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在viewpager片段項目中水平滾動時,它僅顯示三個選項卡的一個片段(fragment_main.xml)。當用戶水平滾動時如何鏈接第二個片段(fragment2.xml)。如何將不同的片段添加到相同的ViewPager?

這裏是我的代碼

MainActivity

public class MainActivity extends ActionBarActivity implements ActionBar.TabListener { 
/** 
* The {@link android.support.v4.view.PagerAdapter} that will provide 
* fragments for each of the sections. We use a 
* {@link 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_main); 

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

    // Create the adapter that will return a fragment for each of the three 
    // primary sections of the activity. 
    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 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.main, menu); 
    return true; 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    // Handle action bar item clicks here. The action bar will 
    // automatically handle clicks on the Home/Up button, so long 
    // as you specify a parent activity in AndroidManifest.xml. 
    int id = item.getItemId(); 
    if (id == R.id.action_settings) { 
     return true; 
    } 
    return super.onOptionsItemSelected(item); 
} 

@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. 
     // Return a PlaceholderFragment (defined as a static inner class below). 
     return PlaceholderFragment.newInstance(position + 1); 
    } 

    @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 getString(R.string.title_section1).toUpperCase(l); 
      case 1: 
       return getString(R.string.title_section2).toUpperCase(l); 
      case 2: 
       return getString(R.string.title_section3).toUpperCase(l); 
     } 
     return null; 
    } 
} 

/** 
* A placeholder fragment containing a simple view. 
*/ 
public static class PlaceholderFragment extends Fragment { 
    /** 
    * The fragment argument representing the section number for this 
    * fragment. 
    */ 
    private static final String ARG_SECTION_NUMBER = "section_number"; 

    /** 
    * Returns a new instance of this fragment for the given section 
    * number. 
    */ 
    public static PlaceholderFragment newInstance(int sectionNumber) { 
     PlaceholderFragment fragment = new PlaceholderFragment(); 
     Bundle args = new Bundle(); 
     args.putInt(ARG_SECTION_NUMBER, sectionNumber); 
     fragment.setArguments(args); 
     return fragment; 
    } 

    public PlaceholderFragment() { 
    } 

    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
      Bundle savedInstanceState) { 
     View rootView = inflater.inflate(R.layout.fragment_main, container, false); 
     return rootView; 
    } 
} 

}

activity_main.xml中

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

fragment_main.xml

<RelativeLayout 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" 
    android:paddingBottom="@dimen/activity_vertical_margin" 
    android:paddingLeft="@dimen/activity_horizontal_margin" 
    android:paddingRight="@dimen/activity_horizontal_margin" 
    android:paddingTop="@dimen/activity_vertical_margin" 
    tools:context="com.example.fragment.MainActivity$PlaceholderFragment" > 

    <TextView 
     android:id="@+id/section_label" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignParentTop="true" 
     android:layout_centerHorizontal="true" 
     android:layout_marginTop="230dp" 
     android:text="1st Fragment" /> 

</RelativeLayout> 

先謝謝了:-)

回答

1

如果您需要分配一個全新的片段和不一樣的片段,但使用不同的參數只是一個頁面,你將需要創建一個第二個片段就像PlaceHolderFragment,然後在適配器的getItem()上,您將需要爲不同的位置返回不同的片段。

@Override 
public Fragment getItem(int position) { 
    Fragment fragment = null; 
    switch(position) { 
     case 0: 
      fragment = new PlaceHolderFragment(); 
      break; 
     case 1: 
      fragment = new PlaceHolderFragment2(); 
      break; 
    } 
    return fragment; 
} 
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