iOS 模糊效果的实现

有些时候,我们需要一些特殊的视觉效果,实现图片的模糊展示,实现代码如下:

- (void)viewDidLoad {    [super viewDidLoad];    UIImage * image = [UIImage imageNamed:@"leftbackiamge"];    CIImage * ciImage = [[CIImage alloc]initWithImage:image];    CIFilter * blurFilter = [CIFilter filterWithName:@"CIGaussianBlur"];    [blurFilter setValue:ciImage forKey:kCIInputImageKey];    CIImage * outImage = [blurFilter valueForKey:kCIOutputImageKey];    CIContext * context = [CIContext contextWithOptions:nil];    CGImageRef outCGImage = [context createCGImage:outImage fromRect:[outImage extent]];    UIImage * blurImage = [UIImage imageWithCGImage:outCGImage];    CGImageRelease(outCGImage);    UIImageView * imageView = [[UIImageView alloc]initWithFrame:self.view.bounds];    imageView.image = blurImage;    [self.view addSubview:imageView];}

效果图如下: