Did a google search and wound up on stackoverflow, where Dianne Hackborn answered this question: http://stackoverflow.com/questions/8772921/how-to-pop-back-stack-for-activity-with-multiple-fragments
In short: The backstack doesn't work for 'inner' fragments, it only works for Activity (i.e. 'main') fragments, since the back stack seems to be tied to an Activity only, not to its Fragments. On Saturday, May 25, 2013 9:08:13 AM UTC-4, Miha wrote: > > Hi! > > Starting a new topic from > https://groups.google.com/forum/?fromgroups#!topic/android-developers/WgokX2uhv88; > > I have a situation where I'm using ViewPager to flip between fragments, and > two of the fragments have nested fragments. > > Fragment nesting is done via getChildFragmentManager and orientation > changes work as expected (fragments implement onSaveInstanceState), but > when trying to pop the backstack after user interactions, I just get a > NullPointerException or an "IllegalStateException: Activity has been > destroyed" depending on whether I use popBackStack or popBackStackImmediate. > > If I dump the child fragment state, it shows the activity as detached; If > I dump the "parent" fragment manager state, it shows all of the fragments > and also the activity reference (see below). > > I'm using support library, and with that, I'm using classes from > android.support.v4.app package. > > Child fragment state: > FragmentManager misc state: > mActivity=null > mContainer=android.support.v4.app.Fragment$1@41603ca0 > mParent=MainFilesFragment{4169ccf0} > mCurState=0 mStateSaved=false mDestroyed=false > > Parent fragment state: > Active Fragments in 414896e0: > #0: null > #1: ConnectFragment{41505ae0 #1 id=0x7f060001} > mFragmentId=#7f060001 mContainerId=#7f060001 mTag=null > mState=5 mIndex=1 mWho=android:fragment:1 mBackStackNesting=0 > mAdded=true mRemoving=false mResumed=true mFromLayout=false > mInLayout=false > mHidden=false mDetached=false mMenuVisible=false mHasMenu=false > mRetainInstance=false mRetaining=false mUserVisibleHint=false > mFragmentManager=FragmentManager{414896e0 in MainActivity{41489470}} > mActivity=com.islonline.isllightdesign.MainActivity@41489470 > mContainer=android.support.v4.view.ViewPager{4145c668 VFED.... > ........ 0,0-800,1033 #7f060001 app:id/pager} > mView=android.support.v4.app.NoSaveStateFrameLayout{414b1258 V.E..... > ........ 800,0-1600,1033} > mInnerView=android.support.v4.app.NoSaveStateFrameLayout{414b1258 > V.E..... ........ 800,0-1600,1033} > #2: MainFilesFragment{4155a430 #2 id=0x7f060001} > mFragmentId=#7f060001 mContainerId=#7f060001 mTag=null > mState=5 mIndex=2 mWho=android:fragment:2 mBackStackNesting=0 > mAdded=true mRemoving=false mResumed=true mFromLayout=false > mInLayout=false > mHidden=false *mDetached=false* mMenuVisible=true mHasMenu=false > mRetainInstance=false mRetaining=false mUserVisibleHint=true > mFragmentManager=FragmentManager{414896e0 in MainActivity{41489470}} > *mActivity=com.islonline.isllightdesign.MainActivity@41489470* > mContainer=android.support.v4.view.ViewPager{4145c668 VFED.... > ........ 0,0-800,1033 #7f060001 app:id/pager} > mView=android.support.v4.app.NoSaveStateFrameLayout{4155bcf8 V.E..... > ........ 1600,0-2400,1033} > mInnerView=android.support.v4.app.NoSaveStateFrameLayout{4155bcf8 > V.E..... ........ 1600,0-2400,1033} > Child FragmentManager{4155b598 in MainFilesFragment{4155a430}}: > Active Fragments in 4155b598: > #0: ComputerListFragment{4155b7b8 #0 id=0x7f060010 COMPUTER_LIST} > mFragmentId=#7f060010 mContainerId=#7f060010 mTag=COMPUTER_LIST > mState=1 mIndex=0 mWho=android:fragment:2:0 mBackStackNesting=1 > mAdded=false mRemoving=true mResumed=false mFromLayout=false > mInLayout=false > mHidden=false mDetached=false mMenuVisible=true mHasMenu=false > mRetainInstance=false mRetaining=false mUserVisibleHint=true > mFragmentManager=FragmentManager{4155b598 in > MainFilesFragment{4155a430}} > *mActivity=com.islonline.isllightdesign.MainActivity@41489470* > mParentFragment=MainFilesFragment{4155a430 #2 id=0x7f060001} > mSavedViewState=android.util.SparseArray@41690a60 > #1: FileShareBrowserFragment{41690840 #1 id=0x7f060010} > mFragmentId=#7f060010 mContainerId=#7f060010 mTag=null > mState=5 mIndex=1 mWho=android:fragment:2:1 mBackStackNesting=1 > mAdded=true mRemoving=false mResumed=true mFromLayout=false > mInLayout=false > mHidden=false mDetached=false mMenuVisible=true mHasMenu=false > mRetainInstance=false mRetaining=false mUserVisibleHint=true > mFragmentManager=FragmentManager{4155b598 in > MainFilesFragment{4155a430}} > *mActivity=com.islonline.isllightdesign.MainActivity@41489470* > mParentFragment=MainFilesFragment{4155a430 #2 id=0x7f060001} > mContainer=android.widget.FrameLayout{4155b210 V.E..... ........ > 0,0-800,1033 #7f060010 app:id/file_browser_container} > mView=android.support.v4.app.NoSaveStateFrameLayout{41698148 > V.E..... ........ 0,0-800,1033} > > mInnerView=android.support.v4.app.NoSaveStateFrameLayout{41698148 V.E..... > ........ 0,0-800,1033} > #2: null > Added Fragments: > #0: FileShareBrowserFragment{41690840 #1 id=0x7f060010} > Back Stack: > #0: BackStackEntry{41690780 #0} > mName=null mIndex=0 mCommitted=true > Operations: > Op #0: REPLACE FileShareBrowserFragment{41690840 #1 > id=0x7f060010} > Removed: ComputerListFragment{4155b7b8 #0 id=0x7f060010 > COMPUTER_LIST} > Back Stack Indices: > #0: BackStackEntry{41690780 #0} > > Thanks, > Miha. > -- -- You received this message because you are subscribed to the Google Groups "Android Developers" group. 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