如何模糊效果适用于iOS中的UIView？

Question

在我的应用程序中,我想在uiview上应用模糊效果.所以我怎样才能实现模糊效果.我试过下面的代码:

UIGraphicsBeginImageContext(scrollview.bounds.size);
[scrollview.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

//Blur the UIImage with a CIFilter
CIImage *imageToBlur = [CIImage imageWithCGImage:viewImage.CGImage];
CIFilter *gaussianBlurFilter = [CIFilter filterWithName: @"CIGaussianBlur"];
[gaussianBlurFilter setValue:imageToBlur forKey: @"inputImage"];
[gaussianBlurFilter setValue:[NSNumber numberWithFloat:3] forKey: @"inputRadius"];
CIImage *resultImage = [gaussianBlurFilter valueForKey: @"outputImage"];
UIImage *endImage = [[UIImage alloc] initWithCIImage:resultImage];

//Place the UIImage in a UIImageView
UIImageView *newView = [[UIImageView alloc] initWithFrame:scrollview.bounds];
newView.image = endImage;
[scrollview addSubview:newView];

但是使用此代码时遇到问题.当应用模糊效果时,时间视图变小.

Answer 1

只需将此模糊视图放在您想要模糊的View(此处为yourBlurredView)上即可.这是Objective-C中的一个例子:

UIVisualEffect *blurEffect; 
blurEffect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleLight];

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

visualEffectView.frame = yourBlurredView.bounds; 
[yourBlurredView addSubview:visualEffectView];

和斯威夫特:

var visualEffectView = UIVisualEffectView(effect: UIBlurEffect(style: .light))    

visualEffectView.frame = yourBlurredView.bounds

yourBlurredView.addSubview(visualEffectView)

Answer 2

斯威夫特 5 扩展！

extension UIView {
    func applyBlurEffect(_ style: UIBlurEffect.Style = .light) {
        let blurEffect = UIBlurEffect(style: style)
        let blurEffectView = UIVisualEffectView(effect: blurEffect)
        blurEffectView.frame = bounds
        blurEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        addSubview(blurEffectView)
    }
}

像这样在 UIView 的任何子类上使用它

view.applyBlurEffect(.light)

Answer 3

如果您使用的是 iOS 8 或更高版本，请尝试使用UIVisualEffectView带有UIBlurEffect.