UILabel 背景添加渐变，文字消失的处理方法

'''
/// 给view的背景添加渐变色

• (void)setViewBackColors:(UIColor *)startColor endColor:(UIColor *)endColor andLocations:(NSArray *)locations{
  //渐变颜色
  CAGradientLayer *gradientLayer = [CAGradientLayer layer];
  gradientLayer.colors = @[(__bridge id)startColor.CGColor, (__bridge id)endColor.CGColor];
  gradientLayer.locations = locations;
  gradientLayer.startPoint = CGPointMake(0, 0);
  gradientLayer.endPoint = CGPointMake(1.0, 1.0);
  gradientLayer.frame = self.bounds;
  gradientLayer.cornerRadius = self.layer.cornerRadius;
  [self.layer insertSublayer:gradientLayer atIndex:-1];
  }

'''

但是 对于UILabel设置背景完全没用啊，uibutton又不能改，终于知道了这个办法

‘’‘
UIColor *color = [UIColor colorWithPatternImage:[UIImage imageNamed:@"bg_norvip_price_frog"]];
[self setBackgroundColor:color];
’‘’