Question

我有一个项目需要有两个viewpager，每个都在活动的不同片段中。

这样的架构

问题是当寻呼机视图膨胀时，另一个不是。

例如，可以通过单击访问片段1,2和3。当我点击第一个片段时，它会完美地展开视图寻呼机及其两个片段，但是如果我点击片段3，则视图寻呼机不会使片段膨胀，而且标签也会变慢。再次打开应用程序进程，首先单击片段3，它运行正常，但点击后面的第一个，再次发生此问题。

已经调试过程，没有什么不同。

我的活动

public class HomeActivity extends AppCompatActivity implements NavigationFragment.OnNavigationListener{
public NavigationFragment mNavigation;

private String mTagFragmentShowing = "";
private int currentNavigation = 0;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_home);
    ButterKnife.bind(this);
    mNavigation = (NavigationFragment) getFragmentManager().findFragmentById(R.id.manager_navigation);

    onNavigationSelected(currentNavigation);
}


@Override
public void onNavigationSelected(int position) {
    if (mTagFragmentShowing.equals(String.valueOf(position)))
        return;

    currentNavigation = position;

    mNavigation.setNavigationSelected(position);
    FragmentManager fragmentManager = getSupportFragmentManager();
    Fragment fragment = fragmentManager.findFragmentByTag(mTagFragmentShowing);

    // Hide last fragment
    if (fragment != null && fragment.isVisible()) {
        fragmentManager.beginTransaction().hide(fragment).commit();
    }

    // Show new fragment
    mTagFragmentShowing = String.valueOf(position);
    fragment = fragmentManager.findFragmentByTag(mTagFragmentShowing);

    if (fragment != null && fragment.isHidden()) {
        fragmentManager.beginTransaction().show(fragment).commit();
    } else if (fragment == null) {
        fragmentManager.beginTransaction().add(R.id.manager_content, getFragmentByPosition(position), mTagFragmentShowing)
                .setTransition(FragmentTransaction.TRANSIT_NONE).commit();
    }
}

private Fragment getFragmentByPosition(int position) {
    switch (position) {
        case 0:
            return new DiscoverFragment();
        case 1:
            return new UpcomingFragment();
        case 2:
            return new FeaturesFragment();
        case 3:
            return new VideosFragment();
        case 4:
            return new MySongsFragment();
    }
    return null;
}

我的导航片段。它控制其他片段

public class NavigationFragment extends Fragment implements View.OnClickListener {

public ViewHolder mHolder;
public View mButtonSelected;
public OnNavigationListener mCallback;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.component_navigation, container, false);
    ButterKnife.bind(this, view);

    initView(view);
    return view;
}

public void initView(View view) {
    mHolder = new ViewHolder();
    mHolder.discover = view.findViewById(R.id.component_navigation_discover);
    mHolder.upcoming = view.findViewById(R.id.component_navigation_upcoming);
    mHolder.features = view.findViewById(R.id.component_navigation_features);
    mHolder.videos = view.findViewById(R.id.component_navigation_videos);
    mHolder.mymusic = view.findViewById(R.id.component_navigation_mymusic);

    mHolder.discover.setTag(0);
    mHolder.upcoming.setTag(1);
    mHolder.features.setTag(2);
    mHolder.videos.setTag(3);
    mHolder.mymusic.setTag(4);

    mHolder.discover.setOnClickListener(this);
    mHolder.upcoming.setOnClickListener(this);
    mHolder.features.setOnClickListener(this);
    mHolder.videos.setOnClickListener(this);
    mHolder.mymusic.setOnClickListener(this);
    mButtonSelected = mHolder.features;
}

public void setNavigationSelected(int position) {
    setNavigationButtonSelected(false);
    switch (position) {
        case 0:
            mButtonSelected = mHolder.discover;
            break;
        case 1:
            mButtonSelected = mHolder.upcoming;
            break;
        case 2:
            mButtonSelected = mHolder.features;
            break;
        case 3:
            mButtonSelected = mHolder.videos;
            break;
        case 4:
            mButtonSelected = mHolder.mymusic;
            break;
    }
    setNavigationButtonSelected(true);
}

public void setNavigationButtonSelected(boolean enabled) {
    mButtonSelected.setBackgroundColor(enabled ? getResources().getColor(R.color.color_red) : Color.TRANSPARENT);
}

