Android的标签听众保持2个标签活着背景

Question

我在我的应用程序标签activty，

这里是一些简单的代码：

@SuppressLint("NewApi") 
public class Rhino68PanelActivity extends FragmentActivity implements ActionBar.TabListener { 

static String TAG = "Rhino68PanelActivty"; 

/** 
* The {@link android.support.v4.view.PagerAdapter} that will provide 
* fragments for each of the sections. We use a 
* {@link android.support.v4.app.FragmentPagerAdapter} derivative, which 
* will keep every loaded fragment in memory. If this becomes too memory 
* intensive, it may be best to switch to a 
* {@link android.support.v4.app.FragmentStatePagerAdapter}. 
*/ 
SectionsPagerAdapter mSectionsPagerAdapter; 

/** 
* The {@link ViewPager} that will host the section contents. 
*/ 
ViewPager mViewPager; 


@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_rhino68_panel); 

    // Set up the action bar. 
    final ActionBar actionBar = getActionBar(); 
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS); 

    // Create the adapter that will return a fragment for each of the three 
    // primary sections of the app. 
    mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager()); 

    // Set up the ViewPager with the sections adapter. 
    mViewPager = (ViewPager) findViewById(R.id.pager); 
    mViewPager.setAdapter(mSectionsPagerAdapter); 

    // When swiping between different sections, select the corresponding 
    // tab. We can also use ActionBar.Tab#select() to do this if we have 
    // a reference to the Tab. 
    mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() { 
     @Override 
     public void onPageSelected(int position) { 
      actionBar.setSelectedNavigationItem(position); 
     } 
    }); 

    // For each of the sections in the app, add a tab to the action bar. 
    for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) { 
     // Create a tab with text corresponding to the page title defined by 
     // the adapter. Also specify this Activity object, which implements 
     // the TabListener interface, as the callback (listener) for when 
     // this tab is selected. 
     actionBar.addTab(actionBar.newTab().setText(mSectionsPagerAdapter.getPageTitle(i)).setTabListener(this)); 
    } 
} 

@Override 
protected void onDestroy() { 
    super.onDestroy(); 
    Network.cancelRequests(Rhino68PanelActivity.this); 
} 

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.rhino68_panel, menu); 
    return true; 
} 

@Override 
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) { 
    // When the given tab is selected, switch to the corresponding page in 
    // the ViewPager. 
    mViewPager.setCurrentItem(tab.getPosition()); 
} 

@Override 
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) { 
} 

@Override 
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) { 
} 

/** 
* A {@link FragmentPagerAdapter} that returns a fragment corresponding to 
* one of the sections/tabs/pages. 
*/ 
public class SectionsPagerAdapter extends FragmentPagerAdapter { 

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

    @Override 
    public Fragment getItem(int position) { 
     // getItem is called to instantiate the fragment for the given page. 
     Fragment fragment = null; 

     switch (position) { 
     case 0: { 
      fragment = new OneSectionFragment(); 
     } 
      break; 
     case 1: { 
      fragment = new TwoSectionFragment(); 
     } 
      break; 
     case 2: { 
      fragment = new ThreeSectionFragment(); 
     } 
      break; 
     default: { 
      fragment = new OneSectionFragment(); 
     } 
     } 
     return fragment; 
    } 

    @Override 
    public int getCount() { 
     // Show 3 total pages. 
     return 3; 
    } 

    @Override 
    public CharSequence getPageTitle(int position) { 
     Locale l = Locale.getDefault(); 
     switch (position) { 
     case 0: 
      return "1"; 
     case 1: 
      "2"; 
     case 2: 
      "3"; 
     } 
     return null; 
    } 
} 

public static class oneSectionFragment extends Fragment { 


    private static Context mContext; 

    public StatusSectionFragment() { 
    } 

    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
     View rootView = inflater.inflate(R.layout.fragment_rhino68_panel_status, container, false); 
     mContext = getActivity(); 
     // update view 
     .... 
     return rootView; 
    } 
    //fucntions and methods 
} 

    public static class twoSectionFragment extends Fragment { 


    private static Context mContext; 

    public StatusSectionFragment() { 
    } 

    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
     View rootView = inflater.inflate(R.layout.fragment_rhino68_panel_status, container, false); 
     mContext = getActivity(); 
     // update view 
     .... 
     return rootView; 
    } 
    //fucntions and methods 
} 

现在我已经发现了一些奇怪的，这林不知道，如果它是如何工作，或者如果我做错了什么。

我在我的每个片段onCreateView()中设置了一个中断点，现在取决于我如何在标签之间导航断点的命中与否。

的情况下1： 如果我开始选项卡1，然后导航到选项卡2 - 不破发点被击中 如果我再回去标签1 - 再无破发点被击中

的情况下2： 如果我从标签1开始，然后导航到标签2 - 如果我然后转到标签3，则不会触发中断点 - 如果我然后再转到2 - 没有中断点 ，则标签3中的断点被击中， 去1 - 选项卡1中断点被击中

它似乎好像它加载标签号3当您点击标签号码2。 现在是标签管理器的属性了吗？或者我的标签管理器只认为有2个选项卡？

我在哪里运行的代码必须得到更新时，该选项卡实际上进入视图？

Answer 1

尝试使用：

mViewPager.setOffscreenPageLimit(x); 

该方法设置的应当保留在视图层次结构的当前页面的任一侧在空闲状态的页数。此设置默认为1. http://developer.android.com/reference/android/support/v4/view/ViewPager.html#setOffscreenPageLimit(int)