UILabel颜色逐渐变化

@interface UIViewController ()

@property (weak, nonatomic) IBOutlet UIView *backView; //空间是用storyBoard创建的

@property (nonatomic, strong) CAGradientLayer* gradientLayer; 

 @end

 

@implementation UIViewController

- (void)viewDidLoad {

　　//设置Label的背景颜色渐变 要把label添加到一个View上

　　　

　　UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(0, 0, self.backView.frame.size.width, self.backView.frame.size.height)];

      label.textAlignment = NSTextAlignmentCenter;

      label.backgroundColor = [UIColor clearColor];

      label.text = @"label背景颜色渐变";

      label.font = [UIFont systemFontOfSize:17];

      label.textColor = [UIColor greenColor];

      [self.backView addSubview:label];

　　[self textGradientview:label1 bgVIew:self.backView gradientColors:@[(id)[self randomColor].CGColor, (id)[self randomColor].CGColor, (id)[self randomColor].CGColor]  gradientStartPoint:CGPointMake(0, 1) endPoint:CGPointMake(1, 0)];

 

　　//设置label文字的颜色渐变 重新创建一个View 

　 　

　　UILabel *label1 = [[UILabel alloc]initWithFrame:CGRectMake(60, 300, 300, 80)];

      label1.textAlignment = NSTextAlignmentCenter;

      label1.text = @"label字体的颜色渐变allalal";

      label1.font = [UIFont systemFontOfSize:20];

      label1.textColor = [UIColor greenColor];

      [self.view addSubview:label1];

      [self textGradientview:label1 bgVIew:self.view gradientColors:@[(id)[self randomColor].CGColor, (id)[self randomColor].CGColor, (id)[self randomColor].CGColor] gradientStartPoint:CGPointMake(0, 1) endPoint:CGPointMake(1, 1)];

      //

      NSTimer *timer = [NSTimer timerWithTimeInterval:.1 target:self selector:@selector(textColorChange) userInfo:nil repeats:YES];

      [[NSRunLoop mainRunLoop] addTimer:timer forMode:NSDefaultRunLoopMode];

}

/**

@param view Label

 @param bgVIew Label的父视图

 @param colors 颜色数组

 @param startPoint 开始的中心点

 @param endPoint 结束的中心点

 */

-(void)textGradientview:(UIView *)view bgVIew:(UIView *)bgVIew gradientColors:(NSArray *)colors gradientStartPoint:(CGPoint)startPoint endPoint:(CGPoint)endPoint {

    _gradientLayer = [CAGradientLayer layer];

    _gradientLayer.frame = view.frame;

    _gradientLayer.colors = colors;

    _gradientLayer.startPoint = startPoint;

    _gradientLayer.endPoint = endPoint;

    [bgVIew.layer addSublayer:_gradientLayer];

    _gradientLayer.mask = view.layer;

    view.frame = _gradientLayer.bounds;

}

-(UIColor *)randomColor{

    CGFloat r = arc4random_uniform(256) / 255.0;

    CGFloat g = arc4random_uniform(256) / 255.0;

    CGFloat b = arc4random_uniform(256) / 255.0;

    return [UIColor colorWithRed:r green:g blue:b alpha:1];

} 

// 定时器触发方法

-(void)textColorChange {

    _gradientLayer.colors = @[(id)[self randomColor].CGColor,

                              (id)[self randomColor].CGColor,

                              (id)[self randomColor].CGColor];

}

@end