ios - 如何在 iOS 的 UIView 上应用模糊效果？

Question

在我的应用程序中，我想在 uiview 上应用模糊效果。那么如何实现模糊效果。我尝试了以下代码:

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];

但使用此代码时遇到问题。当应用模糊效果时 View 变小。

Answer 1

只需将此模糊 View 放在您想要模糊的 View (这里是您的BlurredView)上。这是 Objective-C 中的示例:

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

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

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

和 swift :

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

visualEffectView.frame = yourBlurredView.bounds

yourBlurredView.addSubview(visualEffectView)