Invalidate NSTimer bas access - objective-c

Question

I'm trying to implement a timer but i'm getting bad access...I didn't use release neither in dealloc.
.h
NSTimer *_timerAnimacao;
#property (nonatomic, retain) NSTimer *timerAnimacao;
.m
#synthesize timerAnimacao = _timerAnimacao;
Here is where I call the timer.
if(acondition)
_timerAnimacao = [NSTimer scheduledTimerWithTimeInterval:0.06 target:self selector:#selector(changeTimeFilter:) userInfo:nil repeats:YES];
else
_timerAnimacao = [NSTimer scheduledTimerWithTimeInterval:0.06 target:self selector:#selector(changeTimeFilterHide:) userInfo:nil repeats:YES];
the changeTimeFilter works fine...but changeTimeFilterHide is getting BAD Access.
-(void)changeTimeFilter:(NSTimer *)theTimer{
if (tAnimacaoFilter<5) {
[_tbFilters setFrame:CGRectMake(_tbFilters.frame.origin.x, _tbFilters.frame.origin.y, _tbFilters.frame.size.width, 58*tAnimacaoFilter)];
}
if(tAnimacaoFilter < 10) {
tAnimacaoFilter++;
[_tbFeeds setFrame:CGRectMake(_tbFeeds.frame.origin.x, _tbFeeds.frame.origin.y + (4.4*tAnimacaoFilter), _tbFeeds.frame.size.width, _tbFeeds.frame.size.height - (4.4*tAnimacaoFilter))];
[imgBordaTbDireita setFrame:CGRectMake(imgBordaTbDireita.frame.origin.x, _tbFeeds.frame.origin.y - 4, imgBordaTbDireita.frame.size.width, imgBordaTbDireita.frame.size.height)];
[imgBordaTbEsquerda setFrame:CGRectMake(imgBordaTbEsquerda.frame.origin.x, _tbFeeds.frame.origin.y, imgBordaTbEsquerda.frame.size.width, imgBordaTbEsquerda.frame.size.height)];
}
else {
if(_timerAnimacao)
[_timerAnimacao invalidate];
[btnFilter setEnabled:YES];
}
}
-(void)changeTimeFilterHide:(NSTimer *)theTimer{
if (tAnimacaoFilter<5) {
[_tbFilters setFrame:CGRectMake(_tbFilters.frame.origin.x, _tbFilters.frame.origin.y, _tbFilters.frame.size.width, (58*5) - (58*tAnimacaoFilter))];
}
if(tAnimacaoFilter < 10) {
tAnimacaoFilter++;
[_tbFeeds setFrame:CGRectMake(_tbFeeds.frame.origin.x, _tbFeeds.frame.origin.y - (4.4*tAnimacaoFilter), _tbFeeds.frame.size.width, _tbFeeds.frame.size.height + (4.4*tAnimacaoFilter))];
[imgBordaTbDireita setFrame:CGRectMake(imgBordaTbDireita.frame.origin.x, _tbFeeds.frame.origin.y - 4, imgBordaTbDireita.frame.size.width, imgBordaTbDireita.frame.size.height)];
[imgBordaTbEsquerda setFrame:CGRectMake(imgBordaTbEsquerda.frame.origin.x, _tbFeeds.frame.origin.y, imgBordaTbEsquerda.frame.size.width, imgBordaTbEsquerda.frame.size.height)];
}
else {
if(_timerAnimacao)
[_timerAnimacao invalidate];
[btnFilter setEnabled:YES];
}
}

Answer 1

What you need to do on invalidate is to set NSTimer to nil like this:
[_timerAnimacao invalidate];
_timerAnimacao = nil;
If you don't do it your next commands will not work properly, e.g.:
if(_timerAnimacao)
[_timerAnimacao invalidate];
Please note: if(_timerAnimacao) is the same like if(_timerAnimacao == nil) !
Take a look at this one as well: How do I use NSTimer?

Answer 2

The instance of NSTimer needs to be in memory while you start and invalidate.
You can do that in two ways:
Set the NSTimer as a property of Appdelegate class, and use it wherever you need to.
NSTimer *timer=[(MyAppDelegate *)[[UIApplication sharedApplication] delegate].timer;
Create a new class and set NStimer as a property. Create a class method to return a singleton instance of the class.
static MyClass *obj = NULL;
(MyClass *)instance
{
#synchronized(self)
{
if (obj == NULL)
obj = [[self alloc] init];
}
return(obj);
}
I would prefer the second method.