Use the Fragment app to place the background for a long time, be recycled by the system, appear crash

Use the fragment application to place the background for a long time, the system is recycled, appear crash;
Reason: The system made the source Fragmentactivity call Onsaveinstancestate Save Fragment object,
At this time the system recovers the saved fragment, but when fragmentactivity re-executes the life cycle,
We re-generated the fragment object attached to the fragmentactivity, the system resumed fragment and the Activity Lost Association, error;
Processing: Method 1. OnCreate method in fragmentactivity to Judge Savedinstancestate==null to generate new fragment;
Method 2: Rewrite the Onsaveinstancestate method in fragmentactivity, but do not implement;

SOURCE Fragmentactivity
protected void Onsaveinstancestate (Bundle outstate)
{
Super.onsaveinstancestate (outstate);
Parcelable p = this.mFragments.saveAllState ();
if (P! = null)
Outstate.putparcelable ("Android:support:fragments", p);
}

Use the Fragment app to place the background for a long time, be recycled by the system, appear crash