Ios 在swift中为背景添加模糊效果

我正在设置背景图像以查看控制器。但我也想给这个背景添加模糊效果。我该怎么做

我正在使用以下代码设置背景：

self.view.backgroundColor = UIColor(patternImage: UIImage(named: "testBg")!)

我在互联网上找到了blur imageview，如何在我的背景中实现这一点

var darkBlur = UIBlurEffect(style: UIBlurEffectStyle.Dark)
// 2
var blurView = UIVisualEffectView(effect: darkBlur)
blurView.frame = imageView.bounds
// 3
imageView.addSubview(blurView)

---

我已经测试了此代码，它运行良好：

let blurEffect = UIBlurEffect(style: UIBlurEffect.Style.dark)
let blurEffectView = UIVisualEffectView(effect: blurEffect)
blurEffectView.frame = view.bounds
blurEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
view.addSubview(blurEffectView)

对于Swift 3.0：

let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.dark)
let blurEffectView = UIVisualEffectView(effect: blurEffect)
blurEffectView.frame = view.bounds
blurEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
view.addSubview(blurEffectView)

对于Swift 4.0：

let blurEffect = UIBlurEffect(style: UIBlurEffect.Style.dark)
let blurEffectView = UIVisualEffectView(effect: blurEffect)
blurEffectView.frame = view.bounds
blurEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
view.addSubview(blurEffectView)

在这里您可以看到结果：

或者，您可以使用此库：

---

您可以对UIImageView进行扩展

Swift 2.0

import Foundation
import UIKit

extension UIImageView
{
    func makeBlurImage(targetImageView:UIImageView?)
    {
        let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.Dark)
        let blurEffectView = UIVisualEffectView(effect: blurEffect)
        blurEffectView.frame = targetImageView!.bounds

        blurEffectView.autoresizingMask = [.FlexibleWidth, .FlexibleHeight] // for supporting device rotation
        targetImageView?.addSubview(blurEffectView)
    }
}

var darkBlur:UIBlurEffect = UIBlurEffect()

if #available(iOS 10.0, *) { //iOS 10.0 and above
    darkBlur = UIBlurEffect(style: UIBlurEffectStyle.prominent)//prominent,regular,extraLight, light, dark
} else { //iOS 8.0 and above
  darkBlur = UIBlurEffect(style: UIBlurEffectStyle.dark) //extraLight, light, dark
}
let blurView = UIVisualEffectView(effect: darkBlur)
blurView.frame = self.view.frame //your view that have any objects
blurView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
view.addSubview(blurView)

用法：

override func viewDidLoad()
{
    super.viewDidLoad()

    let sampleImageView = UIImageView(frame: CGRectMake(0, 200, 300, 325))
    let sampleImage:UIImage = UIImage(named: "ic_120x120")!
    sampleImageView.image =  sampleImage

    //Convert To Blur Image Here
    sampleImageView.makeBlurImage(sampleImageView)

    self.view.addSubview(sampleImageView)
}

yourImageView.addBlurEffect()

extension UIView {
  
  /// Remove UIBlurEffect from UIView
  func removeBlurEffect() {
    let blurredEffectViews = self.subviews.filter{$0 is UIVisualEffectView}
    blurredEffectViews.forEach{ blurView in
      blurView.removeFromSuperview()
    }
  }

Swift 3分机

import Foundation
import UIKit

extension UIImageView
{
    func addBlurEffect()
    {
        let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.light)
        let blurEffectView = UIVisualEffectView(effect: blurEffect)
        blurEffectView.frame = self.bounds

        blurEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight] // for supporting device rotation
        self.addSubview(blurEffectView)
    }
}

用法：

override func viewDidLoad()
{
    super.viewDidLoad()

    let sampleImageView = UIImageView(frame: CGRectMake(0, 200, 300, 325))
    let sampleImage:UIImage = UIImage(named: "ic_120x120")!
    sampleImageView.image =  sampleImage

    //Convert To Blur Image Here
    sampleImageView.makeBlurImage(sampleImageView)

    self.view.addSubview(sampleImageView)
}

yourImageView.addBlurEffect()

extension UIView {
  
  /// Remove UIBlurEffect from UIView
  func removeBlurEffect() {
    let blurredEffectViews = self.subviews.filter{$0 is UIVisualEffectView}
    blurredEffectViews.forEach{ blurView in
      blurView.removeFromSuperview()
    }
  }

附录：

override func viewDidLoad()
{
    super.viewDidLoad()

    let sampleImageView = UIImageView(frame: CGRectMake(0, 200, 300, 325))
    let sampleImage:UIImage = UIImage(named: "ic_120x120")!
    sampleImageView.image =  sampleImage

    //Convert To Blur Image Here
    sampleImageView.makeBlurImage(sampleImageView)

    self.view.addSubview(sampleImageView)
}

yourImageView.addBlurEffect()

extension UIView {
  
  /// Remove UIBlurEffect from UIView
  func removeBlurEffect() {
    let blurredEffectViews = self.subviews.filter{$0 is UIVisualEffectView}
    blurredEffectViews.forEach{ blurView in
      blurView.removeFromSuperview()
    }
  }

Swift 5.0：

import UIKit


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

---

@AlvinGeorge只需使用：

extension UIImageView{        
    func blurImage()
    {
        let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.Dark)
        let blurEffectView = UIVisualEffectView(effect: blurEffect)
        blurEffectView.frame = self.bounds

        blurEffectView.autoresizingMask = [.FlexibleWidth, .FlexibleHeight] // for supporting device rotation
        self.addSubview(blurEffectView)
    }
}

