHORT).show();
    }
}

二、Activity向Fragment传递数据

1，Activity：

/**
     * 实现Fragment中的接口，获取数据
     *
     * @param datas
     */
    @Override
    public void setDatas(String datas) {
        //获取Fragment管理器
        FragmentManager manager = getSupportFragmentManager();
        //获取事物管理器
        FragmentTransaction transaction = manager.beginTransaction();
        //创建一个新Fragment对象
        NewFragment newFragment = new NewFragment();
        //添加数据
        Bundle bundle = new Bundle();
        bundle.putString("datas", datas);
        //向Fragment传递数据
        newFragment.setArguments(bundle);
        //替换Fragment
        transaction.replace(R.id.fl_container, newFragment);
        //将上一个Fragment加入回退栈
        transaction.addToBackStack(null);
        //提交事物
        transaction.commit();

    }

2，Fragment接收数据

/**
 * Created by chourongqishi on 16/9/21.
 */
public class NewFragment extends Fragment {
    private TextView tvShowDatas;
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable
    Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.fragment_new,container,false);
        tvShowDatas = (TextView) view.findViewById(R.id.tv_show_datas);
        Bundle bundle = getArguments();
        String datas = bundle.getString("datas");
        tvShowDatas.setText(datas);

        return view;
    }
}