I have 3 tabs in my tabbed activity. I created 3 classes that extend Fragment and added my layouts. When I run it, it works fine. So I added some EditText widgets and a Button to my second tab. My question is : where do I put java code, for example, to handle onClickListener for that button.
I tried to do it in that main tabbed activity class but then the app crashed.
You can put that code in the relevant fragment of tabbed activity.
Application will crash because activity can not access the views which are inflated in fragment.
You can do like this :
public class PageFragment extends Fragment {
public static final String ARG_PAGE = "ARG_PAGE";
private int mPage;
public static PageFragment newInstance(int page) {
Bundle args = new Bundle();
args.putInt(ARG_PAGE, page);
PageFragment fragment = new PageFragment();
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mPage = getArguments().getInt(ARG_PAGE);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_page, container, false);
TextView textView = (TextView) view;
textView.setText("Fragment #" + mPage);
return view;
}
}
For more check this tutorial.
You must add button click code to respective Fragment i.e. second tab in your case. Don't write code on activity which host that fragment.
Related
I have a ListView in a Fragment that is populated when the app starts.
I put a ParcelableArrayList in a Bundle in my newInstance method, and I get it back in my OnCreateView after passing the ArrayList in the newInstance method in my Activity (which is the data read from the SQLite database).
This part works, as I display my data in my Fragment correctly.
I implemented a button that removes all data from the table, and I would now like to update my view after I cleaned the table.
The remove all button is handled in my main activity where I call my database handler to empty the table.
What is the best way to do that ? Here are the parts of the code that seem relevant to me :
My Fragment class :
public class MainFragment extends Fragment {
public static final String RECETTES_KEY = "recettes_key";
private List<Recette> mRecettes;
private ListView mListView;
public MainFragment() {
// Required empty public constructor
}
public static MainFragment newInstance(List<Recette> r) {
MainFragment fragment = new MainFragment();
Bundle bundle = new Bundle();
bundle.putParcelableArrayList(RECETTES_KEY, (ArrayList<? extends Parcelable>) r);
fragment.setArguments(bundle);
return fragment;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
mRecettes = getArguments().getParcelableArrayList(RECETTES_KEY);
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_main, container, false);
}
#Override
public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
configureListView();
}
// Configure ListView
private void configureListView(){
this.mListView = getView().findViewById(R.id.activity_main_list_view);
RecetteAdapter adapter = new RecetteAdapter(getContext(), mRecettes);
mListView.setAdapter(adapter);
}
}
Relevant parts from my Main acivity :
This is in my OnCreate method :
mDatabaseHandler = new DatabaseHandler(this);
mRecettes = mDatabaseHandler.readRecettes();
mDatabaseHandler.close();
This is in the method I use to show a fragment :
if (this.mMainFragment == null) this.mMainFragment = MainFragment.newInstance(mRecettes);
this.startTransactionFragment(this.mMainFragment);
Let me know if I should add more of my code, this is my first time posting :)
Lucile
In your R.layout.fragment_main, you can add an id to the root view, say with android:id#+id/fragment_root
And whenever you want to change the fragment view:
In activity:
MainFragment fragment = (MainFragment) getSupportFragmentManager().getFragmentById(R.id.fragment_root);
fragment.updateList(mRecettes);
And then create the new method updateList() in your MainFragment
public void updateList(List<Recette> recettes) {
mRecettes.clear();
mRecettes.addAll(recettes);
configureListView();
}
Also you can tag your fragment when you add it to your transaction instead of using its id, and then use getSupportFragmentManager().getFragmentByTag()
I have a couple of fragments. But all the fragments lead to PeriodFragment when they press a button. My question is how do I implement so that when the user presses the BACK button on his mobile phone, the PeriodFragment will switch back to the fragment it was entered from.
This is the java code from PeriodFragment.java:
public class PeriodFragment extends Fragment {
Button btnPretrazi;
public PeriodFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_period, container, false);
//buttonPretraziPeriod
btnPretrazi = (Button) view.findViewById(R.id.buttonPretraziPeriod);
btnPretrazi.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(getContext(),"test", Toast.LENGTH_SHORT).show();
}
});
return view;
}
}
This is my TvrdjavaFragment.java (one of the fragments that have the button to switch to PeriodFragment.java) :
package com.example.ivanp.msnis;
public class TvrdjavaFragment extends Fragment {
Button btnIdinaperiod;
public TvrdjavaFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_tvrdjava, container, false);
// Inflate the layout for this fragment
//show date
TextView datumprikaz = (TextView) view.findViewById(R.id.datumprikaz);
Date danas = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("dd.MM.yyyy");
String novDatum = sdf.format(danas);
datumprikaz.setText(novDatum);
//End of show date
btnIdinaperiod = (Button) view.findViewById(R.id.buttonIdinaperiod);
btnIdinaperiod.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
PeriodFragment periodFragment = new PeriodFragment();
FragmentTransaction periodFragmentTransaction = getActivity().getSupportFragmentManager().beginTransaction();
periodFragmentTransaction.replace(R.id.frame, periodFragment);
periodFragmentTransaction.commit();
}
});
return view;
}
}
I'm new to android studio, so please tell the details.
