android - studio - Fragmento no muestra el contenido de TabHost en la segunda vez

tabs con fragments android

Question

Bueno ... estoy trabajando con fragmentos, android.support.v4.widget.DrawerLayout, TabHost y ViewPager ... Tengo el siguiente código:

main_base.xml

<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<FrameLayout
android:id="@+id/content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<ListView
android:id="@+id/listado_pintado"
android:layout_width="240dp"
android:layout_height="match_parent"
android:layout_gravity="start"
android:choiceMode="singleChoice"
android:divider="@android:color/transparent"
android:dividerHeight="0dp"
android:background="#fff"/>

mi actividad:

Actividad principal

package com.examples.planets;
import android.annotation.SuppressLint;
import android.app.Fragment;
import android.app.FragmentManager;
import android.content.Context;
import android.content.res.Configuration;
import android.os.Bundle;
import android.support.v4.app.ActionBarDrawerToggle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.GravityCompat;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.widget.DrawerLayout;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TabHost;
import com.examples.planets.TabsFragmentos;
import com.examples.planets.fragmentos.mercury.TabFragmentDescribeMercury;
import com.examples.planets.fragmentos.mercury.TabFragmentShowMercury;
import com.examples.planets.paginadores.AdaptadorDePaginas;
import com.examples.planets.utilidades.enums.Menu_;
import java.util.HashMap;
import java.util.List;
import java.util.Vector;
public class Main_Activity extends FragmentActivity{
public DrawerLayout mDrawerLayout;
private ListView mDrawerList;
private ActionBarDrawerToggle mAccionadorDelDrawer;
private CharSequence mDrawerTitulo;
private CharSequence mTitulo;
private String[] menuPrincipal;
public void cargarMenu(){
//Titulo
mTitulo = mDrawerTitulo = getTitle();
//Main_Activity Principal
menuPrincipal = getResources().getStringArray(R.array.menu_principal_array);
//Diseñador del Layout
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
mDrawerList = (ListView) findViewById(R.id.listado_pintado);
mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);
mDrawerList.setAdapter(new ArrayAdapter<String>(this,
R.layout.menu_listado, menuPrincipal));
mDrawerList.setOnItemClickListener(new DrawerItemClickListener());
getActionBar().setDisplayHomeAsUpEnabled(true);
getActionBar().setHomeButtonEnabled(true);
mAccionadorDelDrawer = new ActionBarDrawerToggle(
this, /* host Activity */
mDrawerLayout, /* DrawerLayout object */
R.drawable.ic_drawer, /* Imagen del Accionador del menu */
R.string.drawer_open, /* "open drawer" description for accessibility */
R.string.drawer_close /* "close drawer" description for accessibility */
) {
public void onDrawerClosed(View view) {
getActionBar().setTitle(mTitulo);
invalidateOptionsMenu();
}
public void onDrawerOpened(View drawerView) {
getActionBar().setTitle(mDrawerTitulo);
invalidateOptionsMenu();
}
};
mDrawerLayout.setDrawerListener(mAccionadorDelDrawer);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.menu_base);
cargarMenu();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
//inflater.inflate(R.menu.main, menu);
return super.onCreateOptionsMenu(menu);
}
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
// If the nav drawer is open, hide action items related to the content view
boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
//menu.findItem(R.id.action_websearch).setVisible(!drawerOpen);
return super.onPrepareOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (mAccionadorDelDrawer.onOptionsItemSelected(item)) {
return true;
}
return super.onOptionsItemSelected(item);
}
private class DrawerItemClickListener implements ListView.OnItemClickListener {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
selectItem(position);
}
}
private void selectItem(int position) {
android.support.v4.app.FragmentManager manager = super.getSupportFragmentManager();
TabsFragmentos firstFragment = new TabsFragmentos(position, this, super.getSupportFragmentManager());
manager.beginTransaction()
.replace(R.id.content_frame, firstFragment).commit();
mDrawerList.setItemChecked(position, true);
setTitle(menuPrincipal[position]);
mDrawerLayout.closeDrawer(mDrawerList);
//cargarMenu();
}
@Override
public void setTitle(CharSequence title) {
mTitulo = title;
getActionBar().setTitle(mTitulo);
}
/**
* Cuando usamos el ActionBarDrawerToggle, se debería llamar este durante el
* onPostCreate() y el onConfigurationChanged()...
*/
@Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
onRestoreInstanceState.
mAccionadorDelDrawer.syncState();
}
@Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
mAccionadorDelDrawer.onConfigurationChanged(newConfig);
}
}

