获得NSTimer目标的返回值

NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:1.0
                                                      target:self
                                                    selector:@selector(timerFired:)
                                                    userInfo:nil
                                                     repeats:YES];

- (void)timerFired:(NSTimer *)timer {
    // 在这里编写你要执行的代码
}