如何使用ViewPager在片段

Question

我下载一个大约ViewPager和CirclePageIndicator项目。它运作良好，在我的平板电脑和它的代码是：

Test1Activity.java：

TestFragmentAdapter mAdapter; 
ViewPager mPager; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 


    //The look of this sample is set via a style in the manifest 
    setContentView(R.layout.simple_circles); 

    mAdapter = new TestFragmentAdapter(getSupportFragmentManager()); 

    mPager = (ViewPager)findViewById(R.id.pager); 
    mPager.setAdapter(mAdapter); 

    CirclePageIndicator indicator = (CirclePageIndicator)findViewById(R.id.indicator); 
    indicator.setViewPager(mPager); 
} 

TestFragmentAdapter.java：

class TestFragmentAdapter extends FragmentPagerAdapter { 
protected static final String[] CONTENT = new String[] { "Page1", "Page2", "Page3", "Page4", }; 

private int mCount = CONTENT.length; 

public TestFragmentAdapter(FragmentManager fragmentManager) { 
    super(fragmentManager); 
} 

@Override 
public Fragment getItem(int position) { 
    return TestFragment.newInstance(CONTENT[position % CONTENT.length]); 
} 

@Override 
public int getCount() { 
    return mCount; 
} 

public void setCount(int count) { 
    if (count > 0 && count <= 10) { 
     mCount = count; 
     notifyDataSetChanged(); 
    } 
}} 

TestFragment：

public final class TestFragment extends Fragment { 
private static final String KEY_CONTENT = "TestFragment:Content"; 

public static TestFragment newInstance(String content) { 
    TestFragment fragment = new TestFragment(); 

    fragment.mContent = content; 

    return fragment; 
} 

private String mContent = "???"; 

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
    if ((savedInstanceState != null) && savedInstanceState.containsKey(KEY_CONTENT)) { 
     mContent = savedInstanceState.getString(KEY_CONTENT); 
    } 

    TextView text = new TextView(getActivity()); 
    text.setGravity(Gravity.CENTER); 
    text.setText(mContent); 
    text.setTextSize(20 * getResources().getDisplayMetrics().density); 
    text.setPadding(20, 20, 20, 20); 

    LinearLayout layout = new LinearLayout(getActivity()); 
    layout.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT)); 
    layout.setGravity(Gravity.CENTER); 
    layout.addView(text); 

    return layout; 
} 

@Override 
public void onSaveInstanceState(Bundle outState) { 
    super.onSaveInstanceState(outState); 
    outState.putString(KEY_CONTENT, mContent); 
}} 

现在我想在片段中使用此ViewPager而不是活动，但我感到困惑。 TestFragmentAdapter的构造函数接受类型android.support.v4.app.FragmentManager参数，但在一个片段我只能用getFragmentManager（）得到一个android.app.FragmentManager类型，因此

mAdapter = new TestFragmentAdapter(getSupportFragmentManager()); 

是总是错的。 我必须在几天内完成我的项目，那么你能告诉我如何修改我的代码以实现片段中的相同功能吗？

Thx !!

Answer 1

你有没有尝试extends android.support.v4.app.Fragment更换extends Fragment？

当你做到这一点，getFragmentManager（）是指android.support.v4.app.FragmentManager。

Answer 2

Android不支持片段的内部片段。无论是切换你ViewPager使用PagerAdapter不使用的片段，或者不把ViewPager的片段。

编辑：

现在，机器人通过使用Fragment.getChildFragmentManager()支持内部片段的片段。看看this answer。

Answer 3

将此代码放在您的MainActivity。以下代码将在您的布局中加载碎片。

步骤1

Fragment fragment = new PageSlider(); 
FragmentManager manager = getSupportFragmentManager(); 
manager.beginTransaction().replace(R.id.content, fragment).commit(); 

接下来，我们需要实现ViewPager

步骤2

public class PageSlider extends Fragment { 
public PageSlider() { 
// Required empty public constructor 
} 
@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
} 
@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
Bundle savedInstanceState) { 
// Inflate the layout for this fragment 
    return inflater.inflate(R.layout.page_slider, container, false); 
} 
@Override 
public void onViewCreated(View view, Bundle savedInstanceState) { 
// TODO Auto-generated method stub 
    super.onViewCreated(view, savedInstanceState); 
    PagerSlidingTabStrip tab = (PagerSlidingTabStrip) view 
.findViewById(com.akshay.protocol10.asplayer.R.id.tabs); 

ViewPager pager=(ViewPager)view .findViewById(com.akshay.protocol10.asplayer.R.id.view_pager); 
MyPagerAdapter adapter = new MyPagerAdapter(getChildFragmentManager()); 
pager.setAdapter(adapter); 
tab.setViewPager(pager); 
} 
// TODO: Rename method, update argument and hook method into UI event 
public void onButtonPressed(Uri uri) { 
} 
@Override 
public void onAttach(Activity activity) { 
super.onAttach(activity); 
} 
@Override 
public void onDetach() { 
super.onDetach(); 
} 
public interface OnFragmentInteractionListener { 
// TODO: Update argument type and name 
public void onFragmentInteraction(Uri uri); 
} 
} 

步骤3：创建适配器

public class MyPagerAdapter extends FragmentPagerAdapter { 
     private final String[] TITLES = { "Album", "Artist", "Songs", "Genre" }; 
     public MyPagerAdapter(FragmentManager childFragmentManager) { 
     // TODO Auto-generated constructor stub 
    super(childFragmentManager); 
    } 
    @Override 
    public CharSequence getPageTitle(int position) { 
    // TODO Auto-generated method stub 
    return TITLES[position]; 
    } 
    @Override 
    public Fragment getItem(int index) { 
    // TODO Auto-generated method stub 
     Fragment fragment = null; 
     if (index == 0) { 
     fragment = new Albums(); 
     } else if (index == 1) { 
     fragment = new ArtistFragment(); 
     } else if (index == 2) { 
     fragment = new TracksFragment(); 
     } else if (index == 3) { 
     fragment = new GenreFragment(); 
     } 
    return fragment; 
    } 

    @Override 
    public int getCount() { 
    // TODO Auto-generated method stub 
    return TITLES.length; 
    } 
    } 

Answer 4

检查片段延伸类应该从android.support.v4.app.Fragment导入不android.app.Fragment