用法：

 blurredBackground.frame = self.view.bounds
 blurredBackground.blurImage()
 self.view.addSubview(self.blurredBackground)

---

U还可以使用CoreImage创建具有暗效果的模糊图像

为图像创建快照

func snapShotImage() -> UIImage {
    UIGraphicsBeginImageContext(self.frame.size)
    if let context = UIGraphicsGetCurrentContext() {
        self.layer.renderInContext(context)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image
    }

    return UIImage()
}

应用CoreImage过滤器，如您所愿

private func bluredImage(view:UIView, radius:CGFloat = 1) -> UIImage {
let image = view.snapShotImage()

if let source = image.CGImage {
    let context = CIContext(options: nil)
    let inputImage = CIImage(CGImage: source)

    let clampFilter = CIFilter(name: "CIAffineClamp")
    clampFilter?.setDefaults()
    clampFilter?.setValue(inputImage, forKey: kCIInputImageKey)

    if let clampedImage = clampFilter?.valueForKey(kCIOutputImageKey) as? CIImage {
        let explosureFilter = CIFilter(name: "CIExposureAdjust")
        explosureFilter?.setValue(clampedImage, forKey: kCIInputImageKey)
        explosureFilter?.setValue(-1.0, forKey: kCIInputEVKey)

        if let explosureImage = explosureFilter?.valueForKey(kCIOutputImageKey) as? CIImage {
            let filter = CIFilter(name: "CIGaussianBlur")
            filter?.setValue(explosureImage, forKey: kCIInputImageKey)
            filter?.setValue("\(radius)", forKey:kCIInputRadiusKey)

            if let result = filter?.valueForKey(kCIOutputImageKey) as? CIImage {
                let bounds = UIScreen.mainScreen().bounds
                let cgImage = context.createCGImage(result, fromRect: bounds)
                let returnImage = UIImage(CGImage: cgImage)
                return returnImage
            }
        }
    }
}
return UIImage()
}

---

找到了另一种方法。。我使用苹果的UIImage+ImageEffects

 UIImage *effectImage = [image applyExtraLightEffect];                        
 self.imageView.image = effectImage;

适用于Swift 3（iOS 10.0和8.0）

---

这个始终保持正确的框架：

public extension UIView {

    @discardableResult
    public func addBlur(style: UIBlurEffect.Style = .extraLight) -> UIVisualEffectView {
        let blurEffect = UIBlurEffect(style: style)
        let blurBackground = UIVisualEffectView(effect: blurEffect)
        addSubview(blurBackground)
        blurBackground.translatesAutoresizingMaskIntoConstraints = false
        blurBackground.bottomAnchor.constraint(equalTo: bottomAnchor).isActive = true
        blurBackground.topAnchor.constraint(equalTo: topAnchor).isActive = true
        blurBackground.leadingAnchor.constraint(equalTo: leadingAnchor).isActive = true
        blurBackground.trailingAnchor.constraint(equalTo: trailingAnchor).isActive = true
        return blurBackground
    }
}

---

这个代码对我来说很好用！ 它适用于Swift 4.x

let blurEffect = UIBlurEffect(style: .ExtraLight)
let blurEffectView = UIVisualEffectView(effect: blurEffect)
blurEffectView.frame = self.view.frame
self.view.insertSubview(blurEffectView, atIndex: 0)

---

这对我在Swift 5上起了作用

let blurredView = UIVisualEffectView(effect: UIBlurEffect(style: .light))
blurredView.frame = self.view.bounds
backgroundimage.addSubview(blurredView)

---

您应该始终使用.dark作为样式，并添加以下代码使其看起来很酷

    blurEffectView.backgroundColor = .black
    blurEffectView.alpha = 0.4

在UIView扩展中：

func addBlurredBackground(style: UIBlurEffect.Style) {
    let blurEffect = UIBlurEffect(style: style)
    let blurView = UIVisualEffectView(effect: blurEffect)
    blurView.frame = self.frame
    blurView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
    self.addSubview(blurView)
    self.sendSubviewToBack(blurView)
}

---

有没有办法改变模糊比例？它太模糊了。只需更改

UIBlurEffectStyle.Light

，或者可以将UIVisualEffectView上的alpha设置为小于1.0。尝试0.8或0.7。苹果不建议更改visualEffectVİ的alpha。所有控件都隐藏在此模糊下。而是添加子视图-使用self.view.insertSubview（blurEffectView，at:0）好主意！难道不能只是makeBlurImage（）然后使用self而不是targetImageView吗？我不确定，但是如果没有正确传递参数，这段代码可能会崩溃？这应该有一个“如果让tmpTargetImageView=targetImageView{}”statement@RomOne如果不提供参数，只会出现编译错误/生成失败。而且，它可以在没有图像的情况下工作，因此无需打开图像；测试将显示您是否忘记添加图像。关键是，如果传递了nil ImageView，它将崩溃。@EmanueleFumagalli的理想想法是使用self而不是targetImageView，但也可以使用guard语句，并在参数为nil的情况下返回。最好也使用模糊描述图像。好的，谢谢。请看这里的自定义模糊比例Hi@Marta，你知道如何减少blurredView的容量吗？