Create a Nested Fragment

问题

I have MainLayout which contains multiple instances of DrawerLayout, each Drawerlayout has 3 items and every item has a fragment. When I click on an item its fragment displays on MainLayout by FragmentTransaction.

public boolean onNavigationItemSelected(MenuItem item) {
    // Handle navigation view item clicks here.
    int id = item.getItemId();

    if (id == R.id.home) {
        FragmentTransaction transaction = manager.beginTransaction();
        Hello f1 = new Hello();
        transaction.replace(R.id.main_layout,f1,"home");
        transaction.commit();

    }

Up to this point, the project runs without problems. But, I need to put Fragment inside an item's Fragment (nested Fragment). The Fragment of item already has a fragment inside of it, so how can I do this?

回答1:

You can nest a fragment inside another fragment using the host fragment's child fragment manager. An example setup can look like this:

HostFragment.java, a host fragment that hosts an arbitrary fragment:

public class HostFragment extends Fragment {
private Fragment hostedFragment;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    super.onCreateView(inflater, container, savedInstanceState);
    View view = inflater.inflate(R.layout.host_fragment, container, false);
    if (hostedFragment != null) {
        replaceFragment(hostedFragment);
    }
    return view;
}

public void replaceFragment(Fragment fragment) {
    getChildFragmentManager().beginTransaction().replace(R.id.hosted_fragment, fragment).commit();
}

public static HostFragment newInstance(Fragment fragment) {
    HostFragment hostFragment = new HostFragment();
    hostFragment.hostedFragment = fragment;
    return hostFragment;
}

}

host_fragment.xml, the layout inflated by the HostFragment class:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:id="@+id/hosted_fragment" >

</FrameLayout>

If you also need separate back navigation for each HostFragment, refer to this tutorial I've written about a similar situation with a ViewPager. Hopefully you can adapt the tutorial to your situation. Also refer to this and this section of codepath's guide about fragments.

来源：https://stackoverflow.com/questions/34619572/create-a-nested-fragment

标签

android

android-fragments

drawerlayout