360旋转动画

#import "ViewController.h"

@interface ViewController ()

@property (weak, nonatomic) IBOutlet UIButton *btn;

@end

@implementation ViewController

- (void)viewDidLoad {

[super viewDidLoad];

// Do any additional setup after loading the view, typically from a nib.

[_btn.layer removeAnimationForKey:@"rotation"];

CABasicAnimation *animation = [[CABasicAnimation alloc] init];

animation.fromValue = @(0);

animation.toValue = @(M_PI * 2);

animation.duration = 30;

animation.keyPath = @"transform.rotation.z";

animation.repeatCount = NSIntegerMax;

animation.removedOnCompletion = NO;

[_btn.layer addAnimation:animation forKey:@"rotation"];

}

- (void)didReceiveMemoryWarning {

[super didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

- (IBAction)click:(UIButton *)sender {

// 更改按钮的播放状态

sender.selected = !sender.selected;

if (sender.selected) {

[sender setTitle:@"暂停" forState:UIControlStateNormal];

[self pauseAnimate];

} else {

[sender setTitle:@"开始" forState:UIControlStateNormal];

[self resumeAnimate];

}

}

//暂停动画

- (void)pauseAnimate

{

CFTimeInterval pausedTime = [_btn.layer convertTime:CACurrentMediaTime() fromLayer:nil];

_btn.layer.speed = 0.0;

_btn.layer.timeOffset = pausedTime;

}

//恢复动画

- (void)resumeAnimate

{

CFTimeInterval pausedTime = [_btn.layer timeOffset];

_btn.layer.speed = 1.0;

_btn.layer.timeOffset = 0.0;

_btn.layer.beginTime = 0.0;

CFTimeInterval timeSincePause = [_btn.layer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;

_btn.layer.beginTime = timeSincePause;

}