无法删除观察员<MKUserTrackingBarButtonItem

Question

- (void)viewWillAppear:(BOOL)animated 
{ 
MKUserTrackingBarButtonItem *trackingBarButtonItem = [[MKUserTrackingBarButtonItem alloc]initWithMapView:_mapView]; 

NSArray *barButtonItems = [NSArray arrayWithObjects:trackingBarButtonItem, nil]; 
mapToolbar.items = barButtonItems; 
... 
} 

代码工作在iPhone上正常，但在iPad上，当视图卸载我得到一个错误：

Cannot remove an observer <MKUserTrackingBarButtonItem 0x9cc0930> for the key path 
"controlSize" from <UIButton 0x991b420> because it is not registered as an observer.' 

Answer 1

我接触苹果DTS和他们的回答是：

“据我所知，在当前的运输SDK中没有解决这个问题的方法，但我会检查最新的iOS SDK测试版，看看它是否仍然是个问题。”