ios的延迟执行的方法

01     @implementation NSObject (PerformBlockAfterDelay)
02      
03     - (void)performBlock:(void (^)(void))block
04               afterDelay:(NSTimeInterval)delay
05     {
06         block = [[block copy] autorelease];
07         [self performSelector:@selector(fireBlockAfterDelay:)
08                    withObject:block
09                    afterDelay:delay];
10     }
11      
12     - (void)fireBlockAfterDelay:(void (^)(void))block {
13         block();
14     }
15      
16     @end

1 dispatch_after(dispatch_time(DISPATCH_TIME_NOW, NSEC_PER_SEC*1), dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
2                         dispatch_async(dispatch_get_main_queue(), ^{
3                             [self alertLabelWithStr:@"计划同步成功"];//执行的方法
4                         });
5                     });

1     [UIView animateWithDuration:0.0 delay:5.0 options:UIViewAnimationOptionAllowUserInteraction animations:^{
2     } completion:^(BOOL finished) {
3         //do stuff here
4     }];

1     [[NSOperationQueue mainQueue] addOperationWithBlock:aBlock];