CALayer时钟走动

#import "ViewController.h"

#define angleToRadio(angle) ((angle) * M_PI / 180.0)
#define perSecA 6//每一秒旋转6度
#define perMinA 6//每一分旋转6度
#define perHourA 30//每一小时旋转 30 度
#define  perMinHourA 0.5//每一分时针旋转多少度 0.5

@interface ViewController ()

@property (strong, nonatomic) UIImageView *clockImageView;
@property (strong, nonatomic) CALayer *secondLayer;
@property (strong, nonatomic) CALayer *minuteLayer;
@property (strong, nonatomic) CALayer *hourLayer;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    [self.view addSubview:self.clockImageView];//所有的旋转,缩放都是绕着锚点进行的.
    [self.clockImageView.layer addSublayer:self.secondLayer];//添加时针
    [self.clockImageView.layer addSublayer:self.minuteLayer];//添加分针
    [self.clockImageView.layer addSublayer:self.hourLayer];//添加秒针
    
    [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(timeChange) userInfo:nil repeats:YES];
    [self timeChange];//添加定时器
}

- (void)timeChange {
    //让秒针开始旋转
    //获取当前的秒数
    //获取当前的日历
    NSCalendar *calendar = [NSCalendar currentCalendar];
    //从什么时间获取日历当中的哪些组件(年,月,日,时,分,秒)
    NSDateComponents *dateComponents = [calendar components:NSCalendarUnitSecond | NSCalendarUnitMinute | NSCalendarUnitHour fromDate:[NSDate date]];
    //当前时间的秒数
    NSInteger curSecond = dateComponents.second;
    NSInteger curMinute = dateComponents.minute;
    NSInteger curHour = dateComponents.hour;
    NSLog(@"%ld-%ld-%ld",curHour,curMinute,curSecond);
    
    //求角度 = 当前的秒数 * 每一秒旋转多少度
    CGFloat secA = curSecond * perSecA;
    self.secondLayer.transform = CATransform3DMakeRotation(angleToRadio(secA), 0, 0, 1);
    
    //旋转分针
    //求角度 = 当前多少分 * 每一分旋转多少度
    CGFloat minA = curMinute * perMinA;
    self.minuteLayer.transform =  CATransform3DMakeRotation(angleToRadio(minA), 0, 0, 1);
    
    //旋转时针
    //求角度 = 当前多少小时 * 每一小时旋转多少度
    CGFloat hourA = curHour * perHourA + curMinute * perMinHourA;
    self.hourLayer.transform =  CATransform3DMakeRotation(angleToRadio(hourA), 0, 0, 1);
}

- (UIImageView *)clockImageView {
    if (!_clockImageView) {
        _clockImageView = [[UIImageView alloc] init];
        _clockImageView.frame = CGRectMake(100, 100, 200, 200);
        _clockImageView.contentMode = UIViewContentModeScaleAspectFit;
        _clockImageView.image = [UIImage imageNamed:@"clock"];
        _clockImageView.backgroundColor = [[UIColor redColor] colorWithAlphaComponent:0.3];
    }
    return _clockImageView;
}

- (CALayer *)secondLayer {
    if (!_secondLayer) {
        _secondLayer = [CALayer layer];
        _secondLayer.backgroundColor = [UIColor redColor].CGColor;
        _secondLayer.bounds = CGRectMake(0, 0, 1, 80);
        _secondLayer.anchorPoint = CGPointMake(0.5, 1);
        _secondLayer.position = CGPointMake(self.clockImageView.bounds.size.width * 0.5, self.clockImageView.bounds.size.height * 0.5);
    }
    return _secondLayer;
}

- (CALayer *)minuteLayer {
    if (!_minuteLayer) {
        _minuteLayer = [CALayer layer];
        _minuteLayer.backgroundColor = [UIColor blackColor].CGColor;
        _minuteLayer.bounds = CGRectMake(0, 0, 2, 70);
        _minuteLayer.anchorPoint = CGPointMake(0.5, 1);
        _minuteLayer.position = CGPointMake(self.clockImageView.bounds.size.width * 0.5, self.clockImageView.bounds.size.height * 0.5);
    }
    return _minuteLayer;
}

- (CALayer *)hourLayer {
    if (!_hourLayer) {
        _hourLayer = [CALayer layer];
        _hourLayer.backgroundColor = [UIColor blackColor].CGColor;
        _hourLayer.bounds = CGRectMake(0, 0, 3, 60);
        _hourLayer.anchorPoint = CGPointMake(0.5, 1);
        _hourLayer.position = CGPointMake(self.clockImageView.bounds.size.width * 0.5, self.clockImageView.bounds.size.height * 0.5);
    }
    return _hourLayer;
}

@end