笔记效果图

Untitled.gif

创建UIView的Category

#import <UIKit/UIKit.h>

@interface UIView (FlashesMask)

/**
 开始

 @param count 循环次数
 @param duration 单次时间
 @param FlashesWidth 光圈宽度
 */
-(void)flashesMaskAimationBeginWithRepeatCount:(CGFloat)count duration:(NSTimeInterval)duration FlashesWidth:(CGFloat)FlashesWidth;

/**
 结束
 */
-(void)flashesMaskAimationStop;

@end

#import "UIView+FlashesMask.h"
#define FlashesMaskAinmation @"FlashesMaskAinmation"

@implementation UIView (FlashesMask)

-(void)flashesMaskAimationBeginWithRepeatCount:(CGFloat)count duration:(NSTimeInterval)duration FlashesWidth:(CGFloat)FlashesWidth
{
    NSAssert([self isKindOfClass:[UIView class]], @"必须是UIView子类");
    
    CAGradientLayer *FlashesMaskLayer = [[CAGradientLayer alloc]init];
    [FlashesMaskLayer setFrame:self.bounds];
    CGFloat flashSize = FlashesWidth / self.frame.size.width;
    
    NSArray *startLocations = @[@0,
                                [NSNumber numberWithFloat:(flashSize / 2.)],
                                [NSNumber numberWithFloat:flashSize]
                                ];
    NSArray *endLocations = @[[NSNumber numberWithFloat:(1. - flashSize)],
                              [NSNumber numberWithFloat:(1. - (flashSize / 2.))],
                              @1
                              ];
    FlashesMaskLayer.locations = startLocations;
    FlashesMaskLayer.startPoint = CGPointMake(0 - (flashSize * 2), .5);
    FlashesMaskLayer.endPoint = CGPointMake(1 + flashSize, .5);
    [FlashesMaskLayer setColors:@[(id)[UIColor colorWithWhite:1 alpha:1].CGColor,(id)[UIColor colorWithWhite:0 alpha:0.1].CGColor,(id)[UIColor colorWithWhite:1 alpha:1].CGColor]];
    CABasicAnimation * base = [CABasicAnimation animationWithKeyPath:@"locations"];
    base.fromValue = startLocations;
    base.toValue = endLocations;
    
    [base setDuration:duration];
    
    [base setRepeatCount:count];
    self.layer.mask=FlashesMaskLayer;
    [FlashesMaskLayer addAnimation:base forKey:FlashesMaskAinmation];
}
-(void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag
{
    if ([anim valueForKey:FlashesMaskAinmation]) {
        self.layer.mask = nil;
    }
}
-(void)flashesMaskAimationStop{
    [self.layer.mask removeAnimationForKey:FlashesMaskAinmation];
}

@end

使用

 UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(100, 100, 200, 50)];
    label.text = @"小的时候上学老师总是说你比不过我我也躲在角落里偷偷笑过";
    label.font = [UIFont boldSystemFontOfSize:18];
    label.textColor = [UIColor blueColor];
    [self.view addSubview:label];
    [label flashesMaskAimationBeginWithRepeatCount: HUGE_VALF duration:0.8 FlashesWidth:30];