android.support.v4.app.FragmentManager#popBackStackImmediate() results in a NullPointerException

问题

Sometimes executing android.support.v4.app.FragmentManager#popBackStackImmediate() results in the next exception:

> Fatal Exception: java.lang.NullPointerException: Attempt to invoke
> virtual method 'android.os.Handler
> android.support.v4.app.FragmentHostCallback.getHandler()' on a null
> object reference
>        at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1588)
>        at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:570)
>        at android.support.v4.app.FragmentManagerImpl.popBackStackImmediate(FragmentManager.java:585)

Here is my code:

        FragmentManager manager = getSupportFragmentManager();
        FragmentTransaction fragmentTransaction = manager.beginTransaction();
        manager.popBackStackImmediate();
        fragmentTransaction.commitAllowingStateLoss();

Does anyone knows what could be the reason for that?

回答1:

I moved back from compile 'com.android.support:support-v4:23.1.1' to compile 'com.android.support:support-v4:23.1.0' and now it doesn't happen any more. So to conclude, it seems like there is a bug with support-v4:23.1.1.

回答2:

this might work set noHistory flag false for the hosting activity

来源：https://stackoverflow.com/questions/34332900/android-support-v4-app-fragmentmanagerpopbackstackimmediate-results-in-a-null