iOS边练边学--CALayer，非根层隐式动画，钟表练习

  1 #import "ViewController.h"
  2 // 通过秒数计算秒针转过的角度
  3 #define secondRotation(second) ((second * 6) / 180.0 * M_PI)
  4 // 通过分数计算分针转过的角度
  5 #define minuteRotation(minute) ((minute * 6) / 180.0 * M_PI)
  6 // 通过时数计算时针转过的角度
  7 #define hourRotation(hour) ((hour * 30) / 180.0 * M_PI)
  8 
  9 @interface ViewController ()
 10 @property (weak, nonatomic) IBOutlet UIImageView *clockView;
 11 /** second */
 12 @property(nonatomic,strong) CALayer *secondL;
 13 /** minute */
 14 @property(nonatomic,strong) CALayer *minuteL;
 15 /** hour */
 16 @property(nonatomic,strong) CALayer *hourL;
 17 @end
 18 
 19 @implementation ViewController
 20 
 21 - (void)viewDidLoad {
 22     [super viewDidLoad];
 23     
 24     // 添加秒针
 25     [self setUpSecondLayer];
 26     
 27     // 添加时针
 28     [self setUpHourLayer];
 29     
 30     // 添加分针
 31     [self setUpMinuteLayer];
 32     [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(timeChange) userInfo:nil repeats:YES];
 33     [self timeChange];
 34 }
 35 
 36 - (void)timeChange
 37 {
 38     // 获取当前时间，通过秒数计算秒针的旋转弧度
 39     // 当前的日历对象，从日历对象中获取时间组件
 40     NSCalendar *calendar = [NSCalendar currentCalendar];
 41     
 42     // 日历组件包含了：年月日时分秒等
 43     // 经验：以后枚举中有移位运算符，通常可以使用并运算（|）
 44     NSDateComponents *compontent = [calendar components:NSCalendarUnitSecond | NSCalendarUnitMinute | NSCalendarUnitHour fromDate:[NSDate date]];
 45     
 46     NSInteger second = compontent.second;
 47     NSInteger minute = compontent.minute;
 48     NSInteger hour = compontent.hour;
 49     
 50     _hourL.transform = CATransform3DMakeRotation(hourRotation(hour) + minuteRotation(minute) / 12, 0, 0, 1);
 51     _minuteL.transform = CATransform3DMakeRotation(minuteRotation(minute) + secondRotation(second) / 60, 0, 0, 1);
 52     _secondL.transform = CATransform3DMakeRotation(secondRotation(second), 0, 0, 1);
 53 
 54 }
 55 
 56 - (void)setUpHourLayer
 57 {
 58     // 获取钟表的宽高
 59     CGFloat clockWH = _clockView.frame.size.height * 0.5;
 60     // 创建时针的图层
 61     CALayer *hourL = [CALayer layer];
 62     hourL.bounds = CGRectMake(0, 0, 6, clockWH - 40);
 63     hourL.backgroundColor = [UIColor blackColor].CGColor;
 64     hourL.position = CGPointMake(clockWH, clockWH);
 65     hourL.anchorPoint = CGPointMake(0.5, 1);
 66     hourL.cornerRadius = 3;
 67     
 68     [_clockView.layer addSublayer:hourL];
 69     _hourL = hourL;
 70 }
 71 
 72 - (void)setUpMinuteLayer
 73 {
 74     // 获取钟表的宽高
 75     CGFloat clockWH = _clockView.frame.size.height * 0.5;
 76     // 创建分针的图层
 77     CALayer *minuteL = [CALayer layer];
 78     minuteL.bounds = CGRectMake(0, 0, 6, clockWH - 30);
 79     minuteL.backgroundColor = [UIColor blackColor].CGColor;
 80     minuteL.position = CGPointMake(clockWH, clockWH);
 81     minuteL.anchorPoint = CGPointMake(0.5, 1);
 82     minuteL.cornerRadius = 3;
 83     
 84     [_clockView.layer addSublayer:minuteL];
 85     _minuteL = minuteL;
 86 }
 87 
 88 - (void)setUpSecondLayer
 89 {
 90     // 获取钟表的宽高
 91     CGFloat clockWH = _clockView.frame.size.height * 0.5;
 92     // 创建秒针的图层
 93     CALayer *secondL = [CALayer layer];
 94     secondL.bounds = CGRectMake(0, 0, 2, clockWH - 20);
 95     secondL.backgroundColor = [UIColor redColor].CGColor;
 96     secondL.position = CGPointMake(clockWH, clockWH);
 97     secondL.anchorPoint = CGPointMake(0.5, 1);
 98     
 99     [_clockView.layer addSublayer:secondL];
100     _secondL = secondL;
101 }
102 
103 - (void)didReceiveMemoryWarning {
104     [super didReceiveMemoryWarning];
105     // Dispose of any resources that can be recreated.
106 }
107 
108 @end