Question

In ios5.0 with ARC, in my rootviewcontroller I call a method in a security manager object that is held by the app delegate. In that method I setup the timer as below

NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:5.0 target:self 
                                       selector:@selector(updateModel:) userInfo:str repeats:YES];
[[NSRunLoop currentRunLoop] addTimer:timer forMode:NSRunLoopCommonModes]; 

However, this never fires the selector ie. updateModel: never gets called. What may be wrong? Is there another more efficient way I can do this without using NStimer?

Answer 1

You seem to be a bit mixed up with your timer variable.

You initialize a new timer but you aren’t actually using it. Do you want to use the timer you initialized or do you want to you ApplicationDelegate.timer?

Here are the two possible solutions.

Option One (assuming that you have a class instance titled ApplicationDelegate and that it has a timer property):

ApplicationDelegate.timer = [NSTimer scheduledTimerWithTimeInterval:5.0 target:self selector:@selector(updateModel:) userInfo:str repeats:YES];
[[NSRunLoop currentRunLoop] addTimer:ApplicationDelegate.timer forMode:NSRunLoopCommonModes];

Option Two:

NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:5.0 target:self selector:@selector(updateModel:) userInfo:str repeats:YES];
[[NSRunLoop currentRunLoop] addTimer:timer forMode:NSRunLoopCommonModes];