java - 从 Activity 中将文本设置为 Fragment

Question

我徒劳地尝试简单地从 FormActivity 中获取值并使用它来填充 Fragment 中的 EditText。我必须等待 Activity 从远程服务器检索值并用它填充本地 SQLite 表，这意味着我在 fragment 中尝试过的解决方案都不起作用(空错误，因为它还没有那么早填充)。我需要帮助。

FormActivity.java的相关部分

public void DrawText() {
        // Fetching user details from sqlite
        HashMap<String, String> user = db.getUserDetails();

        if (user.size() != 0) {
            Log.e(TAG, "string surname: " + surname);

            // Displaying the user details on the fragment

            FirstFragment f1 = new FirstFragment();

            //put info into a bundle to pass to fragments
            Bundle drawbundle = new Bundle();
            drawbundle.putString("surname", surname);

            f1.setArguments(drawbundle);

            FragmentManager FM = getSupportFragmentManager();
            FragmentTransaction FT = FM.beginTransaction();
            FT.add(R.id.something, f1);
            FT.commit();

        }else{
            Log.e(TAG, "table was empty");
        }
    }

    private class MyPagerAdapter extends FragmentPagerAdapter {

        public MyPagerAdapter(FragmentManager fm) {

            super(fm);
        }

        @Override
        public Fragment getItem(int pos) {
            switch(pos) {

                case 0: return FirstFragment.newInstance("@string/form_instruct");
                case 1: return SecondFragment.newInstance("SecondFragment, Instance 1");
                case 2: return ThirdFragment.newInstance("ThirdFragment, Instance 1");
                case 3: return FourthFragment.newInstance("FourthFragment, Instance 1");
                //case 4: return FifthFragment.newInstance("ThirdFragment, Instance 3");
                default: return FirstFragment.newInstance("FirstFragment, Default");

            }
        }

显然，id.something不正确，我不知道如何获取id。我读到我可以使用标签，但我的尝试没有成功。我尝试了以下方法:

FirstFragment fragA = (FirstFragment) getSupportFragmentManager().findFragmentByTag("fragA");

这是我的 FirstFragment.java

public class FirstFragment extends android.support.v4.app.Fragment {

    //create variables & Logcat tag
    private static final String TAG = FirstFragment.class.getSimpleName();
    private EditText inputTitle;
    private EditText inputName;
    private EditText inputSurname;
    //private SQLiteHandler db;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.fragment_first, container, false);
        TextView tv = (TextView) v.findViewById(R.id.tvFragFirst);
        tv.setText(getArguments().getString("msg"));

        inputSurname = (EditText) getActivity().findViewById(R.id.surnameText);
        inputSurname.setText(getArguments().getString("surname"));

        return v;
    }

    public static FirstFragment newInstance(String text) {

        FirstFragment f = new FirstFragment();
        Bundle b = new Bundle();
        b.putString("msg", text);

        f.setArguments(b);

        return f;
    }

我正在绕这个圈子，有人可以帮忙吗？

Answer 1

如果您使用 ContentProvider，您可以使用 ContentObserver 在表格填满以及调用 onChange 时收到通知，您可以更新 TextView。如果您没有使用 ContentProvider，则可以使用 LocalBroadcastManger 和 BroadcastReceiver 来实现相同的效果