"iOS Basics" Nstimer timer use

1. Statement

Nstimer *timer;

2. Definition

Timer = [Nstimerscheduledtimerwithtimeinterval:1.0ftarget:selfselector: @selector (updatevalue) userinfo:nilrepeats : YES];

The following is the calling function

-(void) Updatevalue

{

NSLog (@ "Hello Timer");

}

3. Turn on the timer

-(void) Viewwillappear: (BOOL) animated

{

Open Timer

[Timer Setfiredate:[nsdatedistantpast]];

}

4. Turn off the timer

-(void) Viewdiddisappear: (BOOL) animated

{

Turn off the timer

[Timer setfiredate:[nsdatedistantfuture]];

}

Here's another GCD timer method:

1. Statement

dispatch_source_t _timer;

2. Define Use

__weakid weakself =self;

Double Delayinsecond = 0.25;

_timer =dispatch_source_create (dispatch_source_type_timer, 0, 0,dispatch_get_main_queue ());

Dispatch_source_set_timer (_timer,dispatch_walltime (NULL, 0), (unsigned) (Delayinsecond *nsec_per_sec), 0);

Dispatch_source_set_event_handler (_timer, ^{[weakselfupdatevalues];});

Open

Dispatch_resume (_timer);

-(void) updatevalues

{

NSLog (@ "Hello Timer");

}

3. Release

Dispatch_source_cancel (_timer);

Dispatch_release (_timer);

"iOS Basics" Nstimer timer use