ViewPager + TabsAdapter + Fragment

Question

  

可能重复：
  Android PagerView between Activities

我希望有一个带有标签的viewpager，以及一个每个都有各自xml布局文件的片段类。我该如何做到这一点？这是我到目前为止，但它在调试中出现错误：

Fragment.instantiate(Context, String, Bundle) line: 574 

有人能帮助我吗？我知道这可能是一个noob问题，并且有一个简单的解决方案。 :)

这是我的ViewPager和TabsAdapter：

public class WMAlphaTestActivity extends Activity {
ViewPager mViewPager;
TabsAdapter mTabsAdapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    mViewPager = new ViewPager(this);
    mViewPager.setId(R.id.pager);
    setContentView(mViewPager);

    final ActionBar bar = getActionBar();
    bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
    bar.setDisplayOptions(0, ActionBar.DISPLAY_SHOW_TITLE);

    mTabsAdapter = new TabsAdapter(this, mViewPager);
    mTabsAdapter.addTab(bar.newTab().setText("1"),
            1.class, null);
    mTabsAdapter.addTab(bar.newTab().setText("2"),
            2.class, null);
    mTabsAdapter.addTab(bar.newTab().setText("3"),
            3.class, null);

    if (savedInstanceState != null) {
        bar.setSelectedNavigationItem(savedInstanceState.getInt("tab", 0));
    }
}

@Override
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    outState.putInt("tab", getActionBar().getSelectedNavigationIndex());
}

public static class TabsAdapter extends FragmentPagerAdapter
        implements ActionBar.TabListener, ViewPager.OnPageChangeListener {
    private final Context mContext;
    private final ActionBar mActionBar;
    private final ViewPager mViewPager;
    private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();

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

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

    public TabsAdapter(Activity activity, ViewPager pager) {
        super(activity.getFragmentManager());
        mContext = activity;
        mActionBar = activity.getActionBar();
        mViewPager = pager;
        mViewPager.setAdapter(this);
        mViewPager.setOnPageChangeListener(this);
    }

    public void addTab(ActionBar.Tab tab, Class<?> clss, Bundle args) {
        TabInfo info = new TabInfo(clss, args);
        tab.setTag(info);
        tab.setTabListener(this);
        mTabs.add(info);
        mActionBar.addTab(tab);
        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);
    }

    @Override
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
    }

    @Override
    public void onPageSelected(int position) {
        mActionBar.setSelectedNavigationItem(position);
    }

    @Override
    public void onPageScrollStateChanged(int state) {
    }

    @Override
    public void onTabSelected(Tab tab, FragmentTransaction ft) {
        Object tag = tab.getTag();
        for (int i=0; i<mTabs.size(); i++) {
            if (mTabs.get(i) == tag) {
                mViewPager.setCurrentItem(i);
            }
        }
    }

    @Override
    public void onTabUnselected(Tab tab, FragmentTransaction ft) {
    }

    @Override
    public void onTabReselected(Tab tab, FragmentTransaction ft) {
    }
}
}

现在这里是每个片段类的样子

public class WMAdded extends Fragment {

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    return (RelativeLayout) inflater.inflate(R.layout.wmadded, container, false);

} }