Develop Reference

How to show fragment only when button pressed?

I'm trying to show an image below a button only after the button has been pressed. My problem is that the fragment is shown immediately when the app is started and not only after the button has been pressed.
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void say_hello(View view){
Fragment fragment = new ExampleFragment();
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.fragment2, fragment).commit();
}
}
public class ExampleFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.news_articles, container, false);
}
}
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:tools="http://schemas.android.com/tools"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:orientation="vertical"
android:layout_height="fill_parent"
tools:context=".MainActivity">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal|center_vertical"
android:text="PRESS THIS"
android:id = "#+id/test_button"
android:background="#drawable/test_button"
android:onClick="say_hello"
/>
<fragment
android:id="#+id/fragment2"
android:name="com.example.tic_tac_toe.ExampleFragment"
android:layout_width="match_parent"
android:layout_height="643dp" />
</LinearLayout>
<ImageView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:src="#drawable/cool_dog">
</ImageView>
I'm guessing the fragment shows up when the app is started because of the name I give to the fragment in the XML, but the fragment needs a name otherwise I only get error. How do I get the fragment to display nothing before I have clicked the button?

Instead of using <fragment /> view in your xml, you can use Framelayout and add your fragment to this Framelayout on button click using the following code -
FragmentTransaction transaction = getFragmentManager().beginTransaction();
transaction.add(R.id.mainframe, fragment);
transaction.commit();
Where mainframe is the id of Framelayout.

You can try doing this
android.app.Fragment fragment = getActivity().getFragmentManager().findFragmentByTag("YOUR_FRAGMENT_TAG");
getActivity().getFragmentManager().beginTransaction().hide(fragment);
inside your click event.

fragments overlap in one screen

I am now practicing on ViewPager and Fragments but I am facing an issue with replacing fragment to one another.
It is working well with swiping screen to move to another fragment, but I also wanted to try out if I can do this with a button too.
So I added a button, and tried to use FragmentManager's replace() method.
But what it actually does is not replacing the fragment but adding the fragment on the current fragment.
In a simple word, it overlaps.
Could not really find anything helpful for hours now, can anyone please help me with it?
Here is my code of the fragment that has the button:
public class MainActivity extends Fragment {
Fragment fragment;
FragmentManager fragmentManager;
FragmentTransaction fragmentTransaction;
Button buildButton;
private ViewPager viewPager;
public static Fragment newInstance(Context context) {
MainActivity mainActivity = new MainActivity();
return mainActivity;
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, Bundle savedInstanceState) {
ViewGroup root = (ViewGroup) inflater.inflate(R.layout.main, null);
return root;
}
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
buildButton = (Button) getView().findViewById(R.id.buildButton);
buildButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
fragment = new SecondActivity();
fragmentManager = getActivity().getSupportFragmentManager();
fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.calendarActivity, fragment);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
}
});
}
}
And this is the xml file of the fragment:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<fragment class="com.example.auclo.calendarpractice5.MainActivity"
android:id="#+id/calendarActivity"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
<Button
android:id="#+id/buildButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="100dp"
android:layout_marginEnd="148dp"
android:layout_marginStart="148dp"
android:layout_marginTop="16dp"
android:text="Track"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/calendarView" />
</android.support.constraint.ConstraintLayout>
And this is the fragment that I want to replace to:
public class SecondActivity extends Fragment {
TextView textView;
public static Fragment newInstance(Context context) {
SecondActivity secondActivity = new SecondActivity();
return secondActivity;
}
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
ViewGroup root = (ViewGroup) inflater.inflate(R.layout.activity_second, null);
return root;
}
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
textView = getView().findViewById(R.id.textView);
}
}
And xml of the second fragment:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".SecondActivity">
<fragment class="com.example.auclo.calendarpractice5.SecondActivity"
android:id="#+id/secondActivity"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Pikachu"
android:textSize="18sp" />
</RelativeLayout>
I will really appreciate to any kind of help.
Thank you!

