CAGradientLayer实现向右滑动解锁的动画效果

    //bgView

    UIView *bottomView = [[UIView alloc] initWithFrame:CGRectMake(0.0f, self.view.height-120.0f, self.view.width, 60.0f)];

    bottomView.backgroundColor = [UIColor grayColor];

    [self.view addSubview:bottomView];

    

    CAGradientLayer *gradinetLayer = [CAGradientLayer layer];

    [bottomView.layer addSublayer:gradinetLayer];

    gradinetLayer.frame = CGRectMake(0, 10, bottomView.width, 30);

    gradinetLayer.startPoint = CGPointMake(0, 0.5);//要确定startPoint

    gradinetLayer.endPoint = CGPointMake(1, 0.5);//确定endPoint，这二者共同决定动画滚动的方向

    gradinetLayer.colors = @[

                             (__bridge id)[UIColor blackColor].CGColor,

                             (__bridge id)[UIColor whiteColor].CGColor,

                             (__bridge id)[UIColor blackColor].CGColor

                             ];

    gradinetLayer.locations = @[@0.25,@0.5,@0.75];

    // 添加部分

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

    basicAnimation.fromValue = @[@0, @0, @0.25];

    basicAnimation.toValue = @[@0.75, @1, @1];

    basicAnimation.duration = 2.0;

    basicAnimation.repeatCount = HUGE;

    [gradinetLayer addAnimation:basicAnimation forKey:nil];