java - 将数据从 Fragment 传递到另一个 Fragment
问题描述
我正在寻找数周,但我无法解决我的问题。我想将数据从一个片段传递到另一个片段。
我尝试使用捆绑包和界面,但它们都不起作用。你能帮我解决这个问题吗?我会很感激我想从这个片段中传递数据,它的名字是“FragmentGelir”
public class FragmentGelir extends Fragment {
private Toolbar toolbarGelir;
private FloatingActionButton fabGelir;
private RecyclerView rvgelir;
private ArrayList<Gelirler> gelirlerArrayList;
private GelirlerAdapter adapter;
private Veritabani vt;
public double toplamgelir = 0.0;
public String anahtar;
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_gelir, container, false);
anahtar = "test";
FragmentHomepage fragmentHomepage = new FragmentHomepage();
Bundle bundle = new Bundle();
bundle.putString("anahtar", anahtar);
fragmentHomepage.setArguments(bundle);
fabGelir = rootView.findViewById(R.id.fabGelir);
toolbarGelir = rootView.findViewById(R.id.toolbarGelir);
rvgelir = rootView.findViewById(R.id.rvgelir);
toolbarGelir.setTitle("Gelir Ekle");
vt = new Veritabani(getActivity());
rvgelir.setHasFixedSize(true);
rvgelir.setLayoutManager(new LinearLayoutManager(getActivity()));
gelirlerArrayList = new GelirlerDatabaseAccessObject().tumGelirler(vt);
adapter = new GelirlerAdapter(getActivity(), gelirlerArrayList, vt);
rvgelir.setAdapter(adapter);
fabGelir.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
alertgoster();
}
});
for (Gelirler gel : gelirlerArrayList) {
toplamgelir = toplamgelir + gel.getGelirTutar();
}
toolbarGelir.setSubtitle("toplam Gelir: " + toplamgelir);
return rootView;
}
public void alertgoster() {
LayoutInflater layout = LayoutInflater.from(getActivity());
View tasarim = layout.inflate(R.layout.alert_gelir, null);
final EditText editTextGelir = tasarim.findViewById(R.id.editTextGider);
final EditText editTextGelirTutar = tasarim.findViewById(R.id.editTextGiderTutar);
final AlertDialog.Builder gelir = new AlertDialog.Builder(getActivity());
gelir.setTitle("Gelir Ekle");
gelir.setView(tasarim);
gelir.setPositiveButton("Ekle", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
String gelir_ekle = editTextGelir.getText().toString().trim();
Double gelir_tutar = Double.parseDouble(editTextGelirTutar.getText().toString().trim());
new GelirlerDatabaseAccessObject().GelirEkle(vt, gelir_ekle, gelir_tutar);
gelirlerArrayList = new GelirlerDatabaseAccessObject().tumGelirler(vt);
adapter = new GelirlerAdapter(getActivity(), gelirlerArrayList, vt);
rvgelir.setAdapter(adapter);
Toast.makeText(getContext().getApplicationContext(), gelir_ekle + " - " + gelir_tutar + " olarak Eklendi", Toast.LENGTH_SHORT).show();
}
});
gelir.setNegativeButton("İptal", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
});
gelir.create().show();
}
}
这是我的第二个片段,它应该获取数据“Fragmenthomepage”
public class FragmentHomepage extends Fragment {
private Toolbar toolbarHome;
private TextView textViewbugunGelir;
private TextView textViewbugunGider;
public String strtext;
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_homepage, container, false);
toolbarHome = rootView.findViewById(R.id.toolbarHome);
toolbarHome.setTitle("Gelir gider hesaplar");
textViewbugunGider = rootView.findViewById(R.id.textViewbugunGider);
strtext = getArguments().getString("anahtar"); //this is not working getting error "null object reference"
textViewbugunGelir = rootView.findViewById(R.id.textViewbugunGelir);
textViewbugunGelir.setText(strtext);
return rootView;
}
}
这是我的 MainActivity
public class MainActivity extends AppCompatActivity {
private BottomNavigationView bottom_navigation;
private Fragment temporaryFragment;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getSupportFragmentManager().beginTransaction().add(R.id.frame_holder, new FragmentHomepage()).commit();
bottom_navigation = findViewById(R.id.bottom_navigation);
bottom_navigation.setSelectedItemId(R.id.action_home);
bottom_navigation.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
if (item.getItemId() == R.id.action_home) {
temporaryFragment = new FragmentHomepage();
}
if (item.getItemId() == R.id.action_gelir) {
temporaryFragment = new FragmentGelir();
}
if (item.getItemId() == R.id.action_gider) {
temporaryFragment = new FragmentGider();
}
getSupportFragmentManager().beginTransaction().replace(R.id.frame_holder, temporaryFragment).commit();
return true;
}
});
}
}
解决方案
1-您可以使用接口,并使用此处描述的主机活动与其他片段共享数据。
开发者文档:https ://developer.android.com/training/basics/fragments/communicating
2-您可以使用视图模型通过您的主机活动在您的片段之间共享数据。这是现在推荐的片段之间数据共享的方式。使用视图模型在片段之间共享数据。
https://developer.android.com/topic/libraries/architecture/viewmodel#sharing
创建一个视图模型类:
// Item is your desired data type
public class SharedViewModel extends ViewModel {
private final MutableLiveData<Item> selected = new MutableLiveData<Item>();
public void select(Item item) {
selected.setValue(item);
}
public LiveData<Item> getSelected() {
return selected;
}
在您的 FragmentGelir 中:
public void onViewCreated(@NonNull View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
model = new ViewModelProvider(requireActivity()).get(SharedViewModel.class);
itemSelector.setOnClickListener(item -> {
model.select(item);
});
}
}
在您的 FragmentHomePage 中:
public void onViewCreated(@NonNull View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
SharedViewModel model = new ViewModelProvider(requireActivity()).get(SharedViewModel.class);
model.getSelected().observe(getViewLifecycleOwner(), item -> {
// Update the UI.
});
}
3-托管活动的基本用法
在主要活动中:
private DataType data;
public SetData(DataType data)
{
this.data = data;
}
public GetData()
{
return this.data;
}
在片段中设置数据:
((MainActivity) requireActivity()).SetData(data);
在片段中获取数据:
DataType data;
data = ((MainActivity) requireActivity()).GetData;
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