The issue is that you're replacing the element with ID calendarActivity with your new fragment. This element is inside the XML for your first fragment (I think, based on your post). So it's putting this fragment in your old fragment.
You'll need to instead use the id in R.layout.main that represents your first fragment. I usually use a framelayout for this. Then I have the activity replace that framelayout with a fragment in its onCreate().

To add the same visual effects, you have to add a animation to your fragmentTransaction
Exemple:
fragmentTransaction.setCuston(
R.anim.enter_from_right,
R.anim.exit_to_left);
See this answer for explanation on fragments animations

how to call fragment from another fragment in tablayout with viewpager

I want to call a fragment on button click which is a fragment. I tried this code but it's not working. with this code when I click on the button it shows next fragment but not its designing. I see only a blank page.
This is my main xml :-
<LinearLayout
android:id="#+id/main_layout"
android:orientation="vertical"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<!-- our toolbar -->
<!-- our tablayout to display tabs -->
<android.support.design.widget.TabLayout
android:id="#+id/tabLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabMode="scrollable"
app:tabGravity="fill"
android:background="#fa4022"
android:minHeight="?attr/actionBarSize"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"/>
<!-- View pager to swipe views -->
<android.support.v4.view.ViewPager
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="fill_parent"/>
I have an dashboard tab in this TabLayout. In this dashboard tab i have an button which id is userprofile. after click on this button i want to go on user_profile.xml
public class Dashboard extends Fragment implements View.OnClickListener {
Button userprofile;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.dashboard, container, false);
userprofile=(Button)rootView.findViewById(R.id.userprofile);
userprofile.setOnClickListener(this);
return rootView;
}
#Override
public void onClick(View view) {
Fragment fragment = null;
switch (view.getId()) {
case R.id.userprofile:
fragment = new User_Profile();
replaceFragment(fragment);
break;
}
}
private void replaceFragment(Fragment fragment) {
User_Profile user_profile = new User_Profile();
FragmentTransaction transaction = getFragmentManager().beginTransaction();
transaction.replace(R.id.pager, fragment);
transaction.addToBackStack(null);
transaction.commit();
}
User_Profile class code is :-
public class User_Profile extends Fragment {
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View rooView=inflater.inflate(R.layout.user_profile, container, false);
return rooView;
}
}
user_profile.xml is :-
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="User Profile"
android:textSize="30dp"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"/>

If you can see fragment on button click but not designing then its may error in your fragment .xml file. By using proper view problem can be solve. If there is also a problem with same post their .xml file code.

Can you show us some more data please? What's the XML for the pager fragment you're trying to replace the current fragment with?
Could you check that you're referring to the layout of that XML file, and not the individual pager element too?
(Since transaction.replace requires a fragment container as it's first argument)

How to create multiple fragments programmatically?

