POP的Stroke动画

效果

源码

https://github.com/YouXianMing/Animations

//
//  PopStrokeController.m
//  Animations
//
//  Created by YouXianMing on 15/11/17.
//  Copyright © 2015年 YouXianMing. All rights reserved.
//

#import "PopStrokeController.h"
#import "GCD.h"
#import "POP.h"
#import "StrokeCircleLayerConfigure.h"

@interface PopStrokeController ()

@property (nonatomic, strong) CAShapeLayer  *circleShape;
@property (nonatomic, strong) GCDTimer      *timer;

@end

@implementation PopStrokeController

- (void)viewDidLoad {

    [super viewDidLoad];
}

- (void)setup {

    [super setup];

    self.circleShape = [CAShapeLayer layer];
    self.circleShape.strokeEnd = 0.f;
    self.circleShape.lineCap   = kCALineCapRound;
    StrokeCircleLayerConfigure *config = [StrokeCircleLayerConfigure new];
    config.lineWidth    = 4.f;
    config.startAngle   = 0;
    config.endAngle     = M_PI * 2;
    config.radius       = 55.f;
    config.circleCenter = self.view.center;
    config.strokeColor  = [UIColor cyanColor];
    [config configCAShapeLayer:self.circleShape];
    [self.view.layer addSublayer:self.circleShape];

    _timer = [[GCDTimer alloc] initInQueue:[GCDQueue mainQueue]];

    [_timer event:^{

        CGFloat value1 = arc4random() % 101 / 100.f;
        CGFloat value2 = arc4random() % 101 / 100.f;

        POPSpringAnimation *strokeAnimationEnd = [POPSpringAnimation animationWithPropertyNamed:kPOPShapeLayerStrokeEnd];
        strokeAnimationEnd.toValue             = @(value1 > value2 ? value1 : value2);
        strokeAnimationEnd.springBounciness    = 12.f;

        POPSpringAnimation *strokeAnimationStart = [POPSpringAnimation animationWithPropertyNamed:kPOPShapeLayerStrokeStart];
        strokeAnimationStart.toValue             = @(value1 < value2 ? value1 : value2);
        strokeAnimationStart.springBounciness    = 12.f;

        POPBasicAnimation *strokeAnimationColor  = [POPBasicAnimation animationWithPropertyNamed:kPOPShapeLayerStrokeColor];
        strokeAnimationColor.toValue             = (__bridge id)([self randomColor].CGColor);

        [self.circleShape pop_addAnimation:strokeAnimationEnd forKey:@"layerStrokeAnimation"];
        [self.circleShape pop_addAnimation:strokeAnimationStart forKey:@"layerStrokeAnimation1"];
        [self.circleShape pop_addAnimation:strokeAnimationColor forKey:@"layerStrokeAnimation2"];

    } timeIntervalWithSecs:1];

    [_timer start];
}

- (UIColor *)randomColor {

    return [UIColor colorWithRed:arc4random() % 101 / 100.f
                           green:arc4random() % 101 / 100.f
                            blue:arc4random() % 101 / 100.f
                           alpha:1];
}

@end

细节