哪个片段打开了活动？

Question

我有一个 viewpager，它有 4 个片段，它们都有 recyclerview。点击recyclerview，所有四个片段都打开同一个活动，即DemoActivity。我想在 DemoActivity 中显示不同的选项菜单，根据点击了 Fragmnet 的回收视图。我怎么会知道点击了哪个片段的回收视图并在 DemoActivity 中显示适当的选项菜单？

  public class CategoryAdapter extends FragmentPagerAdapter {
    private Context context;
    public CategoryAdapter(Context context,FragmentManager fm) {
        super(fm);
        this.context=context;
    }

    @Override
    public Fragment getItem(int position) {
        if(position==0){
            return new MyMoviesFragment();
        }
        else if(position==1){
            return new PopularFragment();
        }
        else if (position==2){
            return new UpComingFragment();
        }
        else{
            return new NowPlayingFragment();
        }

    }



    @Override
    public int getCount() {
        return 4;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        if(position==0){
            return context.getString(R.string.category_MyMovies);
        }
        else if(position==1){
            return context.getString(R.string.category_Popular);
        }

        else if(position==2){
            return context.getString(R.string.category_Upcoming);
        }
        else if(position==3){
            return context.getString(R.string.category_NowPlaying);
        }

        return super.getPageTitle(position);
    }
}

问题已编辑

Answer 1

in fragment (u can put this code inside your recycler view action listener )
Intent intent = new Intent(getActivity(), DemoActivity.class);
intent.putExtra("KEY", "UR_FRAGMENT_NAME");
startActivity(intent);

in DemoActivity inside onCreate() method
Intent intent  = getIntent();
if(intent.hasExtra("KEY")) {
   if(intent.getStringExtra("KEY").equals("UR_FRAGMENT_NAME")) {
     // todo what u want.
   }
}

Answer 2

如果您有ViewPager - 您可以使用一个职位选项。将您的fragment 的位置传递给您的DemoActivity.java。

为此，您必须从FragmentPagerAdpater 的getItem(int position) 方法传递位置，并将位置从Fragment 传递给Activity。

就像 -

@Override
public Fragment getItem(int position) {
    Fragment mF;
    if (position == 0) {
       mF = new MyMoviesFragment();
    } else if (position==1){
       mF = new PopularFragment();
    } else if (position==2){
       mF = new UpComingFragment();
    } else {
       mF = new NowPlayingFragment();
    }
    Bundle b = new Bundle();
    b.putInt("KEY", position); // You are passing position to fragment
    mF.setArguments(b);
    return mF;
}

现在使用getArguments() 方法在您的fragment 中获得位置。例如，在您的MyMoviesFragment -

Bundle b = getArguements();
int position = b.getInt("KEY");

您已经在Fragment 中获得了职位，现在通过点击recyclerview 项目将其传递给Activity -

Intent i = new Intent(context, DemoActivity.class);
i.putExtra("NEW_KEY", position); // position is being passed to activity, retrieve in Activity using getExtras() and use it as needed.
startActivity(i);

你已经完成了！