1、第一种方法
+ (NSTimer *)scheduledTimerWithTimeInterval:(NSTimeInterval)ti target:(id)aTarget selector:(SEL)aSelector userInfo:(id)userInfo repeats:(BOOL)yesOrNo;
2、第二种方法
NSThread *thread = [[NSThread alloc] initWithTarget:self selector:@selector(newThread) object:nil];
[thread start];
- (void)newThread
{
@autoreleasepool
{
[NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(addTime) userInfo:nil repeats:YES];
[[NSRunLoop currentRunLoop] run];
}
}
3、第三种方法
使用了GCD
dispatch_source_t _timers;
uint64_t interval = 0.01 * NSEC_PER_SEC;
dispatch_queue_t queue = dispatch_queue_create("my queue", 0);
_timers = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, queue);
dispatch_source_set_timer(_timers, dispatch_time(DISPATCH_TIME_NOW, 0), interval, 0);
__weak ViewController *blockSelf = self;
dispatch_source_set_event_handler(_timers, ^()
{
NSLog(@"Timer %@", [NSThread currentThread]);
[blockSelf addTime];
});
dispatch_resume(_timers);
然后再主线程刷新
dispatch_async(dispatch_get_main_queue(), ^{
self.label.text = [NSString stringWithFormat:@"%.2f", self.timeCount/100];
});
(以上内容摘自http://www.faceye.net/search/120004.html)