导航抽屉与tabhost和viewpager

Question

IVe实现了一个带有少量片段的导航抽屉侧面菜单。对于每个片段，我实现了不同的实现。但是对于一个片段我已经用viewpager实现了Tabhost。但我面临的问题是Tabhost标签内容在第一次点击时可见。但是，如果您返回活动并返回活动，则标签内容不可见。而不是出现Tabhost线性布局背景。

MainActivity       import java.util.ArrayList;       import android.app.Activity;       import android.support.v4.app.Fragment;       import android.support.v4.app.FragmentActivity;       import android.support.v4.app.FragmentManager;       import android.content.res.Configuration;       import android.content.res.TypedArray;       import android.os.Bundle;       import android.support.v4.app.ActionBarDrawerToggle;       import android.support.v4.widget.DrawerLayout;       import android.util.Log;       import android.view.Menu;       import android.view.MenuItem;       import android.view.View;       import android.widget.AdapterView;       import android.widget.ListView;

  public class MainActivity extends FragmentActivity {
  private DrawerLayout mDrawerLayout;
  private ListView mDrawerList;
  private ActionBarDrawerToggle mDrawerToggle;

 // nav drawer title
  private CharSequence mDrawerTitle;

// used to store app title
 private CharSequence mTitle;

 // slide menu items

 private String[] navMenuTitles;
 private TypedArray navMenuIcons;

 private ArrayList<NavDrawerItem> navDrawerItems;
 private NavDrawerListAdapter adapter;

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

    mTitle = mDrawerTitle = getTitle();

    // load slide menu items
    navMenuTitles = getResources().getStringArray(R.array.nav_drawer_items);

    // nav drawer icons from resources
    navMenuIcons = getResources()
            .obtainTypedArray(R.array.nav_drawer_icons);

    mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
    mDrawerList = (ListView) findViewById(R.id.list_slidermenu);

    navDrawerItems = new ArrayList<NavDrawerItem>();

    // adding nav drawer items to array
    // Home
    navDrawerItems.add(new NavDrawerItem(navMenuTitles[0], navMenuIcons
            .getResourceId(0, -1)));
    // Find People
    navDrawerItems.add(new NavDrawerItem(navMenuTitles[1], navMenuIcons
            .getResourceId(1, -1)));
    // Photos
    navDrawerItems.add(new NavDrawerItem(navMenuTitles[2], navMenuIcons
            .getResourceId(2, -1)));
    // Communities, Will add a counter here
    navDrawerItems.add(new NavDrawerItem(navMenuTitles[3], navMenuIcons
            .getResourceId(3, -1)));
    // Pages
    navDrawerItems.add(new NavDrawerItem(navMenuTitles[4], navMenuIcons
            .getResourceId(4, -1)));
    // What's hot, We will add a counter here
    navDrawerItems.add(new NavDrawerItem(navMenuTitles[5], navMenuIcons
            .getResourceId(5, -1)));

    // Recycle the typed array
    navMenuIcons.recycle();

    mDrawerList.setOnItemClickListener(new SlideMenuClickListener());

    // setting the nav drawer list adapter
    adapter = new NavDrawerListAdapter(getApplicationContext(),
            navDrawerItems);
    mDrawerList.setAdapter(adapter);

    // enabling action bar app icon and behaving it as toggle button
    getActionBar().setDisplayHomeAsUpEnabled(false);
    getActionBar().setHomeButtonEnabled(true);

    mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
            R.drawable.ic_drawer, // nav menu toggle icon
            R.string.app_name, // nav drawer open - description for
                                // accessibility
            R.string.app_name // nav drawer close - description for
                                // accessibility
    ) {
        public void onDrawerClosed(View view) {
            getActionBar().setTitle(mTitle);
            // calling onPrepareOptionsMenu() to show action bar icons
            getActionBar().setIcon(R.drawable.ic_drawer);
            invalidateOptionsMenu();
        }

        public void onDrawerOpened(View drawerView) {
            getActionBar().setTitle(mDrawerTitle);
            // calling onPrepareOptionsMenu() to hide action bar icons
            getActionBar().setIcon(R.drawable.ic_closeone);
            invalidateOptionsMenu();
        }
    };
    mDrawerLayout.setDrawerListener(mDrawerToggle);

    if (savedInstanceState == null) {
        // on first time display view for first nav item
        displayView(0);
    }
}

/**
 * Slide menu item click listener
 * */
private class SlideMenuClickListener implements
        ListView.OnItemClickListener {
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position,
            long id) {
        // display view for selected nav drawer item
        displayView(position);
    }
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // toggle nav drawer on selecting action bar app icon/title
    if (mDrawerToggle.onOptionsItemSelected(item)) {
        return true;
    }
    // Handle action bar actions click
    switch (item.getItemId()) {
    case R.id.action_settings:
        return true;
    case R.id.logo:
        return true;
    default:
        return super.onOptionsItemSelected(item);
    }
}

/* *
 * Called when invalidateOptionsMenu() is triggered
 */
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
    // if nav drawer is opened, hide the action items
    boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
    menu.findItem(R.id.action_settings).setVisible(!drawerOpen);
    return super.onPrepareOptionsMenu(menu);
}

/**
 * Diplaying fragment view for selected nav drawer list item
 * */
private void displayView(int position) {
    // update the main content by replacing fragments
    Fragment fragment = null;
    switch (position) {
    case 0:
        fragment = new Home();
        break;
    case 1:
        fragment = new News();
        break;
    case 2:
        fragment = new Review();
        break;
    case 3:
        fragment = new Theaters();
        break;
    case 4:
        fragment = new Videos();
        break;
    case 5:
        fragment = new Photos();
        break;

    default:
        break;
    }

    if (fragment != null) {
        FragmentManager fragmentManager = getSupportFragmentManager();
        fragmentManager.beginTransaction()
                .replace(R.id.frame_container, fragment).commit();

