iOs游戏中心-为比赛指定配置

仔细想想:在GKMatchRequest中的playerGoups可能是一个不错的选择。

   "If your application sets the playerGroup property, then only players whose 
requests share the same playerGroup value are automatched by Game Center. 
You can use any values you want for player groups. For example, 
you could define different playerGroup values to implement any of the 
following filters"

因为playerGroups是一个NSInteger,我应该可以用它来做我想做的事情。