我们在做界面布局的时候，毛玻璃效果也时常的应用在我们的应用当中，利用播放视频的时候，视频没有加载出来，需要放一张毛玻璃图片来显示

// 定义毛玻璃效果
    UIBlurEffect * blur = [UIBlurEffect effectWithStyle:UIBlurEffectStyleDark];
    UIVisualEffectView * effe = [[UIVisualEffectView alloc]initWithEffect:blur];
    effe.frame = CGRectMake(50, 90, self.view.frame.size.width - 100, 400);
    // 把要添加的视图加到毛玻璃上
    UIButton * but = [[UIButton alloc]initWithFrame:CGRectMake(50, 50, 100, 100)];
    but.backgroundColor = [UIColor redColor];
    [effe addSubview:but];
    [self.view addSubview:effe];
//他的效果是枚举，有三种
UIBlurEffectStyleExtraLight
UIBlurEffectStyleLight
UIBlurEffectStyleDark

// 定义需要毛玻璃化的图片
    UIImageView * image = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"2.png"]];
    image.frame = CGRectMake(100, 100, 100, 100);

图片模糊:
    // 定义毛玻璃效果
    UIBlurEffect * blur = [UIBlurEffect effectWithStyle:UIBlurEffectStyleDark];
    UIVisualEffectView * effe = [[UIVisualEffectView alloc]initWithEffect:blur];
    effe.frame = CGRectMake(50, 90, self.view.frame.size.width - 100, 400);
    // 添加毛玻璃
    [image addSubview:effe];
    [self.view addSubview:image];