        // update selected item and title, then close the drawer
        mDrawerList.setItemChecked(position, true);
        mDrawerList.setSelection(position);
        setTitle(navMenuTitles[position]);
        mDrawerLayout.closeDrawer(mDrawerList);
    } else {
        // error in creating fragment
        Log.e("MainActivity", "Error in creating fragment");
    }
}

@Override
public void setTitle(CharSequence title) {
    mTitle = title;
    getActionBar().setTitle(mTitle);
}

/**
 * When using the ActionBarDrawerToggle, you must call it during
 * onPostCreate() and onConfigurationChanged()...
 */

@Override
protected void onPostCreate(Bundle savedInstanceState) {
    super.onPostCreate(savedInstanceState);
    // Sync the toggle state after onRestoreInstanceState has occurred.
    mDrawerToggle.syncState();
}

@Override
public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);
    // Pass any configuration change to the drawer toggls
    mDrawerToggle.onConfigurationChanged(newConfig);
}

}

ReviewFragment

 import android.app.Activity;
 import android.os.Bundle;
 import android.support.annotation.Nullable;
 import android.support.v4.app.Fragment;
 import android.support.v4.app.FragmentManager;
 import android.support.v4.view.ViewPager;
 import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.TabHost;

 public class Review extends Fragment  {

 private TabHost mTabHost;
 private ViewPager mViewPager;
 private TabsPagerAdapter mTabsAdapter;


 public Review(){}

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

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

     return rootView;
 }  

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onActivityCreated(savedInstanceState);


    mTabHost = (TabHost) getActivity().findViewById(android.R.id.tabhost);
    mTabHost.setup();
    Log.e("mTabHost", mTabHost + "");

    mViewPager = (ViewPager) getActivity().findViewById(R.id.pager);
    Log.e("mViewPager", mViewPager + "");
    mTabsAdapter = new TabsPagerAdapter(getActivity(), mTabHost, mViewPager);

    // Here we load the content for each tab. 
    mTabsAdapter.addTab(mTabHost.newTabSpec("Audience").setIndicator("Audience"), AudienceFragment.class, null);
    mTabsAdapter.addTab(mTabHost.newTabSpec("Critics").setIndicator("Critics"), CriticsFragment.class, null);
    Log.e("mTabsAdapter", mTabsAdapter + "");
   /* 
    if (savedInstanceState != null) {
        mTabHost.setCurrentTabByTag(savedInstanceState.getString("tab"));
    }*/
}   
}

TabsPagerAdapter

  import android.content.Context;
  import android.os.Bundle;
  import android.support.v4.app.Fragment;
  import android.support.v4.app.FragmentActivity;
  import android.support.v4.app.FragmentPagerAdapter;
  import android.support.v4.view.ViewPager;
  import android.util.Log;
  import android.view.View;
  import android.view.ViewGroup;
  import android.widget.TabHost;
  import android.widget.TabWidget;
  import java.util.ArrayList;

  public class TabsPagerAdapter extends FragmentPagerAdapter
    implements TabHost.OnTabChangeListener, ViewPager.OnPageChangeListener {
private final Context mContext;
private final TabHost mTabHost;
private final ViewPager mViewPager;
private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();

static final class TabInfo
{
    private final String tag;
    private final Class<?> clss;
    private final Bundle args;

    TabInfo(String _tag, Class<?> _class, Bundle _args)
    {
        tag = _tag;
        clss = _class;
        args = _args;
    }
}

static class DummyTabFactory implements TabHost.TabContentFactory
{
    private final Context mContext;

    public DummyTabFactory(Context context)
    {
        mContext = context;
    }

    public View createTabContent(String tag)
    {
        View v = new View(mContext);
        v.setMinimumWidth(0);
        v.setMinimumHeight(0);
        return v;
    }
}

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


public void addTab(TabHost.TabSpec tabSpec, Class<?> clss, Bundle args)
{
    tabSpec.setContent(new DummyTabFactory(mContext));
    String tag = tabSpec.getTag();

    TabInfo info = new TabInfo(tag, clss, args);
    mTabs.add(info);
    mTabHost.addTab(tabSpec);
    notifyDataSetChanged();
}

@Override
public int getCount()
{
    return mTabs.size();
}

@Override
public Fragment getItem(int position)
{
    TabInfo info = mTabs.get(position);

    return Fragment.instantiate(mContext, info.clss.getName(), info.args);

}

public void onTabChanged(String tabId)
{
    int position = mTabHost.getCurrentTab();
    mViewPager.setCurrentItem(position);

}

public String getTag()
{           
    return mTabHost.getCurrentTabTag();
}

public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels)
{
     int pos = this.mViewPager.getCurrentItem();
     this.mTabHost.setCurrentTab(pos);
}

public void onPageSelected(int position)
{
    // Unfortunately when TabHost changes the current tab, it kindly
    // also takes care of putting focus on it when not in touch mode.
    // The jerk.
    // This hack tries to prevent this from pulling focus out of our
    // ViewPager.
    TabWidget widget = mTabHost.getTabWidget();
    int oldFocusability = widget.getDescendantFocusability();
    widget.setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS);
    mTabHost.setCurrentTab(position);
    widget.setDescendantFocusability(oldFocusability);
}

public void onPageScrollStateChanged(int state)
{
}
}