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Android Android Fragments Managing Fragments Adding the ViewPager

chandrashekhar singh
chandrashekhar singh
507 Points

I am getting this problem

Process: com.csing1s.myapplication, PID: 12912 java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v4.view.ViewPager.setAdapter(android.support.v4.view.PagerAdapter)' on a null object reference at com.csing1s.myapplication.ViewPagerFragment.onCreateView(ViewPagerFragment.java:36) at android.support.v4.app.Fragment.performCreateView(Fragment.java:1974) at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067) at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1252) at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:738) at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1617) at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:517) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:155)

1 Answer

Ben Deitch
Ben Deitch
Treehouse Teacher

Hey Chandrashekhar! Let's see if we can't reason through what this error might mean. It looks like you're trying to call, 'setAdapter' on a null object reference. So I'd guess it's the 'viewPager' that's null. Then, since we set the 'viewPager' by using the 'findViewById' funcion, and since the 'findViewById' function returns null if it doesn't find that id. I'm going to guess that the id you're passing into 'findViewById' doesn't exist.