解决IllegalStateException: Can not perform this action after onSaveInstanceState
今天使用Fragment的时候，出现了这个错误 IllegalStateException: Can not perform this action after onSaveInstanceState。
问题是在使用FragmentTransition的 commit方法添加一个Fragment的时候出现的，官网(https://developer.android.com/reference/android/app/FragmentTransaction.html#commitAllowingStateLoss())中有如下说明：
- commit
added in API level 11
int commit ()
Schedules a commit of this transaction. The commit does not happen immediately; it will be scheduled as work on the main thread to be done the next time that thread is ready.
A transaction can only be committed with this method prior to its containing activity saving its state. If the commit is attempted after that point, an exception will be thrown. This is because the state after the commit can be lost if the activity needs to be restored from its state. See
commitAllowingStateLoss()for situations where it may be okay to lose the commit.
| Returns | |
|---|---|
int | Returns the identifier of this transaction’s back stack entry, if addToBackStack(String) had been called. Otherwise, returns a negative number. |
commitAllowingStateLoss
added in API level 11
int commitAllowingStateLoss ()Like
commit()but allows the commit to be executed after an activity’s state is saved. This is dangerous because the commit can be lost if the activity needs to later be restored from its state, so this should only be used for cases where it is okay for the UI state to change unexpectedly on the user.Returns int
大致意思是说使用的 commit方法是在Activity的onSaveInstanceState()之后调用的，这样会出错，因为onSaveInstanceState
方法是在该Activity即将被销毁前调用，来保存Activity数据的，如果在保存玩状态后再给它添加Fragment就会出错。解决办法就
是把commit（）方法替换成 commitAllowingStateLoss()就行了，其效果是一样的。