Y el TabFragments es Fragmento:

package com.examples.planets.fragmentos;
import java.util.HashMap;
import java.util.List;
import java.util.Vector;
import android.annotation.SuppressLint;
import android.content.Context;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TabHost;
import android.widget.TabHost.TabContentFactory;
....
/**
* @author roldan
*
*/
@SuppressLint("ValidFragment")
public class TabsFragmentos extends Fragment implements TabHost.OnTabChangeListener, ViewPager.OnPageChangeListener {
private TabHost mTabHost;
private HashMap<String, TabInfo> mapTabInfo = new HashMap<String, TabInfo>();
private TabInfo mLastTab = null;
private AdaptadorDePaginas mAdaptadorPaginas;
private ViewPager mViewPager;
private int posicion;
private FragmentManager supportFragmentManager;
private static Menu_Principal menu_principal;
public static TabsFragmentos newInstance() {
return new TabsFragmentos();
}
public TabsFragmentos(){
}
public TabsFragmentos(int position, Menu_Principal menu_principal, FragmentManager supportFragmentManager) {
this.posicion = position;
this.menu_principal = menu_principal;
this.supportFragmentManager = supportFragmentManager;
}
/**
*
* @author mwho
*
*/
private class TabInfo {
private String tag;
private Class<?> clss;
private Bundle args;
private android.support.v4.app.Fragment fragment;
TabInfo(String tag, Class<?> clazz, Bundle args) {
this.tag = tag;
this.clss = clazz;
this.args = args;
}
}
/**
*
* @author mwho
*
*/
class TabFactory implements TabContentFactory {
private final Context mContext;
/**
* @param context
*/
public TabFactory(Context context) {
mContext = context;
}
/** (non-Javadoc)
* @see android.widget.TabHost.TabContentFactory#createTabContent(String)
*/
public View createTabContent(String tag) {
View v = new View(mContext);
v.setMinimumWidth(0);
v.setMinimumHeight(0);
return v;
}
}
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
//int posicion = getArguments().getInt(ARGUMENTO_);
super.onCreate(savedInstanceState);
if (savedInstanceState != null) {
mTabHost.setCurrentTabByTag(savedInstanceState.getString("tab")); //set the tab as per the saved state
}
View rootView = null;
if (Menu_.MERCURY.getPosicion()== posicion){
//rootView = inflater.inflate(R.layout.fragmento_palabra_bk, container, false);
rootView = inflater.inflate(R.layout.fragmentos_base, container, false);
initialiseTabHost(rootView, savedInstanceState);
intialiseViewPager(rootView);
}
return rootView;
}
/** (non-Javadoc)
* @see android.support.v4.app.FragmentActivity#onSaveInstanceState(android.os.Bundle)
*/
public void onSaveInstanceState(Bundle outState) {
outState.putString("tab", mTabHost.getCurrentTabTag()); //save the tab selected
super.onSaveInstanceState(outState);
}
/**
* Initializando el TabHost
*/
private void initialiseTabHost(View rootView, Bundle args) {
mTabHost = (TabHost)rootView.findViewById(android.R.id.tabhost);
//mTabHost = (TabHost)findViewById(android.R.id.tabhost);
mTabHost.setup();
TabInfo tabInfo = null;
TabsFragmentos.addTab(this, this.mTabHost, this.mTabHost.newTabSpec("Tab2").setIndicator("Buscar"), ( tabInfo = new TabInfo("Tab1", TabFragmentOne.class, args)));
this.mapTabInfo.put(tabInfo.tag, tabInfo);
TabsFragmentos.addTab(this, this.mTabHost, this.mTabHost.newTabSpec("Tab1").setIndicator("Crear"), ( tabInfo = new TabInfo("Tab2", TabFragmentTwo.class, args)));
this.mapTabInfo.put(tabInfo.tag, tabInfo);
// Default to first tab
this.onTabChanged("Tab1");
mTabHost.setOnTabChangedListener(this);
}
private void intialiseViewPager(View rootView) {
List<android.support.v4.app.Fragment> fragments = new Vector<android.support.v4.app.Fragment>();
fragments.add(android.support.v4.app.Fragment.instantiate(menu_principal, TabFragmentOne.class.getName()));
fragments.add(android.support.v4.app.Fragment.instantiate(menu_principal, TabFragmentTwo.class.getName()));
this.mAdaptadorPaginas = new AdaptadorDePaginas(supportFragmentManager, fragments);
//
this.mViewPager = (ViewPager)rootView.findViewById(R.id.tabviewpager);
this.mViewPager.setAdapter(this.mAdaptadorPaginas);
this.mViewPager.setOnPageChangeListener(this);
}
/**
* @param activity
* @param tabHost
* @param tabSpec
*/
private static void addTab(TabsFragmentos activity, TabHost tabHost, TabHost.TabSpec tabSpec, TabInfo tabInfo) {
// Attach a Tab view factory to the spec
tabSpec.setContent(activity.new TabFactory(menu_principal));
String tag = tabSpec.getTag();
// Check to see if we already have a fragment for this tab, probably
// from a previously saved state. If so, deactivate it, because our
// initial state is that a tab isn''t shown.
if (tabInfo.fragment != null && !tabInfo.fragment.isDetached()) {
FragmentTransaction ft = menu_principal.getSupportFragmentManager().beginTransaction();
ft.detach(tabInfo.fragment);
ft.commit();
menu_principal.getSupportFragmentManager().executePendingTransactions();
}
tabHost.addTab(tabSpec);
}
public void onTabChanged(String tag) {
try{
//TabInfo newTab = this.mapTabInfo.get(tag);
int pos = this.mTabHost.getCurrentTab();
this.mViewPager.setCurrentItem(pos);
}catch(Exception e){}
}
@Override
public void onPageScrolled(int i, float v, int i2) {
}
@Override
public void onPageSelected(int position) {
// TODO Auto-generated method stub
this.mTabHost.setCurrentTab(position);
}
@Override
public void onPageScrollStateChanged(int i) {
}
}