According to android docs When using fragments in your app, individual FragmentTransaction objects may represent context changes that should be added to the back stack. For example, if you are implementing a master/detail flow on a handset by swapping out fragments, you should ensure that pressing the Back button on a detail screen returns the user to the master screen. To do so, call addToBackStack() before you commit the transaction:
// Works with either the framework FragmentManager or the
// support package FragmentManager (getSupportFragmentManager).
getSupportFragmentManager().beginTransaction()
.add(detailFragment, "detail")
// Add this transaction to the back stack
.addToBackStack()
.commit();
Adding to backstack will solve the problem:
periodFragmentTransaction.replace(R.id.frame, periodFragment);
periodFragmentTransaction.addToBackStack(null);
periodFragmentTransaction.commit();
I have a main Activity in which I created a ViewPager that instantiate 3 other Fragments. One of these is a GridView which makes a popup appear when the user click on one item. Then, in this popup, I have a simple button.
What I want to do is: when the user click on this button, I would like to access a method in my main Activity (that should change the current item of my ViewPager) and then dismiss the popup.
I tried everything I could, but I cannot achieve this... I can set up the click event on my popup and dismiss it easily, but I didn't find out how I can access a method (or even a variable) from my popup to my main Activity.
I will put my most relevant code in here so you can understand the structure of my classes (hopefully...).
My main Activity:
public class MainActivity extends FirstActivity{
private ViewPager mViewPager;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mViewPager = (ViewPager) findViewById(R.id.viewpager);
// Set an Adapter on the ViewPager
mViewPager.setAdapter(new MainActivity_Adapter(getSupportFragmentManager()));
public void onSaveInstanceState(Bundle savedInstanceState)
{
menuBar.onSaveInstanceState(savedInstanceState);
}}
My ViewPager activity:
public class MainActivity_Adapter extends FragmentPagerAdapter{
public MainActivity_Adapter(FragmentManager fm)
{
super(fm);
}
#Override
public Fragment getItem(int position)
{
// Set the color background for each page
switch (position)
{
case 0:
return MainActivity_Inventory.newInstance();
case 1:
return MainActivity_Map.newInstance();
default:
return MainActivity_AR.newInstance();
}
}
// The number of Splash Screens to display
#Override
public int getCount()
{
return 3;
}}
My "Inventory" Fragment
public class MainActivity_Inventory extends Fragment implements View.OnClickListener{
public static MainActivity_Inventory newInstance()
{
MainActivity_Inventory frag = new MainActivity_Inventory();
Bundle b = new Bundle();
frag.setArguments(b);
return frag;
}
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
// Select the layout
int layout;
layout = R.layout.activity_inventory_01;
// Inflate the layout resource file
View view = getActivity().getLayoutInflater().inflate(layout, container, false);
// Set the grid view
GridView gridview = (GridView) view.findViewById(R.id.inventory_gridView);
gridview.setAdapter(new InventoryImageAdapter(super.getActivity()));
gridview.setOnItemClickListener(new AdapterView.OnItemClickListener()
{
public void onItemClick(AdapterView parent, View v, int position, long id)
{
// Create a popup to show item details
createPopup();
}
});
return view;
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState)
{
super.onViewCreated(view, savedInstanceState);
}
public void createPopup()
{
DialogFragment newFragment = new PopupActivity_Inventory();
newFragment.show(getFragmentManager(), "itemDetails");
}
#Override
public void onClick(View v)
{
}}
And my popup dialog fragment:
public class PopupActivity_Inventory extends DialogFragment{
#Override
public Dialog onCreateDialog(final Bundle savedInstanceState)
{
// Build the alert dialog
final Dialog dialog = new Dialog(this.getActivity());
// Get the layout inflater
final LayoutInflater inflater = getActivity().getLayoutInflater();
// Set up the dialog box
dialog.setContentView(inflater.inflate(R.layout.activity_inventory_popup_01, null));
dialog.getWindow().setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
dialog.getWindow().setGravity(Gravity.TOP);
//dialog.getWindow().getAttributes().y = 100;
(dialog.findViewById(R.id.brick_button_01)).setOnClickListener(new View.OnClickListener()
{
public void onClick(View view)
{
// When button is clicked, ACCESS MAIN ACTIVITY!
dialog.dismiss();
}
});
return dialog;
}}
I really hope you can help me with this... I really need to get it working. Thank you very much!
If you need further details or explanation, please just tell me.
The best thing to do is use EventBus library. I have a demo app in which you can add items to RecyclerView from anywhere within the app using EventBus. You can use it as a reference to simply do something else instead of current task. Here is the link to the repo:
https://github.com/code-crusher/android-demos/tree/master/EventBusDemo
And if you want to understand how it works you can refer to my article, it explains how to make communications like this easy:
https://medium.com/#code_crusher/eventbus-for-android
Hope it helps. Happy coding :)
Read this https://developer.android.com/training/basics/fragments/communicating.html
Look for "To allow a Fragment to communicate up to its Activity, you can define an interface in the Fragment class and implement it within the Activity...."
