Le texte ne s'affiche pas sur ViewPager

Question

Je rencontre un problème lorsque mon texte ViewPager ne s'affiche pas lorsque je démarre mon application. Cependant, les textes finissent par montrer quand je glisse l'onglet. Je ne suis pas sûr du problème et j'aimerais que le texte apparaisse dès que ma demande commence. Toute aide serait appréciée! Merci.

activité Pays (activité principale)

package myapps.countryapp; 

import android.content.Context; 
import android.support.v4.app.Fragment; 
import android.support.v4.app.FragmentManager; 
import android.support.v4.app.FragmentPagerAdapter; 
import android.support.v4.view.ViewPager; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import static myapps.countryapp.R.id.pager; 

public class CountriesActivity extends AppCompatActivity { 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_countries); 

    ViewPager viewPager = (ViewPager) findViewById(pager); 
    viewPager.setAdapter(new MyAdapter(getSupportFragmentManager())); 
} 

public class MyAdapter extends FragmentPagerAdapter { 
    final int PAGE_COUNT = 2; 
    //Create tab tiles. 
    private String tabTiles[] = new String[] {"Countries", "Map"}; 
    Context context; 

    public MyAdapter(FragmentManager fm) { 
     super(fm); 
    } 

    @Override 
    public Fragment getItem(int position) { 
     if(position == 0){ 
      Fragment fragmentList = new Countries(); 
      return fragmentList; 
     }else { 
      Countries fragmentList = new Countries(); 
      return fragmentList; 
     } 
    } 

    @Override 
    public int getCount() { 
     return PAGE_COUNT; 
    } 

    @Override 
    public CharSequence getPageTitle(int position) { 
     return tabTiles[position]; 
    } 
    } 

}//end of class 

Countries.java (fichier fragment)

package myapps.countryapp; 

import android.os.Bundle; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.support.v4.app.Fragment; 


/** 
* A simple {@link Fragment} subclass. 
*/ 
public class Countries extends Fragment { 


public Countries() { 
    // 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_countries, container, false); 
    return view; 
} 

} 

activity_countries (XML PRINCIPAL FICHIER)

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" 
android:layout_height="fill_parent" android:paddingLeft="@dimen/activity_horizontal_margin" 
android:paddingRight="@dimen/activity_horizontal_margin" 
android:paddingTop="@dimen/activity_vertical_margin" 
android:paddingBottom="@dimen/activity_vertical_margin" 
tools:context="myapps.countryapp.CountriesActivity"> 

<android.support.v4.view.ViewPager 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    android:id = "@+id/pager" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent"> 

<android.support.v4.view.PagerTabStrip 
    android:layout_width="match_parent" 
    android:layout_height = "40dp" 
    android:paddingTop = "4dp" 
    android:paddingBottom = "10dp" 
    android:layout_gravity = "top" 
    android:id = "@+id/pagerStrip"> 

</android.support.v4.view.PagerTabStrip> 

</android.support.v4.view.ViewPager> 

fragment_countries.xml

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" 
android:layout_height="match_parent" tools:context="myapps.countryapp.Countries"> 

<!-- TODO: Update blank fragment layout --> 


<ListView 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:id="@+id/MyListView"> 
    </ListView> 

</FrameLayout> 

Answer 1

Ok, voici mon exemple d'activité, viewpager et fragment:

activité:

public class KataloziSlike extends AppCompatActivity { 


    private AdapterCustomPage mAdapterCustomPage; 
    private ViewPager mViewPager; 
    private TextView tv, brojStranica; 
    private ImageButton settings, share, locirajMe, back; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_katalozi_slike); 

     if (Static.katalozi.getSlikeKataloga().size() == 1) { 
      Message.message(KataloziSlike.this, "Katalog ima samo jednu stranu"); 
     } 
     brojStranica = (TextView) findViewById(R.id.tvBrojStranicaKataloga); 
     brojStranica.setText(String.valueOf(1) + "/" + String.valueOf(Static.katalozi.getSlikeKataloga().size() + 1)); 

     mAdapterCustomPage = new AdapterCustomPage(getFragmentManager(), this); 
     mViewPager = (ViewPager) findViewById(R.id.view_pagerZaSlikeKataloga); 
     mViewPager.setAdapter(mAdapterCustomPage); 
     mViewPager.setCurrentItem(0); 


     mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() { 
      @Override 
      public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { 

