几行代码实现图片的模糊效果

// 创建一个imageView

UIImageView * backImageView = [[UIImageView alloc]initWithFrame:self.view.bounds];

backImageView.image = [UIImage imageNamed:@"guidance03@3x.jpg"];

[self.view addSubview:backImageView];

//添加模糊效果

UIBlurEffect * blurEffect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleLight];

UIVisualEffectView * effectView = [[UIVisualEffectView alloc]initWithEffect:blurEffect];

effectView.frame = CGRectMake(0, 64, self.view.frame.size.width, 300);

[backImageView addSubview:effectView];