BUG:
An instance 0x151dbfd20 of class XXX was deallocated while key value observers were still registered with it. Current observation info:( Context: 0x0, Property: 0x170859a40> )
對象釋放了但是沒有釋放他的KVO，當(dāng)時(shí)刷新UI時(shí)remove了一個(gè)設(shè)置KVO的視圖，需在設(shè)置KVO視圖remove前將觀察者移除掉术荤；[youView removeObserver:self forKeyPath:@"keyPath"];。當(dāng)控制器移除時(shí)也需要調(diào)移除觀察者每篷。- (void)dealloc{[youView removeObserver:self forKeyPath:@"keyPath"];}
