1，延时执行（不可重复）

 

[objc] view plain copy/**  ** delay 不可重复  **/  - (void)timerMethodA  {      [self performSelector:@selector(methodAEvent)                 withObject:nil                 afterDelay:2.0f];//延时时间  }    - (void)methodAEvent  {      NSLog(@"-- method_A");  }

 

 

效果我直接截取控制台的日志了，就不做UI了。

 

2，用NSTimer执行定时和延时（可重复）

 

[objc] view plain copy/**  ** timer 可重复  **/  - (void)timerMethodB  {      _timer = [NSTimer scheduledTimerWithTimeInterval:1.0f  //间隔时间                                                target:self                                              selector:@selector(methodBEvnet)                                              userInfo:nil                                               repeats:YES];  }    - (void)methodBEvnet  {      count++;      NSLog(@"-- Method_B count: %d", count);            if (count >= 5) {          [_timer invalidate];    //重复5次，timer停止          NSLog(@"-- end");      }  }

 

 

 

 

3，用dispatch_source_set_timer执行定时（可重复）

 

[objc] view plain copy/**  ** dispatch_time 可重复  **/  - (void)timerMethodC  {      __block int i = 0;      CGFloat duration = 1.0f;   //间隔时间      dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);      dispatch_source_t timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, queue);            dispatch_source_set_timer(timer, DISPATCH_TIME_NOW, duration * NSEC_PER_SEC, 0);      dispatch_source_set_event_handler(timer, ^{                    i++;          if (i > 5) {              dispatch_source_cancel(timer);  //执行5次后停止              NSLog(@"-- end");          }else{              NSLog(@"-- Method_C i:%d", i);          }      });      dispatch_resume(timer);  }

 

 

 

 

4，用dispatch_after执行延时（不可重复）

 

[objc] view plain copy/**  ** dispatch_time 不可重复  **/  - (void)timerMethodD  {      CGFloat delayTime = 2.0f;   //延时时间      dispatch_time_t timer = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayTime *NSEC_PER_SEC));      dispatch_after(timer, dispatch_get_main_queue(), ^{          NSLog(@"-- Method_D time:%@", [NSDate date]);      });                                              }

 

 

 

 

文章最后奉上demo