I am trying to show multiple fragments on the one screen by creating them programmatically. I am able to do this no problem by including each fragment into the activities layout file. However when I try and do it programmatically Im confused.This is what I have so far for two fragments on a screen.
Main Class:
public class MainActivity extends FragmentActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FragmentOne one = new FragmentOne();
FragmentTwo two = new FragmentTwo();
FragmentThree three = new FragmentThree();
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.add(R.id.imOne, one, "fragmentone");
ft.add(R.id.imTwo, two, "fragmenttwo");
ft.add(R.id.imThree, three, "fragmenthree");
ft.commit();
}
}
Fragment One:
public class FragmentOne extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// TODO Auto-generated method stub
View view = inflater.inflate(R.layout.frag_one, container, false);
return view;
}
}
Fragment Two:
public class FragmentTwo extends Fragment{
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// TODO Auto-generated method stub
View view = inflater.inflate(R.layout.frag_two, container, false);
return view;
}
}
The layout files for my two fragment classes just contain a simple TextView.
And then the activity_main.xml layout file for my main class:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >
<FrameLayout
android:id="#+id/imOne"
android:name="com.david.twofragexample.FragmentOne"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="2" />
<FrameLayout
android:id="#+id/imTwo"
android:name="com.david.twofragexample.FragmentTwo"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="2" />
<FrameLayout
android:id="#+id/imThree"
android:name="com.david.twofragexample.FragmentThree"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="2" />
</LinearLayout>
When I try and do it programatically I get confused as to what should be in my activity_main.xml file. So from the Android Developer Guide(http://developer.android.com/guide/components/fragments.html) it says to use
FragmentManager fragmentManager = getFragmentManager()
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
FragmentOne fragment = new FragmentOne();
fragmentTransaction.add(R.id.fragment_container, fragment);
fragmentTransaction.commit();
So when I add this code to my onCreate method what changes do I have to make to my activity_main.xml file to do this programmatically?I don't see where R.id.fragment_container comes from. How can I determine where on the screen my new fragment will go?Thanks
EDIT: I am developing this on a tablet and not a phone.This has now been solved and the above code will add three fragments programmatically.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >
<FrameLayout
android:id="#+id/list"
android:name="com.david.twofragexample.FragmentOne"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="2" />
<FrameLayout
android:id="#+id/viewer"
android:name="com.david.twofragexample.FragmentTwo"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="2" />
</LinearLayout>
In your Activity:
FragmentOne one = new FragmentOne();
FragmentTwo two = new FragmentTwo();
fm = getSupportFragmentManager();
fm.beginTransaction().replace(R.id.list, one, "fragmentone").commit();
fm.beginTransaction().replace(R.id.viewer, two, "fragmenttwo").commit();
I suggest you study this:
http://developer.android.com/reference/android/app/Fragment.html
and fully understand the fragment lifecycle, etc. The way I show is quick and dirty, but not neccesarilly best.

As I don't have higher enough reps to comment yet, I will just leave the information here -- the way Rafael T suggested does work nicely, although I also had my doubt at the first place.
1) Define your xml like this:
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
>
2) Add each fragment into the same slot:
View box = v.findViewById(R.id.container);
FragmentTransaction ft = getFragmentManager().beginTransaction();
for (String catalog : mCatalogs) {
Fragment fragment = HighlightedProductFragment.newInstance(catalog);
ft.add(R.id.container, fragment, catalog);
}
ft.commit();
Thanks for the solution for this tricky requirement.

Try it like this:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
as your activity_main.xml
You asked yourself the right question: where is the id fragment_container, and the answer was: nowhere. >ou also set your layout to horizontal, which makes it very likely, that added Views will be kind of 'out of screen'

ActionbarSherlock Fragment in Fragment

I don't know it's a problem of my application structure or a problem with my code.
I have a tabActivity which extends SherlockFragmentActivity.
This has a ViewPager and a TabsAdapter.
There are two Tabs and one OptionsMenu item ("search").
The two tabs are for entering search parameters. One simple, one detaild. If search is clicked, a search is performed and the results shall be shown.
The content of the tabs are already objects of the type SherlockFragment. So far, this works fine.
At the moment, the search results are a seperate activity. I would like to have them in the viewpager as well. So I converted it to a SherlockActivity. But if I make ("this" is the tabActivity) in the onCreate() Method:
FragmentManager fm = this.getSupportFragmentManager();
Fragment ft = Fragment.instantiate(this, searchFragment.class.getName(), null);
if(fm.findFragmentById(R.id.searchresults_content) == null)
{
fm.beginTransaction().add(R.id.searchresults_content, ft).commit();
}
and then:
this.mViewPager.addView(ft.getView());
but ft.getView(); returns null. OnCreateView from searchFragment will do this:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
WebView mWebView = (WebView)findViewById(R.id.search_results);
View mView = inflater.inflate(R.layout.search_results, container, false);
mWebView.setWebViewClient(new SearchResultsWebViewClient());
//... (load data for webview etc...)
return mView;
}
search_results.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<WebView xmlns:android="http://schemas.android.com/apk/res/android"
android:id ="#+id/search_results"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</WebView>
</LinearLayout>