Android FragmentManager BackStackRecord.run throwing NullPointerException

執行代碼：錯誤：
java.lang.NullPointerException
11-15 09:04:21.023: E/AndroidRuntime(4057):     at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:591)
11-15 09:04:21.023: E/AndroidRuntime(4057):     at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1416

if (mCurTransaction != null) {            mCurTransaction.commitAllowingStateLoss();//            if (manager != null)//                manager.executePendingTransactions();緣由：當FragmentManager add，attach，remove，dettach時若是fragment爲null，如add(null)則容易mCurTransaction.commitAllowingStateLoss（） 方法可能出現這個錯誤。解決方法：在執行這些方法時判斷fragment是否爲null。 如if(fragment != null) add(fragment);