NSTime

    //第一种，自动触发定时器    {        NSTimer *time = [NSTimer scheduledTimerWithTimeInterval:10 target:self selector:@selector(t:) userInfo:@{@"sdfsdf":@"df"} repeats:YES];                NSTimer *time2 = [NSTimer scheduledTimerWithTimeInterval:10 target:self selector:@selector(t:) userInfo:@"sdfsdf" repeats:YES];        //这里是提前触发，不写也会在设定间隔时间触发        [time fire];        //对应的销毁函数//    [time invalidate];    }            //第二种，手动触发    {        NSTimer *time3 = [NSTimer timerWithTimeInterval:2 target:self selector:@selector(t:) userInfo:@"sdf" repeats:YES];        NSRunLoop *runloop=[NSRunLoop currentRunLoop];        [runloop addTimer:time3 forMode:NSDefaultRunLoopMode];    }            //第三种    {        //初始化一个Invocation对象        NSInvocation * invo = [NSInvocation invocationWithMethodSignature:[[self class] instanceMethodSignatureForSelector:@selector(init)]];        [invo setTarget:self];        [invo setSelector:@selector(t:)];        NSTimer * timer = [NSTimer timerWithTimeInterval:1 invocation:invo repeats:YES];        //加入主循环池中        [[NSRunLoop mainRunLoop]addTimer:timer forMode:NSDefaultRunLoopMode];        //开始循环        [timer fire];            }}-(void)t:(NSTimer*)n{    //传参数  NSNumber  字典  字符串    id  t = [n userInfo];        //触发的系统时间    NSData *d = n.fireDate;}