我想显示一个透明的 subview ，因此模糊了主视图 Controller 。这工作正常，但是当返回到主视图 Controller 时，模糊仍然存在 - 并且它不会进入主视图中的任何部分，例如 View 确实出现或 popoverPresentationControllerDidDismissPopover。

我运行这段代码来创建模糊并显示 subview :

if !UIAccessibilityIsReduceTransparencyEnabled() {
    self.view.backgroundColor = UIColor.clear

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

    self.view.addSubview(blurEffectView)
}

let popOverVC = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "PriceAlarmPopUp") as!  PriceAlarmPopupViewController
self.addChildViewController(popOverVC)
popOverVC.view.frame = self.view.frame
self.view.addSubview(popOverVC.view)

popOverVC.didMove(toParentViewController: self)

完成 subview 时，我会:

self.view.removeFromSuperview()

我做错了什么吗？我已经尝试了几种解决方案，但无法摆脱模糊 subview 。

最佳答案

为您的模糊 View 保留弱引用，然后将其从父 View 中移除:

class MyVC: UIViewController {

    private weak var blurView: UIView?

    func foo() {
        if !UIAccessibilityIsReduceTransparencyEnabled() {
            self.view.backgroundColor = UIColor.clear
            let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.extraLight)
            let blurEffectView = UIVisualEffectView(effect: blurEffect)
            blurEffectView.frame = self.view.bounds
            blurEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
            self.view.addSubview(blurEffectView)
            blurView = blurEffectView // HERE YOU SAVE WEAK REFERENCE
        }

        let popOverVC = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "PriceAlarmPopUp") as!  PriceAlarmPopupViewController
        self.addChildViewController(popOverVC)
        popOverVC.view.frame = self.view.frame
        self.view.addSubview(popOverVC.view)

        popOverVC.didMove(toParentViewController: self)
    }

    func fooDone() {
        blurView?.removeFromSuperview() // Blur view will be removed from sureview and automatically `blurView` becomes to `nil`
    }
}

如果你想对另一个 View Controller 隐藏它，使用闭包:

class MyVC: UIViewController {
    func foo() {
        let popOverVC = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "PriceAlarmPopUp") as!  PriceAlarmPopupViewController
        self.addChildViewController(popOverVC)
        popOverVC.view.frame = self.view.frame
        if !UIAccessibilityIsReduceTransparencyEnabled() {
            self.view.backgroundColor = UIColor.clear
            let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.extraLight)
            let blurEffectView = UIVisualEffectView(effect: blurEffect)
            blurEffectView.frame = self.view.bounds
            blurEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
            self.view.addSubview(blurEffectView)
            popOverVC.userTappedCloseButtonClosure = { [weak blurEffectView] in
                blurEffectView?.removeFromSuperview()
            }
        }
        self.view.addSubview(popOverVC.view)
        popOverVC.didMove(toParentViewController: self)
    }
}

class PriceAlarmPopupViewController: UIViewController {
    public var userTappedCloseButtonClosure: (() -> Void)?

    @IBAction func closeButtonAction(_ sender: Any) {
        userTappedCloseButtonClosure?()
    }
}

关于ios - 返回主视图时不会消除快速模糊效果，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/45085332/