Develop Reference

pass string from activity to fragment [duplicate]

This question already has answers here:
how to pass string data from activity to fragment?
(5 answers)
Closed 5 years ago.
My problem is passing string from activity to fragment. I researched for a whole day and my problem isn't solved.
activity :
if(email.matches(users.user1)&&password.matches(users.pass1)){
Intent intent = new Intent(LoginActivity.this,MainActivity.class);
Bundle bundle = new Bundle();
bundle.putString("user", users.name);
ProfileFragment fragobj = new ProfileFragment();
fragobj.setArguments(bundle);
startActivity(intent);
}
fragment :
public class ProfileFragment extends Fragment {
public static ProfileFragment newInstance() {
return new ProfileFragment();
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_profile, container, false);
String user = getArguments().getString("user");
TextView textView = v.findViewById(R.id.namef1);
textView.setText(user);
return inflater.inflate(R.layout.fragment_profile, container, false);
}
}
MainActivity
public class MainActivity extends Activity {
private BottomNavigationView mBottomNavigationView;
private Toolbar supportActionBar;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setupBottomNavigation();
if (savedInstanceState == null) {
loadHomeFragment();
}
}
private void setupBottomNavigation() {
mBottomNavigationView =findViewById(R.id.bottom_navigation);
mBottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.action_home:
loadHomeFragment();
return true;
case R.id.action_profile:
loadProfileFragment();
return true;
case R.id.action_settings:
loadSettingsFragment();
return true;
}
return false;
}
});
}
private void loadHomeFragment() {
HomeFragment fragment = HomeFragment.newInstance();
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.replace(R.id.fragment_frame, fragment);
ft.commit();
}
private void loadProfileFragment() {
ProfileFragment fragment = ProfileFragment.newInstance();
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.replace(R.id.fragment_frame, fragment);
ft.commit();
}
private void loadSettingsFragment() {
SettingsFragment fragment = SettingsFragment.newInstance();
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.replace(R.id.fragment_frame, fragment);
ft.commit();
}
public void setSupportActionBar(Toolbar supportActionBar) {
this.supportActionBar=supportActionBar;
}
}
as it shown in code user has login and one of his data display in a profile fragment . I wanna display this string as Textview in profilefragment .
anybody have an idea?

Move below part of code to the place where you are adding the ProfileFragment to Activity.
Bundle bundle = new Bundle();
bundle.putString("user", users.name);
ProfileFragment fragobj = new ProfileFragment();
fragobj.setArguments(bundle);

Bottom menu bar goes blank by clicking second time on menu options

I have a problem with my Bottom bar in android. when i click on the bottom menu options it goes blank. Please help me out to fine what is the basic problem. Where is am I wrong.
It shows no error or exception in logcat.
Here is my code
public class BottomBarActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_bottom_bar);
final BottomNavigationView bottomNavigationView = (BottomNavigationView) findViewById(R.id.navigation);
bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
// Fragment selectedFragment = null;
switch (item.getItemId()) {
case R.id.action_library:
FragmentLibrary fragmentLibrary = new FragmentLibrary();
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.frame_layout1, fragmentLibrary);
fragmentTransaction.commit();
Toast.makeText(BottomBarActivity.this, "Library", Toast.LENGTH_SHORT).show();
break;
case R.id.action_notification:
//002
Fragment selectedFragmentNotification = FragmentNotification.newInstance();
FragmentTransaction fragmentTransactionNotification = getSupportFragmentManager().beginTransaction();
fragmentTransactionNotification.replace(R.id.frame_layout1, selectedFragmentNotification);
fragmentTransactionNotification.commit();
Toast.makeText(BottomBarActivity.this, "Notifications", Toast.LENGTH_SHORT).show();
break;
case R.id.action_more:
Fragment selectedFragmentMore = FragmentMore.newInstance();
FragmentTransaction fragmentTransactionMore = getSupportFragmentManager().beginTransaction();
fragmentTransactionMore.replace(R.id.frame_layout1, selectedFragmentMore);
fragmentTransactionMore.commit();
Toast.makeText(BottomBarActivity.this, "More", Toast.LENGTH_SHORT).show();
break;
case R.id.action_discovered:
Fragment selectedFragmentMain = FragmentMain.newInstance();
FragmentTransaction fragmentTransactionMain = getSupportFragmentManager().beginTransaction();
fragmentTransactionMain.replace(R.id.frame_layout1, selectedFragmentMain);
fragmentTransactionMain.commit();
Toast.makeText(BottomBarActivity.this, "Discover", Toast.LENGTH_SHORT).show();
break;
}
return true;
}
});
//Manually displaying the first fragment
Fragment selectedFragment = FragmentMain.newInstance();
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.frame_layout1, selectedFragment);
fragmentTransaction.commit();
}
}
Here is the Fragment Class Code.
This fragment is called when I click one of the menu item.
public class FragmentLibrary extends Fragment {
private static final String ARG_POSITION = "position";
private int position;
private PagerSlidingTabStrip tabs_L;
private ViewPager pager_L;
public FragmentLibrary() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
final View view = inflater.inflate(R.layout.fragment_library, container, false);
pager_L = (ViewPager) view.findViewById(R.id.pagerL);
pager_L.setAdapter(new MyAdapterLibrary(getFragmentManager()));
tabs_L = (PagerSlidingTabStrip) view.findViewById(R.id.tabsL);
tabs_L.setViewPager(pager_L);
return view;
}
// ADAPTER CLASS
public class MyAdapterLibrary extends FragmentPagerAdapter {
private String[] titles = {
getString(R.string.tab_title_current_reading),
getString(R.string.tab_title_reading_lists),
getString(R.string.tab_title_history)
};
public MyAdapterLibrary(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return FragmentCurrentReading.newInstance(position);
case 1:
return FragmentReadingLists.newInstance(position);
case 2:
return FragmentHistory.newInstance(position);
}
return null;
}
#Override
public int getCount() {
return titles.length;
}
#Override
public CharSequence getPageTitle(int position) {
return titles[position];
}
}
}

