解决IllegalStateException: Can not perform this action after onSaveInstanceState

错误信息：

java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState

at android.support.v4.app.FragmentManagerImpl.checkStateLoss(FragmentManager.java:1489)
at android.support.v4.app.FragmentManagerImpl.enqueueAction(FragmentManager.java:1507)
at android.support.v4.app.BackStackRecord.commitInternal(BackStackRecord.java:634)
at android.support.v4.app.BackStackRecord.commit(BackStackRecord.java:613)
at com.zte.iptvclient.android.iptvclient.activity.MainFragmentActivity.a(MainFragmentActivity.java:2137)
at com.zte.iptvclient.android.iptvclient.activity.MainFragmentActivity.a(MainFragmentActivity.java:2297)
at com.zte.iptvclient.android.iptvclient.activity.MainFragmentActivity.a(MainFragmentActivity.java:2230)
at com.zte.iptvclient.android.iptvclient.activity.MainFragmentActivity.a(MainFragmentActivity.java:2937)
at com.zte.iptvclient.android.baseclient.f.f.j.q(LoginImplement.java:1845)
at com.zte.iptvclient.android.baseclient.f.f.j.c(LoginImplement.java:75)
at com.zte.iptvclient.android.baseclient.f.f.k.a(LoginImplement.java:308)
at com.zte.iptvclient.android.androidsdk.uiframe.j.b(CommonListDataLoader.java:10355)
at com.zte.iptvclient.android.androidsdk.uiframe.k.handleMessage(CommonListDataLoader.java:206)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5669)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:960)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)

代码：

FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();

if (fragment.isAdded())
{
Log.w(LOG_TAG, fragment.getFragmentTitle() + "fragment is added.");
//return;
fragmentTransaction.remove(fragment);
}

setTitle(fragment.getFragmentTitle());

fragmentTransaction.replace(R.id.main_fragment_container, fragment, tag);

fragmentTransaction.commit();  ---  这一行报错

不合法原因：

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.

   大致意思是说我使用的 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。

解决方法：
将这个方法  fragmentTransaction.commit(); 替换

public abstract int commitAllowingStateLoss ()   
       其效果是一样的。