Android的碎片堆棧中的問題

Question

我在我的活動下面的代碼：

 public void categoryClicked(int categoryId, String categoryName) {     


ItemList newFragment = ItemList.newInstance(categoryId); 
        FragmentTransaction ft = getFragmentManager().beginTransaction(); 
        ft.replace(R.id.itemContainer, newFragment); 
        ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN); 
        ft.addToBackStack(null);   
        ft.commit(); 
      } 

它正常工作，我可以點擊幾次到以前的狀態後回去。但是，如果我只去一個深，我得到以下異常：

03-10 22:17:19.895: ERROR/AndroidRuntime(23075): java.lang.IllegalStateException: Content view not yet created 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at android.app.ListFragment.ensureList(ListFragment.java:377) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at android.app.ListFragment.getListView(ListFragment.java:277) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at com.xxxxx.fragment.ItemList.onActivityCreated(ItemList.java:67) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:749) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:921) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at android.app.BackStackRecord.popFromBackStack(BackStackRecord.java:639) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at android.app.FragmentManagerImpl.popBackStackState(FragmentManager.java:1254) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at android.app.FragmentManagerImpl.popBackStackImmediate(FragmentManager.java:402) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at android.app.Activity.onBackPressed(Activity.java:2057) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at android.app.Activity.onKeyDown(Activity.java:1953) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at android.view.KeyEvent.dispatch(KeyEvent.java:2335) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at android.app.Activity.dispatchKeyEvent(Activity.java:2236) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchKeyEvent(PhoneWindow.java:1648) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at android.view.ViewRoot.deliverKeyEventPostIme(ViewRoot.java:2682) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at android.view.ViewRoot.handleFinishedEvent(ViewRoot.java:2655) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at android.view.ViewRoot.handleMessage(ViewRoot.java:1952) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at android.os.Handler.dispatchMessage(Handler.java:99) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at android.os.Looper.loop(Looper.java:126) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at android.app.ActivityThread.main(ActivityThread.java:3997) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at java.lang.reflect.Method.invokeNative(Native Method) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at java.lang.reflect.Method.invoke(Method.java:491) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599) 
03-10 22:17:19.895: ERROR/AndroidRuntime(23075):  at dalvik.system.NativeStart.main(Native Method) 

所以基本上，如果我只叫更換一次，錯誤出在我的時候我打的後退按鈕。

此外，與ListFragment，我必須將背景設置爲白色？我沒有碰它，我可以看到舊的列表顯示通過...

謝謝！

Answer 1

那麼，你遇到的問題是沒有片段可以回去。這是你可以做的。 1：檢查片段是否存在於後臺（通過給它一個名字），然後禁用返回 2：當你第一次啓動你的程序時，添加一個片段到後臺堆棧，就像它被點擊之前的初始狀態。即使在這種情況下，你仍然需要做一些事情來查看是否有任何東西留在了堆棧裏。