先看一下简单的使用

// 创建一个特效对象
UIBlurEffect *blurEffect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleLight];

// 创建一个毛玻璃视图
UIVisualEffectView *blurView = [[UIVisualEffectView alloc] initWithEffect:blurEffect];
blurView.clipsToBounds = YES;
blurView.layer.borderColor = [[UIColor blackColor] colorWithAlphaComponent:0.4f].CGColor;
blurView.layer.borderWidth = 1.0;
blurView.layer.cornerRadius = 6.0;

// label
UILabel *label = [[UILabel alloc] init];
label.textColor = [UIColor colorWithWhite:0.4f alpha:1.0f];

// add the label to effect view
[blurView.contentView addSubview:label];