iOS开发 --滑动来解锁 >> 动效

#import "ViewController.h"
#import "UIView+MJExtension.h"

@interface ViewController ()

@property (nonatomic, strong) CAGradientLayer *gradientLayer;
@property (nonatomic, strong) NSArray *colors;
@property (nonatomic, strong) UILabel *unlock;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.navigationController.navigationBarHidden = YES;
    
    self.view.backgroundColor = [UIColor grayColor];
    // 渐变Layer
    CAGradientLayer *gradientLayer = [CAGradientLayer layer];
    [self.view.layer addSublayer:gradientLayer];
    gradientLayer.frame = CGRectMake(0, 200, self.view.mj_width, 64);
    gradientLayer.colors = @[
        (__bridge id)[UIColor blackColor].CGColor,
        (__bridge id)[UIColor whiteColor].CGColor,
        (__bridge id)[UIColor blackColor].CGColor,
    ];
    gradientLayer.locations = @[@0.25,@0.5,@0.75];
    gradientLayer.startPoint = CGPointMake(0, 0.5);
    gradientLayer.endPoint = CGPointMake(1, 0.5);
    
    CABasicAnimation *basicAnimation = [CABasicAnimation animationWithKeyPath:@"locations"];
    basicAnimation.fromValue = @[@0, @0, @0.25];
    basicAnimation.toValue = @[@0.75, @1, @1];
    basicAnimation.duration = 2.5;
    basicAnimation.repeatCount = HUGE;
    [gradientLayer addAnimation:basicAnimation forKey:nil];
    
    UILabel *unlock = [[UILabel alloc] initWithFrame:gradientLayer.bounds];
    self.unlock = unlock;
    unlock.alpha = 0.5;
    unlock.text = @"滑动来解锁 >>";
    unlock.textAlignment = NSTextAlignmentCenter;
    unlock.font = [UIFont boldSystemFontOfSize:30];
    gradientLayer.mask = unlock.layer;
}

@end