NSNotificationCenter notifications not recieved by UIView subclass

Question

I've used NSNotificationCenter for application-wide messaging before but today I found a strange loophole. Working on a client's project there are a few UIView subclasses that will need to receive NSNotifications that I am already posting/receiving elsewhere in the app.

I'm calling addObserver:self from the init method and using #defined constants for the notification name. When the notification I registered to receive gets posted every other object that is listening (all UIViewController subclasses) gets the notification except for my UIView subclass.

Has anyone used NSNotificationCenter from within a UIView subclass successfully? I've tried breakpoints and NSLogs but my @selector is never getting called.

EDIT- The view was being created with loadNibNamed: and initWithCoder: wasn't implemented in the class. Registering for notification inside initWithCoder: works great.

I've used NSNotificationCenter with a UIView subclass successfully before. When you instantiate the UIView subclass are you calling init or initWithFrame? — hgwhittle
Would you mind posting the code (your -init override, the notification constants, and your handler method) that you use? — Tim

Gavin Gavin · Accepted Answer · 2014-01-02T20:32:27

Make sure the particular init method you implemented is getting called. Setting a break point at the spot you're registering for the notification will let you see if it gets hit or not. Sometimes when there are multiple init methods for a class, not all of them will get called depending on how it is getting initialized. For example, a UIViewController will call a different init method if you create an instance programmatically vs if you get one out of a storyboard.

NSNotificationCenter notifications not recieved by UIView subclass

2 Answers