iOS 8使用UIBlurEffect实现毛玻璃特效

iOS 8 后使用UIBlurEffect 类和UIVisualEffectView 类添加毛玻璃特效更加便捷，高效。

//创建ImageView
IImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"5"]];
  // 创建需要的毛玻璃特效类型
  /**
   * UIBlurEffectStyleExtraLight,
   * UIBlurEffectStyleLight,
   * UIBlurEffectStyleDark
   */
  UIBlurEffect *blur = [UIBlurEffect effectWithStyle:UIBlurEffectStyleExtraLight];

  //添加到要有毛玻璃特效的控件中
  UIVisualEffectView *visual = [[UIVisualEffectView alloc] initWithEffect:blur];
  visual.frame = imageView.bounds;
  [self.view addSubview:imageView];