Causing A Java.illegalstateexception Error, No Activity, Only When Navigating To Fragment For The Second Time

June 12, 2024 Post a Comment

I am getting a very puzzling bug that I have no idea how to even begin working through. I have a simple app with one activity, the views are implemented with Fragments. One of th

Solution 1:

I followed the link in jeremyvillalobos answer (which was very helpful) that led me to this workaround.

publicclassCustomFragmentextendsFragment {
    privatestaticfinal Field sChildFragmentManagerField;

    static {
        Fieldf=null;
        try {
            f = Fragment.class.getDeclaredField("mChildFragmentManager");
            f.setAccessible(true);
        } catch (NoSuchFieldException e) {
            Log.e(LOGTAG, "Error getting mChildFragmentManager field", e);
        }
        sChildFragmentManagerField = f;
    }

    @OverridepublicvoidonDetach() {
        super.onDetach();

        if (sChildFragmentManagerField != null) {
            try {
                sChildFragmentManagerField.set(this, null);
            } catch (Exception e) {
                Log.e(LOGTAG, "Error setting mChildFragmentManager field", e);
            }
        }
    }

    ...
}

It works for me well, without the need to reinstantiate the fragment.

Solution 2:

This appears to be a bug reported at

https://code.google.com/p/android/issues/detail?id=42601

The variable

FragmentManagerImpl mChildFragmentManager;

In Fragment.java is not set to null on detach. So the next time the fragment is loaded, the variable still points to the last parent.

As discussed on that thread, a workaround is to reinstantiate the Fragment.

In my case, I was switching between fragments in an ActionBar tab. The troubled Fragment has nested Fragments and was crashing the app when coming back to the file loader Fragment. So this is the work-around code:

classMainTabsListenerimplementsActionBar.TabListener {
    public Fragment fragment;
    publicint TabPosition;

    publicMainTabsListener(Fragment fragment, int tab_position) {
        this.fragment = fragment;
        TabPosition = tab_position;
    }

    @OverridepublicvoidonTabReselected(Tab tab, FragmentTransaction ft) {
    }

    @OverridepublicvoidonTabSelected(Tab tab, FragmentTransaction ft) {
        CurrentFragment = fragment;
        CurrentTabSelectedPos = TabPosition;

        /**
         * This is a work-around for Issue 42601
         * https://code.google.com/p/android/issues/detail?id=42601
         * 
         * The method getChildFragmentManager() does not clear up
         * when the Fragment is detached.
         */if( fragment instanceof FileLoaderFragment ){
            fragment = reinstatiateFileLoaderFragment();
        }

        ft.replace(R.id.fragment_container, fragment);

    }

    @OverridepublicvoidonTabUnselected(Tab tab, FragmentTransaction ft) {
        ft.remove(fragment);
    }

}

Solution 3:

sadly, it's a bug of support v4, still there :(

When you choose other Fragment via Navigation Drawer or other thing like it, the fragment which has sub-fragments is detached. So those sub-fragments' fragmentManager(getChildFragmentManager()) is no longer exist. while those fragments return, error occurred. Bomb!

Obviously, support v4 should clean mChildFragmentManager in onDetach(), but it didn't, so we must depend on ourselves. such as following codes in the fragment which has sub-fragments:

@Override
    publicvoidonDetach() {
        try {
            Field childFragmentManager = Fragment.class.getDeclaredField("mChildFragmentManager");
            childFragmentManager.setAccessible(true);
            childFragmentManager.set(this, null);
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
        super.onDetach();
    }

Everything will be OK, have a good day :)

Baca Juga

Solution 4:

may your error is android.view.InflateException?

if so,you should inflate Fragment dynamically ,don't use XML layout.

and, you should not target fragment which is defined XML Layout to Fragment Transaction.

Solution 5:

I have the same problem.

In an activity, i have 3 bouttons to switch fragment with transaction.replace(...)

FragmentTransaction transaction = getSupportFragmentManager().beginTransaction(); transaction.replace(R.id.layout_tablet_paneau, mLigneMessageFragment);

One of this fragment contain a ViewPage with a custom FragmentPagerAdapter. Therefore, i must do getChildFragmentManager(), to alowed nested Fragments.

the constructor is here:

public LignePagerAdapter(Fragment ligneMessageTabletFragment) {
        super(ligneMessageTabletFragment.getChildFragmentManager());
    }

So i have the same error: The first show of this fragment wrorks, but when i show other fragment and go back on this one, i get this exception:

02-26 11:57:50.798: D/ACRA(776): Wait for Toast + worker ended. Kill Application ? true
02-26 11:57:50.798: E/AndroidRuntime(776): FATAL EXCEPTION: main
02-26 11:57:50.798: E/AndroidRuntime(776): java.lang.IllegalStateException: No activity
02-26 11:57:50.798: E/AndroidRuntime(776):  at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1075)
02-26 11:57:50.798: E/AndroidRuntime(776):  at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1070)
02-26 11:57:50.798: E/AndroidRuntime(776):  at android.support.v4.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManager.java:1861)
02-26 11:57:50.798: E/AndroidRuntime(776):  at android.support.v4.app.Fragment.performActivityCreated(Fragment.java:1474)
02-26 11:57:50.798: E/AndroidRuntime(776):  at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:931)
02-26 11:57:50.798: E/AndroidRuntime(776):  at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1088)
02-26 11:57:50.798: E/AndroidRuntime(776):  at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
02-26 11:57:50.798: E/AndroidRuntime(776):  at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1444)
02-26 11:57:50.798: E/AndroidRuntime(776):  at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:429)
02-26 11:57:50.798: E/AndroidRuntime(776):  at android.os.Handler.handleCallback(Handler.java:587)
02-26 11:57:50.798: E/AndroidRuntime(776):  at android.os.Handler.dispatchMessage(Handler.java:92)
02-26 11:57:50.798: E/AndroidRuntime(776):  at android.os.Looper.loop(Looper.java:132)
02-26 11:57:50.798: E/AndroidRuntime(776):  at android.app.ActivityThread.main(ActivityThread.java:4126)
02-26 11:57:50.798: E/AndroidRuntime(776):  at java.lang.reflect.Method.invokeNative(Native Method)
02-26 11:57:50.798: E/AndroidRuntime(776):  at java.lang.reflect.Method.invoke(Method.java:491)
02-26 11:57:50.798: E/AndroidRuntime(776):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:844)
02-26 11:57:50.798: E/AndroidRuntime(776):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:602)
02-26 11:57:50.798: E/AndroidRuntime(776):  at dalvik.system.NativeStart.main(Native Method)
02-26 11:57:52.818: I/dalvikvm(776): threadid=4: reacting to signal 3
02-26 11:57:52.818: I/dalvikvm(776): Wrote stack traces to '/data/anr/traces.txt'

So instead of put the same instance of fragment, i can re-create this so it fix the problem, but i seem not efficient.

transaction.replace(R.id.layout_tablet_paneau, LigneMessageTabletFragment.newInstance());

friednshipgoneforlife