iPhone中的NSNotification [英] NSNotification in iphone

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];

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另一个原因是您可能只发送了两次通知:)

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The other reason is that you might just be sending the notification twice :)

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