Checking if NSTimer was added to NSRunLoop

Question

Let\'s say I\'m creating NSTimer in some place in the code and later, I want to add it to the mainRunLoop only if it wasn\'t already added before:

NSTimer* myTim         


        

Answer 1

Try this:

CFRunLoopRef loopRef = [[NSRunLoop mainRunLoop] getCFRunLoop];
BOOL timerAdded = CFRunLoopContainsTimer(loopRef, (CFRunLoopTimerRef)myTimer ,kCFRunLoopDefaultMode);

then check timerAdded variable

Answer 2

Yes; keep a reference to it in an instance variable and check for non-nil:

@interface MyClass() {
    NSTimer *_myTimer;
}
@end

...

if (!_myTimer)
{
    _myTimer = [NSTimer timerWithTimeInterval:1.0f
                                       target:self
                                     selector:@selector(targetMethod:)
                                     userInfo:nil
                                      repeats:YES];
    NSRunLoop *runLoop = [NSRunLoop mainRunLoop];
    [runLoop addTimer:_myTimer forMode:NSDefaultRunLoopMode];
}