iOS 小小的加载动画

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {

[super viewDidLoad];

CAShapeLayer *bottomLayer = [CAShapeLayer layer];

bottomLayer.path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(100, 30, 100, 100) cornerRadius:100].CGPath;

bottomLayer.backgroundColor = [UIColor orangeColor].CGColor;

bottomLayer.lineWidth = 5;

bottomLayer.fillColor = [UIColor whiteColor].CGColor;

bottomLayer.strokeColor = [UIColor purpleColor].CGColor;

[self.view.layer addSublayer:bottomLayer];

CAShapeLayer *ovalShaper = [CAShapeLayer layer];

ovalShaper.path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(100, 100, 100, 100)].CGPath;

ovalShaper.lineCap = kCALineCapRound;

ovalShaper.path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(100, 30, 100, 100) cornerRadius:100].CGPath;

ovalShaper.fillColor = [UIColor whiteColor].CGColor;

ovalShaper.strokeColor = [UIColor redColor].CGColor;

ovalShaper.lineWidth = 5;

[self.view.layer addSublayer:ovalShaper];

CABasicAnimation *startAnimation = [CABasicAnimation animationWithKeyPath:@"strokeStart"];

startAnimation.fromValue = @(-1);

startAnimation.toValue = @(1.0);

CABasicAnimation *endAnimation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];

endAnimation.fromValue = @(0.0);

endAnimation.toValue = @(1);

//组合动画

CAAnimationGroup *group = [CAAnimationGroup animation];

group.animations = @[startAnimation,endAnimation];

group.duration = 1;

group.repeatCount = CGFLOAT_MAX;

group.fillMode = kCAFillModeForwards;

group.removedOnCompletion = NO;

[ovalShaper addAnimation:group forKey:nil];

}

@end