iOS 闪光的按钮，流光动画，iPhone经典滑动解锁动画

做一个类似于iPhone经典滑动解锁动画的发光按钮（流光）代码如下

//device screen size

#define kScreenWidth         [[UIScreen mainScreen] bounds].size.width

#define kScreenHeight        [[UIScreen mainScreen] bounds].size.height

#define RGB(r, g, b) [UIColor colorWithRed:r/255.0 green:g/255.0 blue:b/255.0 alpha:1]

#define RGBA(r, g, b, a) [UIColor colorWithRed:r/255.0 green:g/255.0 blue:b/255.0 alpha:a]

#define kColorTextDarkGray  RGB(100,100,100)   //稍深的灰色字体

#import "ViewController.h"

@interface ViewController ()

@property(nonatomic,strong)  CAGradientLayer *gradientLayer;

@end

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

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

    [self initView];

}

-(void)initView{

    UIView *tempView = [UIView new];

    [self.view addSubview:tempView];

    tempView.backgroundColor = [UIColor grayColor];

    tempView.frame = CGRectMake(16, 60, kScreenWidth-32, 44);

    

    UILabel *skipLabel = [[UILabel alloc] init];

    skipLabel.font = [UIFont systemFontOfSize:18];

    skipLabel.text = @"跳过 > ";

    skipLabel.textAlignment = NSTextAlignmentCenter;

    skipLabel.textColor = kColorTextDarkGray;

//    skipLabel.backgroundColor = [UIColor greenColor];

    skipLabel.frame = tempView.bounds;

    [tempView addSubview:skipLabel];

    

    CAGradientLayer *gradientLayer = [[CAGradientLayer alloc] init];

    self.gradientLayer = gradientLayer;

    gradientLayer.bounds = skipLabel.bounds;

    gradientLayer.position = skipLabel.center;

    gradientLayer.startPoint = CGPointMake(0, 0.5);

    gradientLayer.endPoint = CGPointMake(1, 0.5);

    

    NSMutableArray *colors = [NSMutableArray array];

    [colors addObject:(id)[UIColor blackColor].CGColor];

    [colors addObject:(id)[UIColor whiteColor].CGColor];

    [colors addObject:(id)[UIColor blackColor].CGColor];

    

    gradientLayer.colors = colors;

    gradientLayer.locations = @[@0.2, @0.5, @0.8];

    [tempView.layer addSublayer:gradientLayer];

    

    CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:@"locations"];

    anim.fromValue =  @[@0, @0, @0.3];

    anim.toValue = @[@0.7,@1,@1];

    anim.duration = 1.5;

    anim.repeatCount = HUGE;

    anim.removedOnCompletion = NO;

    [gradientLayer addAnimation:anim forKey:nil];

    gradientLayer.mask = skipLabel.layer;

    gradientLayer.masksToBounds = YES;

    

    UIButton *skipBtn = [[UIButton alloc] init];

    skipBtn.backgroundColor = [UIColor clearColor];

    [skipBtn addTarget:self action:@selector(skipBtnClicked) forControlEvents:UIControlEventTouchUpInside];

    [tempView addSubview:skipBtn];

    skipBtn.frame = tempView.bounds;

    

}

-(void)skipBtnClicked{

    NSLog(@"---点击我了---");

}