Android Fragment backStack問題

Question

我的Activity中有以下代碼：

     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();
            }

它按預期工作，我可以在點擊幾次之前回到以前的狀態。 但是，如果我只深入一個，我會得到以下異常：

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，如果我只調用一次替換，當我按下后退按鈕時，它會出錯。

另外，使用ListFragment，我是否必須將背景設置為白色？ 我沒碰到它，我可以看到舊的列表視圖顯示....

謝謝！

Answer 1

那么，你遇到的問題是沒有片段可以回去。 這就是你能做的。 1：檢查片段是否存在於backstack中（通過給它命名）然后禁用返回2：當你第一次啟動程序時，在backstack中添加一個片段，就像它點擊之前的初始狀態一樣。 即使在這種情況下，你仍然需要做一個chck，看看是否有任何東西留在靠背中回去。