how to handle multiple fragments onbackpressed

The Main Activity having bottom navigation and contains 5 fragments in it. Each fragments having multiple fragment inside. how to handle the onbackpressed in it.
Homepage.java
public class Homepage extends AppCompatActivity {
private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
= new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
Fragment selectedFragment = null;
switch (item.getItemId()) {
case R.id.home:
selectedFragment = Fragment_home.newInstance();
break;
case R.id.eventsfeed:
selectedFragment = Fragment_eventsfeed.newInstance();
break;
case R.id.events:
selectedFragment = Fragment_events.newInstance();
break;
case R.id.messages:
selectedFragment = Fragment_messages.newInstance();
break;
case R.id.settings:
selectedFragment = Fragment_settings.newInstance();
break;
}
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.content, selectedFragment);
transaction.commit();
return true;
}
};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.homepage);
Fragment fragmentnewview = new Fragment_home();
FragmentManager frMan = getSupportFragmentManager();
FragmentTransaction frTr = frMan.beginTransaction();
frTr.add(R.id.content,fragmentnewview);
frTr.commit();
BottomNavigationView navigation = (BottomNavigationView) findViewById(R.id.navigation);
navigation.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
BottomNavigationViewHelper.disableShiftMode(navigation);
}}
Fragment_home.java
public class Fragment_home extends Fragment {
public static Fragment_home newInstance(){
Fragment_home fragment=new Fragment_home();
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View view=inflater.inflate(R.layout.fragment_home, container, false);
CardView card=(CardView)view.findViewById(R.id.next_page_home_card);
card.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
view.setVisibility(View.GONE);
Fragment fragmentnewview = new Event_details();
FragmentManager frMan = getActivity().getSupportFragmentManager();
FragmentTransaction frTr = frMan.beginTransaction();
frTr.add(R.id.content,fragmentnewview);
frTr.commit();
}
});
return view;
}
}
Inside that Fragment_home.java i have a card view when it clicked it goes to next fragment Event_Details.java
Event_Details.java
public class Event_details extends Fragment {
Button add_comments;
ImageButton back;
public static Event_details newInstance(){
Event_details fragment=new Event_details();
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View view=inflater.inflate(R.layout.event_details, container, false);
add_comments=(Button)view.findViewById(R.id.add_comment);
back=(ImageButton)view.findViewById(R.id.back);
back.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
view.setVisibility(View.GONE);
Fragment fragmentnewview = new Fragment_home();
FragmentManager frMan = getActivity().getSupportFragmentManager();
FragmentTransaction frTr = frMan.beginTransaction();
frTr.add(R.id.content,fragmentnewview);
frTr.commit();
}
});
add_comments.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
view.setVisibility(View.GONE);
Fragment fragmentnewview = new Comments();
FragmentManager frMan = getActivity().getSupportFragmentManager();
FragmentTransaction frTr = frMan.beginTransaction();
frTr.add(R.id.content,fragmentnewview);
frTr.commit();
}
});
return view;
}
}
i have a button in Event_Details.java when clicked that it calls another fragment Comments.java
Comments.java
public class Comments extends Fragment {
ImageButton back;
public static Comments newInstance(){
Comments fragment=new Comments();
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View view=inflater.inflate(R.layout.add_your_comments, container, false);
back=(ImageButton)view.findViewById(R.id.back);
back.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
view.setVisibility(View.GONE);
Fragment fragmentnewview = new Event_details();
FragmentManager frMan = getActivity().getSupportFragmentManager();
FragmentTransaction frTr = frMan.beginTransaction();
frTr.add(R.id.content,fragmentnewview);
frTr.commit();
}
});
return view;
}
}
back.setOnClickListener is the image button to go back but i can't implement in the hardware back button.

