iOS实现毛玻璃效果

– (UIImage *)blur:(UIImage *)theImage

{

    CIContext *context = [CIContextcontextWithOptions:nil];

    CIImage *inputImage = [CIImageimageWithCGImage:theImage.CGImage];

    CIFilter *filter = [CIFilterfilterWithName:@"CIGaussianBlur"];

    [filter setValue:inputImageforKey:kCIInputImageKey];

    [filter setValue:[NSNumbernumberWithFloat:15.0]forKey:@"inputRadius"];//其中数值是模糊度（3～30，越大越模糊）

    CIImage *result = [filtervalueForKey:kCIOutputImageKey];

    CGImageRef cgImage = [contextcreateCGImage:resultfromRect:[inputImageextent]];

    UIImage *returnImage = [UIImageimageWithCGImage:cgImage];

    CGImageRelease(cgImage);

    return returnImage;

    if (!UIAccessibilityIsReduceTransparencyEnabled()) {

        UIBlurEffect *blurEffect = [UIBlurEffecteffectWithStyle:UIBlurEffectStyleDark];

        UIVisualEffectView *blurEffectView = [[UIVisualEffectViewalloc]initWithEffect:blurEffect];

        blurEffectView.frame = _imageView.bounds;

        [_imageView addSubview:blurEffectView];