      } 

      @Override 
      public void onPageSelected(int position) { 

       if (Static.katalozi.getSlikeKataloga().size() != 1) { 
        if (position == 0) { 
         Message.message(KataloziSlike.this, "Na prvoj stranici kataloga ste"); 
        } else if (position == Static.katalozi.getSlikeKataloga().size() - 1) { 
         Message.message(KataloziSlike.this, "Na poslednjoj stranici kataloga ste"); 
        } 
       } 

       if (position <= Static.katalozi.getSlikeKataloga().size() - 1) { 
        YourFragmentInterface fragment = (YourFragmentInterface) mAdapterCustomPage.instantiateItem(mViewPager, position); 
        if (fragment != null) { 
         fragment.fragmentBecameVisible(); 
        } 
       } 

       brojStranica.setText(String.valueOf(position + 1) + "/" + String.valueOf(Static.katalozi.getSlikeKataloga().size() + 1)); 
      } 

      @Override 
      public void onPageScrollStateChanged(int state) { 

      } 
     }); 
} 
} 

adaptateur

:

public class AdapterCustomPage extends FragmentStatePagerAdapter { 

    protected Context mContext; 
    int maxBrojStrana = Static.katalozi.getSlikeKataloga().size(); 
    int pozicija; 
    private ArrayList<Katalozi> mKatalozi; 

    public AdapterCustomPage(FragmentManager fm, Context context) { 
     super(fm); 
     mContext = context; 
    } 




    @Override 
    public Fragment getItem(int position) { 

     // Create fragment object 
     if (position == maxBrojStrana) { 
      Fragment fragment = new ImageFragmentMapKatalozi(); 
      return fragment; 
     } else { 
      Fragment fragment = new ImageFragmentKatalozi(); 
      fragment.onPause(); 
      Bundle args = new Bundle(); 
      Log.i("Poizicija", String.valueOf(position)); 
      String url = Static.katalozi.getSlikeKataloga().get(position); 
      args.putString("url", url); 

      fragment.setArguments(args); 


      String link = Static.katalozi.getUrl(); 
      args.putString("linkKataloga", link); 




      return fragment; 
     } 

    } 


    @Override 
    public int getItemPosition(Object object) { 
     pozicija = super.getItemPosition(object); 
     return super.getItemPosition(object); 
    } 

    @Override 
    public int getCount() { 
     return maxBrojStrana + 1; 
    } 

} 

et fragment:

public class ImageFragmentKatalozi extends Fragment implements KataloziSlike.YourFragmentInterface { 


    private PhotoViewAttacher mAttacher; 
    private ImageView imageView; 
    private Bundle args; 
    private Button button; 

    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 

     View rootView = inflater.inflate(R.layout.fragment_katalozi_slike, container, false); 

     args = getArguments(); 
     imageView = (ImageView) rootView.findViewById(R.id.imageViewAdapterZaListanjeKataloga); 


     Callback imageLoadedCallback = new Callback() { 

      @Override 
      public void onSuccess() { 
       if (mAttacher != null) { 
        mAttacher.update(); 
       } else { 
        mAttacher = new PhotoViewAttacher(imageView); 

       } 
      } 

      @Override 
      public void onError() { 
       // TODO Auto-generated method stub 

      } 
     }; 

     Picasso.with(getActivity()).load(args.getString("url")).placeholder(R.drawable.load).error(R.drawable.error).into(imageView, imageLoadedCallback); 
     mAttacher = new PhotoViewAttacher(imageView); 
     button = (Button) rootView.findViewById(R.id.zaProveru); 
     button.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 

      } 
     }); 


     return rootView; 
    } 


    @Override 
    public void onResume() { 
     super.onResume(); 
     Toast.makeText(getActivity(), "sadsadasd", Toast.LENGTH_SHORT); 
    } 


    @Override 
    public void fragmentBecameVisible() { 
     mAttacher.update(); 
    } 
} 

Quel est le problème avec le vôtre est qu'il isnt instatiated quand premier fragment est fait, que lorsque vous balayez (sur le changement fragment), puis sa projection. Revenir à mon exemple