You need to #Override your activity onBackPressed() method !!!
There are many good information and answers about your question ! if you want to become good programmer you need good research skills!!! :))
Try to research and solve the problem yourself . Write some code, and after all of it if you still can't resolve your problem i'll give you code for copy and paste :)

When you load a fragment, use addToBackStack(null) on the FragmentTransaction. If you do that, the back button will reverse the transaction.

#Override onBackPressed()
method as #L.Petrosyan told,
insideonBackPressed()get the current position of your viewpager usingviewPager.getCurrentItem();
it will return you anint` value. use that value to manage your code.

After two different fragments have been replaced, first fragment is recreated when on pressed back button

I have three fragment and one activity. It works this way:
[activity]-> [MainFragment]->[MenuFragment]->[SignUpFragment]
When [SignUpFragment] is back pressed, the [MainFragment] is created twice.
I tried setRetaInInstance(true) and I checked savedInstanceState but I can not prevent [MainFragment] recreating.
This is my MainActivity:
public class MainActivity extends AppCompatActivity {
public Bundle mSavedInstanceState;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mSavedInstanceState = savedInstanceState;
setContentView(R.layout.activity_main);
}
#Override
protected void onResume() {
super.onResume();
callMainFragment();
}
private void callMainFragment() {
if (mSavedInstanceState == null) {
FragmentManager manager = getSupportFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
transaction.replace(R.id.container_category, new MainFragment(), MainFragment.class.getSimpleName());
transaction.addToBackStack(null);
transaction.commit();
}
}
public ActionBar getMainActionBar(){
ActionBar actionBar = getSupportActionBar();
if (actionBar != null) {
// Action Bar Display settings
actionBar.setDisplayShowCustomEnabled(true);
actionBar.setDisplayShowTitleEnabled(false);
// Custom view inflater
LayoutInflater inflater = (LayoutInflater) this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
// Custom layout view
View viewActionBar = inflater.inflate(R.layout.action_bar, null);
// Set custom view
actionBar.setCustomView(viewActionBar);
actionBar.setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM);
}
return actionBar;
}
This is my MainFragment:
public class MainFragment extends BaseFragment implements AdapterView.OnItemClickListener, BuyersGuideCategoriesDelegate, View.OnClickListener {
private Bundle mSavedInstanceState;
private BuyersGuideCategoriesFragment mCategoriesFragment;
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setRetainInstance(true);
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
mSavedInstanceState = savedInstanceState;
if (mSavedInstanceState == null) {
mView = inflater.inflate(R.layout.fragment_main, container, false);
// Call Grid View Buyers Guide Fragment
mCategoriesFragment = new BuyersGuideCategoriesFragment();
mCategoriesFragment.mGridViewDelegate = this;
setIcons();
setTitles();
setTexts();
initListView();
}
return mView;
}
#Override
public void onResume() {
super.onResume();
ImageView menu = (ImageView) ((MainActivity) getActivity()).getMainActionBar().getCustomView().findViewById(R.id.action_bar_menu_icon);
menu.setOnClickListener(this);
}
#Override
public void onClick(View v) {
if (mSavedInstanceState == null) {
MainActivity activity = (MainActivity) getActivity();
FragmentManager manager = activity.getSupportFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
transaction.replace(R.id.container_category, new MenuFragment(),MenuFragment.class.getSimpleName());
transaction.addToBackStack(null);
transaction.commit();
}
}
}
This is my MenuFragment:
public class MenuFragment extends BaseFragment implements AdapterView.OnItemClickListener, View.OnClickListener {
private Bundle mSavedInstanceState;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
mSavedInstanceState = savedInstanceState;
if (savedInstanceState == null) {
mView = inflater.inflate(R.layout.fragment_menu, container, false);
setMenuItemsListViewAdapter();
}
return mView;
}
private void setMenuItemsListViewAdapter() {
ListView menuItems = (ListView) mView.findViewById(R.id.list_menu_items);
ListMenuItemsListViewAdapter adapter = new ListMenuItemsListViewAdapter(getContext(),getMenuItemNames());
menuItems.setAdapter(adapter);
menuItems.setOnItemClickListener(this);
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
switch ((String) parent.getAdapter().getItem(position)){
case SIGN_UP:
replaceFragment(R.id.container_category,new SignUpFragment(),SignUpFragment.class.getSimpleName());
break;
}
}
private void replaceFragment(int containerId,Fragment fragment, String fragmentTag){
if (mSavedInstanceState == null){
MainActivity activity = (MainActivity) getActivity();
FragmentManager manager = activity.getSupportFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
transaction.replace(containerId,fragment,fragmentTag);
transaction.addToBackStack(null);
transaction.commit();
}
}
#Override
public void onClick(View v) {
switch (v.getId()){
case R.id.menu_back_icon:
replaceFragment(R.id.container_category, new MainFragment(),MainFragment.class.getSimpleName());
break;
}
}
}
And this is my SignUpFragment:
public class SignUpFragment extends BaseFragment implements View.OnClickListener{
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
if (savedInstanceState == null) {
mView = inflater.inflate(R.layout.fragment_sign_up, container, false);
}
return mView;
}
}
EDIT 1: The MainFragment is recreated only when I return from SignUpFragment to MenuFragment. I am doing wrong using so many fragments? Should I use activity?

