Question

有两个片段A和B，片段A有Textview，片段B有edittext和按钮。点击FragmentB中的提交需要使用Edittext文本更新FragmentA中的textview。

如何在片段之间进行通信？

Answer 1

在这个例子中，FragmentA调用notify。 INotifier

public interface INotifier {
    public void notify(Object data);
}

的Utils

public class Utils {
    public static INotifier notifier;
}

FragmentA

public FragmentA extends Fragment {

   public void onCreateView(...) {

   }

   public void inSomeMethod() {
        if (Utils.notifier != null) {
           Utils.notifier.notify(data);
        }
   }
}

FragmentB

public FragmentB extends Fragment implements INotifier {

   public void onCreateView(...) {
       Utils.notifier = this;   
   }

   @Override
   public void notify(Object data) {
       // handle data
   }
}

Answer 2

您需要首先交互活动，这将与第二个片段进行交互。并且还阅读了有关如何操作的文章。

https://developer.android.com/guide/components/fragments.html#CommunicatingWithActivity

Answer 3

Fragments之间的通信是使用Listeners完成的。如果要更新片段，请使用侦听器告诉MainActivity按照Google http://developer.android.com/training/basics/fragments/communicating.html的建议更新第二个片段。在Fragment中创建界面，并在Activity

中实施此界面

Fragment中的监听器

public interface FragmentUpdateInterface {
        void updateFragment(String newText);
}

@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);

    // This makes sure that the container activity has implemented
    // the callback interface. If not, it throws an exception
    try {
        mCallback = (FragmentUpdateInterface ) activity;
    } catch (ClassCastException e) {
        throw new ClassCastException(activity.toString()
                + " must implement FragmentUpdateListener");
    }
}

@Override
    public void onListItemClick(ListView l, View v, int position, long id) {
        // Send the event to the host activity
        mCallback.updateFragment("New Text");
    }

<强> MainActivity 在MainActivity中实现片段为

public static class MainActivity extends Activity
    implements MyFragment.FragmentUpdateListener{

public void updateFragment(String newText) {
OtherFragment otherFrag = (OtherFragment)
                getSupportFragmentManager().findFragmentById(R.id.other_fragment);

        if (otherFrag != null) {
            otherFrag.updateFragment(newText);
        } else {
            // Otherwise, we're in the one-pane layout and must swap frags...

            // Create fragment and give it an argument for the selected article
            OtherFragment otherFrag = new OtherFragment();
            Bundle args = new Bundle();
            args.putInt(ArticleFragment.ARG_POSITION, position);
            otherFrag.setArguments(args);

            FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
            transaction.replace(R.id.fragment_container, otherFrag);
            transaction.addToBackStack(null);

            // Commit the transaction
            transaction.commit();
        }
    }

希望这有帮助。

<强>更新

您也可以使用LocalBroadcastManager.getInstance().sendBroadcast()通知另一个片段。

如何在android中从子片段更新Fragment中的视图

3 个答案: