Nstimer retain its target.

A class object B has been released today (there is a timer in this class), and according to the principle of arc, the retaincount of B is 0 o'clock and the dealloc is called. But when the b=nil for me, did not enter the Dealloc.

-(void) dealloc

{

[Timer invalidate];

Timer = nil;

}

Later, after a friend reminded that Nstimer to the Class B has a reference, that is, at the initialization of the target has retain.

Timer = [Nstimer scheduledtimerwithtimeinterval:1.0 self selector: @selector (logout:) Userinfo:nil Repeats:yes];

Later changed self to __weak, found also not.

__weak id weakself = self;

Timer = [Nstimer scheduledtimerwithtimeinterval:1.0 target:weakself selector: @selector (logout:) Userinfo:nil repeats: YES];

Finally, a method of using proxies was found in StackOverflow.

Http://stackoverflow.com/questions/16821736/weak-reference-to-nstimer-target-to-prevent-retain-cycle

Create a separate Weaktimertarget

@interface Weaktimertarget:nsobject

{

__weak ID target;

SEL selector;

}

-(ID) Initwithtarget: (ID) TG selector: (SEL) sel;

-(void) Timerdidfire: (Nstimer *) timer;

@end

@implementation Weaktimertarget

-(ID) Initwithtarget: (ID) TG selector: (SEL) SEL

{

self = [super init];

target = TG;

selector = sel;

return self;

}

-(void) Timerdidfire: (Nstimer *) timer

{

if (target)

{

[Target Performselector:selector Withobject:timer];

}

Else

{

[Timer invalidate];

}

}

@end

This is used in class B:

Weaktimertarget *weaktarget = [[Weaktimertarget alloc] initwithtarget:self selector: @selector (logout:)];

[Nstimer scheduledtimerwithtimeinterval:1.0 target:weaktarget selector: @selector (timerdidfire:) userinfo:nil Repeats:yes];

This will solve the problem of not releasing memory, but why use __weak self and __strong self effect is the same do not know why, I hope you can advise.

Nstimer retain its target.