When you are move between Fragments, call addToBackStack() :
FragmentTransaction ft = fragmentManager.beginTransation();
ft.replace( R.id.fragment, new MyFragment() ).addToBackStack( "ftransaction" ).commit();

Create first Fragment:
FragmentTransaction ft = fragmentManager.beginTransation();
ft.add(R.id.container, new FirstFragment()).addToBackStack(null).commit();
Second:
FragmentTransaction ft = fragmentManager.beginTransation();
ft.replace(R.id.container, new SecondFragment()).addToBackStack(null).commit();
and Third:
FragmentTransaction ft = fragmentManager.beginTransation();
ft.replace(R.id.container, new ThirdFragment()).commit();

How to come back on the start fragment from the 2_nd,3_rd fragments?

Here is my code
I need to go from A->B->C and onBackPressed() from B and C should go to A
while pressing back it goes to B and then to C , It seems to me that transaction.addToBackStack(null); not using as needed
public class TestfragmentActivity extends FragmentActivity{
private FrameLayout layout;
private String TAG = "TAG";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.test_fragment);
layout = (FrameLayout) findViewById(R.id.container);
A fragment = new A();
doFragmentTransaction(fragment, false);
}
private void doFragmentTransaction(Fragment fragment, boolean addToBackstack) {
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.add(R.id.container, fragment);
if (addToBackstack)
transaction.addToBackStack(TAG);
transaction.commit();
}
///////////////
public class A extends Fragment {
private Button button;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
final View view = inflater.inflate(R.layout.test_fragment1, null);
button = (Button) view.findViewById(R.id.button1);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
B fragment = new B();
doFragmentTransaction(fragment, true);
}
});
return view;
}
private void doFragmentTransaction(Fragment fragment, boolean addToBackstack) {
FragmentTransaction transaction = getActivity().getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.container, fragment);
if (addToBackstack) {
transaction.addToBackStack(null);
}
transaction.commit();
}
//////////////////////
public class B extends Fragment {
private Button button;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
final View view = inflater.inflate(R.layout.test_fragment2, null);
button = (Button) view.findViewById(R.id.button1);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
C fragment = new C();
doFragmentTransaction(fragment, false);
}
});
return view;
}
private void doFragmentTransaction(Fragment fragment, boolean addToBackstack) {
FragmentTransaction transaction = getActivity().getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.container, fragment);
if (addToBackstack)
transaction.addToBackStack(null);
transaction.commit();
}
}
}

in fragment B and C,
#Override
public void onBackPressed() {
}
in the function, replace the Container with Fragment A.