利用旋轉實現時鐘(IOS)

 


- (void)viewDidLoad {
[super viewDidLoad];
self.secondHand.layer.anchorPoint = CGPointMake(.5, .9);
self.minuteHand.layer.anchorPoint = CGPointMake(.5, .9);
self.hourHand.layer.anchorPoint = CGPointMake(.5, .9);

self.timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(tick) userInfo:nil repeats:YES];
[self tick];
}

- (void)tick {
NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSUInteger units = NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;
NSDateComponents *components = [calendar components:units fromDate:[NSDate date]];
CGFloat hoursAngle = (components.hour / 12.0) *M_PI * 2.0;
CGFloat minsAngle = (components.minute / 60.0) * M_PI * 2.0;
CGFloat secsAngle = (components.second / 60.0) * M_PI * 2.0;

self.hourHand.transform = CGAffineTransformMakeRotation(hoursAngle);
self.minuteHand.transform = CGAffineTransformMakeRotation(minsAngle);
self.secondHand.transform = CGAffineTransformMakeRotation(secsAngle); }