iOS UIView 开始旋转，暂停，继续旋转

• 先看下效果

  
  旋转.gif

首选封装个分类

#import <QuartzCore/QuartzCore.h>
#import <UIKit/UIKit.h>

NS_ASSUME_NONNULL_BEGIN

@interface CALayer (Category)
// 旋转
+(void) makeAnimation:(UIView *)view;
// 暂停
+(void)pauseLayer:(CALayer*)layer;
// 继续
+(void)resumeLayer:(CALayer*)layer;
@end

NS_ASSUME_NONNULL_END

#import "CALayer+Category.h"

@implementation CALayer (Category)

// 旋转
+(void) makeAnimation:(UIView *)view {
    CABasicAnimation *rotationAnimation;
    rotationAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
    rotationAnimation.removedOnCompletion = NO;
    rotationAnimation.toValue = [NSNumber numberWithFloat:M_PI*2.0];
    rotationAnimation.duration = 4;
    rotationAnimation.repeatCount = HUGE_VALF;
    [view.layer addAnimation:rotationAnimation forKey:@"rotationAnimation"];
}

// 暂停
+(void)pauseLayer:(CALayer*)layer
{
    CFTimeInterval pausedTime = [layer convertTime:CACurrentMediaTime() fromLayer:nil];
    layer.speed = 0.0;
    layer.timeOffset = pausedTime;
}

// 继续
+(void)resumeLayer:(CALayer*)layer
{
    CFTimeInterval pausedTime = [layer timeOffset];
    layer.speed = 1.0;
    layer.timeOffset = 0.0;
    layer.beginTime = 0.0;
    CFTimeInterval timeSincePause = [layer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;
    layer.beginTime = timeSincePause;
}


@end

使用

#import "ViewController.h"
#import "CALayer+Category.h"

@interface ViewController ()
@property (nonatomic, weak) UIView *v;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    UIView *v = [[UIView alloc] init];
    v.frame = CGRectMake(0, 0, 100, 100);
    v.center = self.view.center;
    v.backgroundColor = [UIColor redColor];
    [self.view addSubview:v];
    self.v = v;
    
    UIButton *a = [UIButton buttonWithType:UIButtonTypeSystem];
    a.frame = CGRectMake(v.frame.origin.x, CGRectGetMaxY(v.frame) + 30, 50, 30);
    [a setTitle:@"旋转" forState:UIControlStateNormal];
    [a addTarget:self action:@selector(aClick) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:a];
    
    UIButton *b = [UIButton buttonWithType:UIButtonTypeSystem];
    b.frame = CGRectMake(v.frame.origin.x, CGRectGetMaxY(a.frame) + 30, 50, 30);
    [b setTitle:@"暂停" forState:UIControlStateNormal];
    [b addTarget:self action:@selector(bClick) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:b];
    
    UIButton *c = [UIButton buttonWithType:UIButtonTypeSystem];
    c.frame = CGRectMake(v.frame.origin.x, CGRectGetMaxY(b.frame) + 30, 50, 30);
    [c setTitle:@"继续" forState:UIControlStateNormal];
    [c addTarget:self action:@selector(cClick) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:c];
    
}

// 旋转
- (void)aClick{
    [CALayer makeAnimation:self.v];
}

// 暂停
- (void)bClick{
    [CALayer pauseLayer:self.v.layer];
}

// 继续
- (void)cClick{
    [CALayer resumeLayer:self.v.layer];
}

@end

Demo见链接↓
https://gitee.com/shouny/rotating.git