Question

我使用Bundle在片段之间传递数据。但是，我遇到了一些问题。我的Bundle无法正常工作，我不知道为什么。因为我像以前一样做所有事情。

这是我的活动：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_jegyek);

    BottomNavigationView bottomNav = findViewById(R.id.lista_navigation);
    bottomNav.setOnNavigationItemSelectedListener(navListener);

    if (savedInstanceState == null) {
        getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container_lista,
                new Tantargylista()).commit();
    }
}

private BottomNavigationView.OnNavigationItemSelectedListener navListener =
    new BottomNavigationView.OnNavigationItemSelectedListener() {
        @Override
        public boolean onNavigationItemSelected(@NonNull MenuItem item) {
            Fragment selectedFragment = null;

            switch (item.getItemId()) {
                case R.id.nav_tantargylista:
                    selectedFragment = new ObjectList();
                    break;
                case R.id.nav_dolgozatlista:
                    selectedFragment = new ExamList();
                    break;
            }

            getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container_lista,
                    selectedFragment).commit();

            return true;
        }
    };
}

我的第一个片段：

View v;
DB mydb;
ListView listView;
String teszt;

public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    v = inflater.inflate(R.layout.fragment_objectlist, container, false);

    listView = (ListView)v.findViewById(R.id.Jegyekview);
    mydb = new DB(getActivity());

    final ArrayList<String> thelist = new ArrayList<>();
    Cursor data = mydb.getTantargynev();

    if (data.getCount() == 0) {
        Toast.makeText(getActivity(), "Empty", Toast.LENGTH_SHORT).show();

    } else {
        while (data.moveToNext()) {
            thelist.add(data.getString(0));
        ListAdapter listadapter = new ArrayAdapter<>(getActivity(), android.R.layout.simple_list_item_1, thelist);
        listView.setAdapter(listadapter);
    }

    listView.setOnItemClickListener(
            new AdapterView.OnItemClickListener() {
                @Override
                public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                    teszt = thelist.get(i);

                    Bundle bundle = new Bundle();
                    bundle.putString("test", teszt);

                    Fragment targyAdatok = new targyAdatok();

                    Fragment jegyekAllando = new jegyekAllando();
                    jegyekAllando.setArguments(bundle);
                    FragmentTransaction FragTan = getActivity().getSupportFragmentManager().beginTransaction();
                    FragTan.replace(R.id.jegyekMenu, targyAdatok);
                    FragTan.commit();
                }
            }
        });
    }

    return v;
}

第二个Fragment有一个Button。如果按下Button，则打开第三个Fragment。

Button button = (Button)v.findViewById(R.id.elemzes);
elemzes.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {

        Fragment jegyekAllando = new jegyekAllando();
        FragmentTransaction FragTan2 = getFragmentManager().beginTransaction();
        FragTan2.replace(R.id.fragment_container_lista,jegyekAllando);
        FragTan2.commit();
    }
});

我的第三个片段：

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

    View rootView = inflater.inflate(R.layout.fragment_jegyek_allando, container, false);

    Bundle bundle = getArguments();
    String jegyAtlagSt = bundle.getString("test");
    //Here crash the program. :/

    return rootView;
}

Answer 1

打开第三个// Remove ID foreach($server_data as $sd) { unset($sd['id']); } unset($server_data['id']); PRINT_R($server_data);时，您没有从第二个Fragment传递任何内容。因此，您需要执行以下操作。

Fragment

Answer 2

我认为问题是您的第二个片段没有将代码中的束从第一个片段传递到第三个片段

Button button = (Button)v.findViewById(R.id.elemzes);
    elemzes.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            Fragment jegyekAllando = new jegyekAllando();
            FragmentTransaction FragTan2 = getFragmentManager().beginTransaction();
            FragTan2.replace(R.id.fragment_container_lista,jegyekAllando);
            FragTan2.commit();
        }
    });

将数据从片段传递到片段错误

2 个答案: