Ajouter / Supprimer des pages à ViewPager dynamiquement

Oui, depuis ViewPager devient l'enfant du point de Vue d'une PagerAdapter, vous pouvez ajouter de nouvelles pages /supprimer des pages, et d'appel .notifyDataSetChanged() pour le recharger.

Oui, le code devrait ressembler à ceci:

public int addPage(View view, int position) {
        if ((position >= 0) && (position < getSize())) {
            myPagerAdapter.mListViews.add(position, view);
            myPagerAdapter.notifyDataSetChanged();
            return position;
        } else {
            return -1;
        }
    }

public View removePage(int position) {
        if ((position < 0) || (position >= getSize()) || (getSize()<=1)) {
            return null;
        } else {
            if (position == mPager.getCurrentItem()) {
                if(position == (getSize()-1)) {
                    mPager.setCurrentItem(position-1);
                } else if (position == 0){
                    mPager.setCurrentItem(1);
                }
            }
            View tempView = myPagerAdapter.mListViews.remove(position);
            myPagerAdapter.notifyDataSetChanged();
            return tempView;
        }
    }

Mais il y a un bug. Si l'Élément courant est 0, et de supprimer la page 0, il ne sera pas de rafraîchissement de l'écran instantanément, je n'ai pas trouvé une solution pour cela.

Voici une solution alternative à cette question. Ma carte:

private class PagerAdapter extends FragmentPagerAdapter implements 
ViewPager.OnPageChangeListener, TabListener {
private List<Fragment> mFragments = new ArrayList<Fragment>();
private ViewPager mPager;
private ActionBar mActionBar;
private Fragment mPrimaryItem;
public PagerAdapter(FragmentManager fm, ViewPager vp, ActionBar ab) {
super(fm);
mPager = vp;
mPager.setAdapter(this);
mPager.setOnPageChangeListener(this);
mActionBar = ab;
}
public void addTab(PartListFragment frag) {
mFragments.add(frag);
mActionBar.addTab(mActionBar.newTab().setTabListener(this).
setText(frag.getPartCategory()));
}
@Override
public Fragment getItem(int position) {
return mFragments.get(position);
}
@Override
public int getCount() {
return mFragments.size();
}
/** (non-Javadoc)
* @see android.support.v4.app.FragmentStatePagerAdapter#setPrimaryItem(android.view.ViewGroup, int, java.lang.Object)
*/
@Override
public void setPrimaryItem(ViewGroup container, int position,
Object object) {
super.setPrimaryItem(container, position, object);
mPrimaryItem = (Fragment) object;
}
/** (non-Javadoc)
* @see android.support.v4.view.PagerAdapter#getItemPosition(java.lang.Object)
*/
@Override
public int getItemPosition(Object object) {
if (object == mPrimaryItem) {
return POSITION_UNCHANGED;
}
return POSITION_NONE;
}
@Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
mPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) { }
@Override
public void onTabReselected(Tab tab, FragmentTransaction ft) { }
@Override
public void onPageScrollStateChanged(int arg0) { }
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) { }
@Override
public void onPageSelected(int position) {
mActionBar.setSelectedNavigationItem(position);
}
/**
* This method removes the pages from ViewPager
*/
public void removePages() {
mActionBar.removeAllTabs();
//call to ViewPage to remove the pages
vp.removeAllViews();
mFragments.clear();
//make this to update the pager
vp.setAdapter(null);
vp.setAdapter(pagerAdapter);
}
}

Code pour supprimer et ajouter dynamiquement

//remove the pages. basically call to method removeAllViews from ViewPager
pagerAdapter.removePages();
pagerAdapter.addPage(pass your fragment);

Après les conseils de Péri Hartman, il a commencé à travailler, après j'ai mis null à ViewPager de l'adaptateur et de mettre la carte à nouveau après le point de vue supprimé. Avant cela, la page 0 n'a pas montré son contenu de la liste.

@Bind(R.id.pager)
ViewPager pager;
int pos = pager.getCurrentItem();
pager.removeViewAt(pos);

Sur la base d'autres réponses et d'autres ressources que j'ai terminé avec ce code.

CustomPagerAdapter:

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.view.PagerAdapter;
import android.view.View;
import android.view.ViewGroup;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class CustomPagerAdapter extends PagerAdapter {
private List<Fragment> pages = new ArrayList<>();
private Map<Fragment, Integer> fragmentsPosition = new HashMap<>();
private Fragment currentPrimaryItem;
private FragmentManager fragmentManager;
private FragmentTransaction currentTransaction;
public CustomPagerAdapter(FragmentManager fragmentManager) {
this.fragmentManager = fragmentManager;
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
if (currentTransaction == null) {
currentTransaction = fragmentManager.beginTransaction();
}
Fragment pageFragment = pages.get(position);
String tag = pageFragment.getArguments().getString(MainActivity.FRAGMENT_TAG_ARG);
Fragment fragment = fragmentManager.findFragmentByTag(tag);
if (fragment != null) {
if (fragment.getId() == container.getId()) {
currentTransaction.attach(fragment);
}
else {
fragmentManager.beginTransaction().remove(fragment).commit();
fragmentManager.executePendingTransactions();
currentTransaction.add(container.getId(), fragment, tag);
}
}
else {
fragment = pageFragment;
currentTransaction.add(container.getId(), fragment, tag);
}
if (fragment != currentPrimaryItem) {
fragment.setMenuVisibility(false);
fragment.setUserVisibleHint(false);
}
return fragment;
}
@Override
public int getCount() {
return pages.size();
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
if (currentTransaction == null) {
currentTransaction = fragmentManager.beginTransaction();
}
currentTransaction.detach((Fragment) object);
}
@Override
public void setPrimaryItem(ViewGroup container, int position, Object object) {
Fragment fragment = (Fragment) object;
if (fragment != currentPrimaryItem) {
if (currentPrimaryItem != null) {
currentPrimaryItem.setMenuVisibility(false);
currentPrimaryItem.setUserVisibleHint(false);
}
if (fragment != null) {
fragment.setMenuVisibility(true);
fragment.setUserVisibleHint(true);
}
currentPrimaryItem = fragment;
}
}
@Override
public void finishUpdate(ViewGroup container) {
if (currentTransaction != null) {
currentTransaction.commitAllowingStateLoss();
currentTransaction = null;
fragmentManager.executePendingTransactions();
}
}
@Override
public boolean isViewFromObject(View view, Object object) {
return ((Fragment) object).getView() == view;
}
@Override
public int getItemPosition(Object o) {
Integer result = fragmentsPosition.get(o);
if (result == null) {
return PagerAdapter.POSITION_UNCHANGED;
}
return result;
}
//---------------------------------- Page actions ----------------------------------
public void addPage(Fragment fragment) {
fragmentsPosition.clear();
pages.add(fragment);
notifyDataSetChanged();
}
public void removePage(int position) {
fragmentsPosition.clear();
Fragment pageFragment = pages.get(position);
String tag = pageFragment.getArguments().getString(MainActivity.FRAGMENT_TAG_ARG);
Fragment fragment = fragmentManager.findFragmentByTag(tag);
if (fragment != null) {
fragmentsPosition.put(fragment, PagerAdapter.POSITION_NONE);
}
for (int i = position + 1; i < pages.size(); i++) {
pageFragment = pages.get(i);
tag = pageFragment.getArguments().getString(MainActivity.FRAGMENT_TAG_ARG);
fragment = fragmentManager.findFragmentByTag(tag);
if (fragment != null) {
fragmentsPosition.put(fragment, i - 1);
}
}
pages.remove(position);
notifyDataSetChanged();
}
}

MainActivity:

import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
public class MainActivity extends AppCompatActivity {
public static final String FRAGMENT_TAG_ARG = "tag";
private CustomPagerAdapter mCustomPagerAdapter;
private ViewPager mViewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mCustomPagerAdapter = new CustomPagerAdapter(getSupportFragmentManager());
mCustomPagerAdapter.addPage(MainFragment.newInstance("Main_Title"));
mCustomPagerAdapter.addPage(SecondaryFragment.newInstance("Secondary_Title"));
mViewPager = (ViewPager) findViewById(R.id.container);
mViewPager.setAdapter(mCustomPagerAdapter);
}
}

De supprimer les pages:

mCustomPagerAdapter.removePage(1);

MainFragment:

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class MainFragment extends Fragment {
public static final String FRAGMENT_TAG = "MainFragment";
public static MainFragment newInstance(String text) {
return newInstance(text, FRAGMENT_TAG);
}
public static MainFragment newInstance(String text, String tag) {
MainFragment fragment = new MainFragment();
Bundle args = new Bundle();
args.putString("text", text);
args.putString(MainActivity.FRAGMENT_TAG_ARG, tag + "_" + fragment.hashCode());
fragment.setArguments(args);
return fragment;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
TextView textView = (TextView) rootView.findViewById(R.id.section_label);
textView.setText(getArguments().getString("text"));
return rootView;
}
}

SecondaryFragment a le même code.

Les modèles sont simples ViewPager/Fragment de mises en page avec android.support.v4.view.ViewPager avec l'id container et le Fragment TextView avec l'id section_label.

Ressources:

• ajouter et supprimer dynamiquement vue de viewpager
• Comment faire pour Supprimer Fragment de FragmentPagerAdapter?
• https://github.com/takaaki7/ArrayPagerAdapter
• https://github.com/commonsguy/cwac-pager