Another way to achieve it is using an EventBus and post events by Fragments to be caught by Activities.
i use fragment for my application,they are : Fragment A, Fragment B and Fragment C.
to move from one fragment to another fragment, I use two buttons, the first button is used to move to the next fragment, and the second button is used to return to the previous fragment.
the problems when I move from one fragment to another fragment (such as from A to B and back to A and to B again and to C). all entries in the EditText that is in a fragment is lost and look back empty,it when I go back to the previous fragment, or when I want to go back to the next fragment. I've been using code addToBackStack () when switching to another fragment, indeed EditText that I made not lost when I press the back button on my phone, but it does not affect the buttons (Next And Prev) that I've created. this is Fragment A:
public class AFragment extends Fragment {
EditText text,text2;
public AFragment(){}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_a, container, false);
ImageView next=(ImageView)rootView.findViewById(R.id.next);
text=(EditText)rootView.findViewById(R.id.text);
text2=(EditText)rootView.findViewById(R.id.text1);
next.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
getFragmentManager().beginTransaction().replace(R.id.frame_container, new BFragment()).addToBackStack(null).commit();
}
});
return rootView;
}
this is Fragment B:
public class BFragment extends Fragment {
EditText cut,cut2;
public BFragment(){}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View Fragment B = inflater.inflate(R.layout.fragment_c, container, false);
ImageView next=(ImageView)rootView.findViewById(R.id.next);
ImageView prev=(ImageView)rootView.findViewById(R.id.prev);
cut=(EditText)rootView.findViewById(R.id.cut);
cut2=(EditText)rootView.findViewById(R.id.cut2);
next.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
getFragmentManager().beginTransaction().replace(R.id.frame_container, new CFragment()).addToBackStack(null).commit();
}
});
prev.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
getFragmentManager().beginTransaction().replace(R.id.frame_container, new AFragment()).addToBackStack(null).commit();
}
});
return Fragment B;
}
my question is how can i save view in Fragment when user click on next and prev button in my application? is there something missing in my code? i hope someone can help me to solve my problem. thank you very much.
Each fragments have various life cycle methods, you can use onDestroy method and save the required edit text view value calling Activity. For this expose some methods in the calling activity which can be access via fragment. Also else create a singleton class or use Shared Prefences.
I hope this helps.
try to change:
getFragmentManager().beginTransaction().replace(R.id.frame_container, new BFragment()).addToBackStack(null).commit();
to:
getFragmentManager().beginTransaction().add(R.id.frame_container, new BFragment()).addToBackStack(null).commit();
I am trying to add left side slide menu inside my application but i am facing little trouble getting the slide menu to the following child activities of the fragment.
So far i have tried using this sliding menu example and when i got this image now inside the "Find People" fragment class i have static data.
Find People (Parent Activity) on Button Click go to ---> Friends (Child Activity of Find People) on Button Click go to ----> Names (Child Activity of Friends)
I am trying to get the same sliding menu with the Child Activities also that i failed to achieve so far please can any one help me out
public class FindPeopleFragment extends Fragment {
public FindPeopleFragment(){}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_find_people, container, false);
Button btn = (Button) rootView.findViewById(R.id.butto);
btn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(getActivity(), Friends.class);
startActivity(intent);
}
});
return rootView;
}
}
Friends (Child Activity)
public class Friends extends Activity {
Button btnNext;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.friends_xml);
btnNext = (Button)findViewById(R.id.btnNexts);
btnNext.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
// Go to Names Child Activity
}
});
}
}
And Similarly Names (Child Activity)
How do i get the same slide menu in both the child activities (Friends & Names). Any idea ??
Plz help me out in this.
Code Snippet will be much helpful.
Thanks
As #Piyush Gupta said you need to call new Fragment instead of calling activities,
In Place of activity you need to use Fragment and move from one Fragment to next used this code
Instead of using Fragment element use Framelayout id of the fragment Xml
Replace ur code with this
public class FindPeopleFragment extends Fragment {
public FindPeopleFragment(){}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_find_people, container, false);
Button btn = (Button) rootView.findViewById(R.id.butto);
btn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
FragementDemo fd = new FragementDemo();
android.support.v4.app.FragmentTransaction ft =
getFragmentManager().beginTransaction();
ft.replace(R.id.content_frame, fd); // content_frame is your FrameLayout container
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
ft.addToBackStack(null);
ft.commit();
}
});
return rootView;
}
}
And your next child activity will extend Fragment not Activity like this :
public class Friends extends SherlockFragment{
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragementdemo, container, false);
// use button click code as used in FindPeopleFragment
return rootView;
}
}
Hope it works fine now for you!!