¿Cuál es el problema?

el código funciona bien la primera vez ... solo presionó cualquier opción y muestra las pestañas con su diseño asociado a los fragmentos TabFragmentOne o TabFragmentTwo. la segunda vez, este código solo muestra las pestañas pero no muestra el diseño asociado a los fragmentos TabFragmentOne o TabFragmentTwo.

¿que debería hacer?

Thx 4 de avance.

Answer 1

Para mí, el problema estaba en mi TabsAdapter . El único constructor se veía así:

public TabsAdapter(FragmentActivity activity, TabHost tabHost, ViewPager pager) {
super(activity.getSupportFragmentManager());
mContext = activity;
mTabHost = tabHost;
mViewPager = pager;
mTabHost.setOnTabChangedListener(this);
mViewPager.setAdapter(this);
mViewPager.setOnPageChangeListener(this);
}

getSupportFragmentManager a getSupportFragmentManager que devuelve el FragmentManager asociado a nuestra FragmentActivity . Malo. Necesitamos la FM que gestiona nuestro Fragment actual. Crear un constructor alternativo (sobrecargado) que usara getChildFragmentManager hizo el truco.

public TabsAdapter(Fragment fragment, TabHost tabHost, ViewPager pager) {
super(fragment.getChildFragmentManager());
mContext = fragment.getActivity();
mTabHost = tabHost;
mViewPager = pager;
mTabHost.setOnTabChangedListener(this);
mViewPager.setAdapter(this);
mViewPager.setOnPageChangeListener(this);
}

Su problema proviene del mismo problema, solo en un formato diferente. Reemplace sus llamadas a getSupportFragmentManager con getChildFragmentManager en su Fragment .