@Override
public void onClick(View view) {
    if (view != mButtonSelected) {
        mCallback.onNavigationSelected((Integer) view.getTag());
    }
}

@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);

    try {
        mCallback = (OnNavigationListener) activity;
    } catch (ClassCastException e) {
        throw new ClassCastException(activity.toString()
                + " must implement OnNavigationSelectedListener");
    }
}

@Override
public void onDetach() {
    super.onDetach();
    mCallback = null;
}

static class ViewHolder {
    View discover;
    View upcoming;
    View features;
    View videos;
    View mymusic;
}

public interface OnNavigationListener {
    public void onNavigationSelected(int position);
}

My Fragments with View Pager

public class MySongsFragment extends Fragment {
private OnFragmentInteractionListener mListener;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    getActivity().getSupportFragmentManager().beginTransaction().add(R.id.mysongs_fragment_container, MySongsViewPagerFragment.newInstance(0)).commit();

    return inflater.inflate(R.layout.fragment_my_songs, container, false);
}


@Override
public void onDetach() {
    super.onDetach();
    mListener = null;
}

/**
 * This interface must be implemented by activities that contain this
 * fragment to allow an interaction in this fragment to be communicated
 * to the activity and potentially other fragments contained in that
 * activity.
 * <p/>
 * See the Android Training lesson <a href=
 * "http://developer.android.com/training/basics/fragments/communicating.html"
 * >Communicating with Other Fragments</a> for more information.
 */
public interface OnFragmentInteractionListener {
    // TODO: Update argument type and name
    public void onFragmentInteraction(Uri uri);
}

我的观看寻呼机

public class MySongsViewPagerFragment extends Fragment {

private static final int NUM_PAGES = 4;
private String[] tab_names;
private List<String> mTabNames;
private PagerAdapter mPagerAdapter;

public @Bind(R.id.pager)
ViewPager mPager;

public static MySongsViewPagerFragment newInstance(int index) {
    MySongsViewPagerFragment fragment = new MySongsViewPagerFragment();
    Bundle args = new Bundle();
    args.putInt("index", index);
    fragment.setArguments(args);
    return fragment;
}

@Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = initView(inflater, container);
    return view;
}

@NonNull private View initView(LayoutInflater inflater, ViewGroup container) {
    View view = inflater.inflate(R.layout.fragment_view_pager_my_songs, container, false);
    ButterKnife.bind(this, view);

    tab_names = getResources().getStringArray(R.array.tabs_mysongs);
    mTabNames = Arrays.asList(tab_names);

    mPagerAdapter = new ScreenSlidePagerAdapter(getActivity().getSupportFragmentManager());
    mPager.setAdapter(mPagerAdapter);

    mPager.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            mPager.onTouchEvent(event);
            return false;
        }
    });

    TabLayout tabLayout = (TabLayout) view.findViewById(R.id.tabs);
    tabLayout.setupWithViewPager(mPager);
    return view;
}



private class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter {
    public ScreenSlidePagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override public Fragment getItem(int position) {
        switch (position) {
            case 0:
                return new PlaylistsFragment();
            case 1:
                return new SongsFragment();
            case 2:
                return new AlbumsFragment();
            case 3:
                return new ArtistsFragment();
            default:
                return new PlaylistsFragment();
        }
    }

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

    @Override public CharSequence getPageTitle(int position) {
        return mTabNames.get(position);
    }
}

Answer 1

问题是viewpager中的活动上下文

在我的视图中寻呼机。我改变了

mPagerAdapter = new ScreenSlidePagerAdapter(getActivity().getSupportFragmentManager());
mPager.setAdapter(mPagerAdapter);

到

mPagerAdapter = new ScreenSlidePagerAdapter(getChildFragmentManager());
mPager.setAdapter(mPagerAdapter);

两个viewpager使用相同的上下文。因此，当我第一次膨胀时，另一个没有膨胀，因为解释说已经存在一个膨胀的观察者。

感谢mcwise帮助向我展示方法getChildFragmentManager（）。

Viewpager不会对已经给另一个视图寻呼机充气的片段进行充气

1 个答案: