问题描述
我正在将NSSNotifcation发送到iPhone应用程序中的另一个视图控制器，但是它的观察者方法收到两次通知，一个人怎么可能指导我
i am sending NSSNotifcation to another view controller in iPhone app but its observer method getting notified two times how its possible can any one guide me
我已使用此代码发布通知
i have use this code to post notification
[[NSNotificationCenter defaultCenter] postNotificationName:@"updateStatusOnFacebook" object:nil userInfo:nil];
并添加了观察者
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(postToWall) name:@"updateStatusOnFacebook" object:nil];
推荐答案
您是否两次添加了观察者?
Have you added the observer twice?
您要在哪个方法中调用addObserver:selector:object :?如果它在viewWillAppear中，则可能会多次调用.
Which method are you calling addObserver:selector:object: in? If it's in viewWillAppear then this might be called more than once.
您的方法将被调用与您添加观察者相同的次数.
Your method will be called the same number of times that you have added an observer.
尝试一下:
[[NSNotificationCenter defaultCenter] removeObserver:self name:@"updateStatusOnFacebook" object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(postToWall) name:@"updateStatusOnFacebook" object:nil];
另一个原因是您可能只发送了两次通知:)
The other reason is that you might just be sending the notification twice :)
这篇关于iPhone中的NSNotification的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！