I'm trying to pass the user information from MainActivity to one of the fragments in my NavigationHeader and i keep getting a NullPointerException everytime i try to setText in the Fragment.
I tried using the Bundle and Interface approach before trying ViewModel. Also getActivity() warns me that it's null.
public class MainActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {
private DrawerLayout drawer;
//NavHeader
private TextView header_name, header_email;
//SessionManager
SessionManager sessionManager;
//maps
private static final String TAG = "MainActivity";
private static final int ERROR_DIALOG_REQUEST = 9001;
private static final String FINELOCATION = Manifest.permission.ACCESS_FINE_LOCATION;
private static final String COURSELOCATION = Manifest.permission.ACCESS_COARSE_LOCATION;
private Boolean mLocationPermissionsGranted = false;
private static final int LOCATION_PERMISSION_REQUEST_CODE = 1234;
private static final float DEFAULT_ZOOM = 15f;
private FusedLocationProviderClient mFusedLocationProviderClient;
private GoogleMap mMap;
String pontopartida, pontochegada;
private EditText ponto_partidaInput, ponto_chegadaInput;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//GET USER DATA
sessionManager = new SessionManager(this);
sessionManager.checkLogin();
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
View headerView = navigationView.getHeaderView(0);
header_name = (TextView) headerView.findViewById(R.id.header_name);
header_email = (TextView) headerView.findViewById(R.id.header_email);
HashMap<String, String> user = sessionManager.getUserDetail();
String mName = user.get(sessionManager.NAME);
String mEmail = user.get(sessionManager.EMAIL);
header_name.setText(mName);
header_email.setText(mEmail);
//Navigation Drawer
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
drawer = findViewById(R.id.drawer_layout);
navigationView.setNavigationItemSelectedListener(this);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.addDrawerListener(toggle);
toggle.syncState();
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {
switch (menuItem.getItemId()){
case R.id.nav_myaccount:
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, new MyAccountFragment()).commit();
break;
case R.id.nav_settings:
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, new SettingsFragment()).commit();
break;
case R.id.nav_logout:
sessionManager.logout();
break;
case R.id.nav_share:
Toast.makeText(this, "Shared", Toast.LENGTH_SHORT).show();
break;
}
drawer.closeDrawer(GravityCompat.START);
return true;
}
@Override
public void onBackPressed() {
if(drawer.isDrawerOpen(GravityCompat.START)){
drawer.closeDrawer(GravityCompat.START);
}else{
super.onBackPressed();
}
}
}
and MyAccountFragment
public class MyAccountFragment extends Fragment {
private SharedViewModel viewModel;
private EditText account_name;
private EditText account_email;
protected FragmentActivity mActivity;
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_myaccount, container, false);
account_name = (EditText) view.findViewById(R.id.name_accountfrag);
account_email = (EditText) view.findViewById(R.id.email_accountfrag);
viewModel.setText(account_name.getText().toString());
return view;
}
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
viewModel = ViewModelProviders.of(getActivity()).get(SharedViewModel.class);
viewModel.getText().observe(getViewLifecycleOwner(), new Observer<String>() {
@Override
public void onChanged(@Nullable String s) {
account_name.setText(s);
}
});
}
}
Also here is my error log
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.tiago.teleperformance, PID: 9236
java.lang.NullPointerException: Attempt to invoke virtual method 'void com.example.tiago.teleperformance.SharedViewModel.setText(java.lang.String)' on a null object reference
at com.example.tiago.teleperformance.MyAccountFragment.onCreateView(MyAccountFragment.java:42)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:2439)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1460)
at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1784)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1852)
at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:802)
at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2625)
at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2411)
at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2366)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2273)
at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:733)
at android.os.Handler.handleCallback(Handler.java:789)
at android.os.Handler.dispatchMessage(Handler.java:98)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6541)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
I was expecting it to update the information in the Fragment with the same Name and Email in the MainActivity as soon as i opened it. Instead it crashes. Can anyone help me?
