在片段之间导航时遇到麻烦

Question

我已经对这个问题进行了大约 4 个小时的调查，但我没有得到任何帮助。

总之，我正在尝试使用导航视图在Android Studio中的片段之间导航。我想从主片段转到服务片段。

第一个主页片段总是加载，但是当我单击服务项目时，片段服务加载，但主页中的数据也始终保留在片段上。

这是我的代码：

家庭片段类

public class HomeFragment extends Fragment {
private HomeViewModel homeViewModel;
private PieChart pieChart;
private UserService userService;
private Calendar calendar;
public View onCreateView(@NonNull LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
homeViewModel = ViewModelProviders.of(this).get(HomeViewModel.class);
View root = inflater.inflate(R.layout.fragment_home, container, false);
pieChart = root.findViewById(R.id.pieChart);
userService = UserRepository.getUserService();
getData();
return root;
}

private void getData(){
calendar = Calendar.getInstance();
int month = calendar.get(Calendar.MONTH)+1;
Log.i("INT MONTH", String.valueOf(month));
userService.getHoursPerService(String.valueOf(UserCache.empleado.getId_emp()),String.valueOf(month)).enqueue(new Callback<List<Servicio>>() {
@Override
public void onResponse(Call<List<Servicio>> call, Response<List<Servicio>> response) {
if(response.body().size() == 0){
pieChart.setNoDataText("Sin horas actuales.");
pieChart.setNoDataTextColor(ContextCompat.getColor(getContext(), R.color.colorPrimaryDark));
pieChart.invalidate();
}else{
List<Servicio> list = response.body();
List<PieEntry> pieEntries = new ArrayList<>();
for(int cont=0;cont<list.size();cont++){
pieEntries.add(new PieEntry(list.get(cont).getTotalHoras(), list.get(cont).getLugarServicio()));
}
SimpleDateFormat sdf = new SimpleDateFormat("MMMM");
String actual_month = sdf.format(calendar.getTime());
PieDataSet dataSet = new PieDataSet(pieEntries, getResources().getString(R.string.txt_hours_of)+" "+actual_month);
dataSet.setSliceSpace(3f);
dataSet.setSelectionShift(5f);
dataSet.setColors(ColorTemplate.MATERIAL_COLORS);
PieData data = new PieData(dataSet);
data.setValueTextSize(10f);
data.setValueTextColor(ContextCompat.getColor(getContext(), R.color.colorPrimaryDark));
pieChart.getDescription().setEnabled(true);
pieChart.getDescription().setText(getResources().getString(R.string.txt_hours_of)+" "+actual_month+".");
pieChart.getDescription().setTextSize(12f);
pieChart.getDescription().setTextColor(ContextCompat.getColor(getContext(), R.color.colorPrimaryDark));
pieChart.setExtraOffsets(5, 10, 5, 5);
pieChart.setDragDecelerationFrictionCoef(0.99f);
pieChart.setDrawHoleEnabled(true);
pieChart.setHoleColor(Color.WHITE);
pieChart.setTransparentCircleRadius(61f);
pieChart.animateY(2000, Easing.EaseInOutCubic);
pieChart.setEntryLabelColor(ContextCompat.getColor(getContext(),R.color.colorPrimaryDark));
pieChart.setData(data);
pieChart.invalidate();
}
}
@Override
public void onFailure(Call<List<Servicio>> call, Throwable t) {
}
});
}

}

服务片段类

public class ServicesFragment extends Fragment {
private ServicesViewModel servicesViewModel;
public View onCreateView(@NonNull LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
servicesViewModel = ViewModelProviders.of(this).get(ServicesViewModel.class);
View root = inflater.inflate(R.layout.fragment_myservices, container, false);
final TextView textView = root.findViewById(R.id.text_gallery);
servicesViewModel.getText().observe(this, new Observer<String>() {
@Override
public void onChanged(@Nullable String s) {
textView.setText(s);
}
});
return root;
}

}

主要活动

public class MainActivityView extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {
private AppBarConfiguration mAppBarConfiguration;
private NavigationView navigationView;
private ActionBarDrawerToggle toggle;
private TextView userNameNav;
private TextView userEmailNav;
private DrawerLayout drawer;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main_view);
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
/*FloatingActionButton fab = findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});*/
drawer = findViewById(R.id.drawer_layout);
navigationView = findViewById(R.id.nav_view);
// Passing each menu ID as a set of Ids because each
// menu should be considered as top level destinations.
mAppBarConfiguration = new AppBarConfiguration.Builder(
R.id.nav_home, R.id.nav_myservices, R.id.nav_startservice)
.setDrawerLayout(drawer)
.build();
NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
NavigationUI.setupActionBarWithNavController(this, navController, mAppBarConfiguration);
NavigationUI.setupWithNavController(navigationView, navController);
View headerView = navigationView.getHeaderView(0);
navigationView.setNavigationItemSelectedListener(this);
userNameNav = headerView.findViewById(R.id.userNameNav);
userEmailNav = headerView.findViewById(R.id.userEmailNav);
userNameNav.setText(UserCache.empleado.getNombre()+" "+UserCache.empleado.getApellidos());
userEmailNav.setText(UserCache.empleado.getEmail());
navigationView.bringToFront();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main_activity_view, menu);
return true;
}

@Override
public boolean onSupportNavigateUp() {
NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
return NavigationUI.navigateUp(navController, mAppBarConfiguration)
|| super.onSupportNavigateUp();
}
@Override
public void onBackPressed() {
if(drawer.isDrawerOpen(GravityCompat.START)){
drawer.closeDrawer(GravityCompat.START);
}else{
AlertDialog.Builder alerta = new AlertDialog.Builder(this);
alerta.setTitle(getResources().getString(R.string.txt_dialog_exit_app));
alerta.setPositiveButton(getResources().getString(R.string.txt_yes_option), new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
finish();
}
});
alerta.setNegativeButton(getResources().getString(R.string.txt_no_option), new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
}
});
alerta.show();
}
}
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {
switch (menuItem.getItemId()){
case R.id.nav_home:
getSupportFragmentManager().popBackStack(null,FragmentManager.POP_BACK_STACK_INCLUSIVE);
getSupportFragmentManager().beginTransaction().replace(R.id.nav_host_fragment,new HomeFragment()).commit();
case R.id.nav_myservices:
getSupportFragmentManager().popBackStack(null,FragmentManager.POP_BACK_STACK_INCLUSIVE);
getSupportFragmentManager().beginTransaction().replace(R.id.nav_host_fragment, new ServicesFragment()).commit();
//NavHostFragment.findNavController(new ServicesFragment());
break;
case R.id.nav_startservice:
getSupportFragmentManager().popBackStack(null,FragmentManager.POP_BACK_STACK_INCLUSIVE);
getSupportFragmentManager().beginTransaction().replace(R.id.nav_host_fragment, new StartServiceFragment()).commit();
break;
}
drawer.closeDrawer(GravityCompat.START);
return true;
}

}

onNavigationItemSelected是我进行导航的地方。

我尝试了一切，将约束布局更改为相对，将 xml 中的片段插入框架布局......

另外，我正在使用MVVM。

如果需要更多信息，我可以在这里发布。

PD：对不起，如果我发错了什么，这是我第一次来这里。

Answer 1

解决方案：我完全忘记打破导航项目选择的第一个案例。