Question

我正在尝试在ViewPager中扩充Fragments。当它第一次膨胀时，它会调用onCreateOptionMenu（）但不会使工具栏膨胀。

一旦ViewPager达到setoffscreenpagelimit片段数，它就会开始显示片段中的工具栏。

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setHasOptionsMenu(true);
}

@Override
public void onViewCreated(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
((AppCompatActivity) getActivity()).setSupportActionBar(toolbar);
((AppCompatActivity) getActivity()).getSupportActionBar().setHomeButtonEnabled(true);
((AppCompatActivity) getActivity()).getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}

@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    inflater.inflate(R.menu.menu, menu);
    super.onCreateOptionsMenu(menu, inflater);
}

Activity.java

@Override
protected void onCreate(Bundle savedInstanceState) { 
            mViewPager = (ViewPager) findViewById(R.id.viewPager);
            mViewPager.setOffscreenPageLimit(4);
            mPagerAdapter = new PagerAdapter(getFragmentManager());
            mViewPager.setAdapter(mPagerAdapter);
}

PagerAdapter.java：

public class PagerAdapter extends FragmentStatePagerAdapter {

Cursor mCursor;

public PagerAdapter(FragmentManager fm) {
    super(fm);
    //cursor initialization
}

@Override
public Fragment getItem(int position) {

    Fragment fragment = MyFragment.newInstance(position);
    return fragment;
}

@Override
public int getCount() {
    if (mCursor == null)
        return 0;
    else
        return mCursor.getCount();
}

public void swapCursor(Cursor cursor){
    mCursor = cursor;
    notifyDataSetChanged();
}

}

尝试从https://code.google.com/p/android/issues/detail?id=29472＆amp; OptionsMenu of Fragments in Viewpager showing each other's Buttons

仍然无法弄清楚为什么前4个片段没有膨胀。任何人都可以帮忙吗？

谢谢！

ViewPager中片段的Actionbar（工具栏）未显示

0 个答案: