iOS 支持毛玻璃效果修改模糊度

有时候，设计要求的毛玻璃模糊程度，系统的视图无法满足我们的需求，就需要使用UIViewPropertyAnimator 来实现了，代码如下

复制代码

//
// LBVisualEffectView.swift
//  
//
//

import SnapKit
import Foundation

class LBViewPropertyAnimator: UIViewPropertyAnimator {}

public class LBVisualEffectView: UIView {
    private var animator: LBViewPropertyAnimator?
    private var effectView = UIVisualEffectView()

    private var visualEffect: UIVisualEffect? {
        didSet {
            animator?.stopAnimation(true)
            effectView.effect = visualEffect
            buildBlurFraction(effectFraction)
        }
    }

    private var effectFraction: CGFloat?

    private var visualEffectToken: LBThemeToken.VisualEffect? {
        didSet {
            visualEffect = visualEffectToken?.literaryContent
        }
    }

    deinit {
        animator?.stopAnimation(true)
    }

    override public init(frame: CGRect) {
        super.init(frame: frame)
        render()
        makeObservation()
    }

    @available(*, unavailable)
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    private func render() {
        addSubview(effectView)
        effectView.snp.remakeConstraints { make in
            make.edges.equalToSuperview()
        }
    }

    private func makeObservation() {
        NotificationCenter
            .default
            .addObserver(
                forName: UIApplication.willEnterForegroundNotification,
                object: nil,
                queue: .main
            ) { [weak self] _ in
                guard let self else {
                    return
                }
                animator?.stopAnimation(true)
                buildBlurFraction(effectFraction)
            }

        LBTheme.addThemeObserver(self)
    }

    public override func didMoveToWindow() {
        super.didMoveToWindow()
        buildBlurFraction(effectFraction)
    }

    @discardableResult
    public func buildVisualEffect(visualEffect: LBThemeToken.VisualEffect) -> Self {
        visualEffectToken = visualEffect
        return self
    }

    @discardableResult
    public func buildVisualEffect(style: UIBlurEffect.Style) -> Self {
        visualEffect = UIBlurEffect(style: style)
        return self
    }

    @discardableResult
    public func buildVisualEffect(blurStyle: UIBlurEffect.Style, vibrancyStyle: UIVibrancyEffectStyle) -> Self {
        visualEffect = UIVibrancyEffect(blurEffect: UIBlurEffect(style: blurStyle), style: vibrancyStyle)
        return self
    }

    @discardableResult
    public func buildBlurFraction(_ fraction: CGFloat?) -> Self {
        effectFraction = fraction
        guard let fraction, fraction >= 0, fraction <= 1 else {
            animator?.stopAnimation(true)
            return self
        }
        effectView.effect = nil
        animator?.stopAnimation(true)
        animator = nil
        animator = LBViewPropertyAnimator(duration: 0.5, curve: .linear)
        animator?.addAnimations { [weak self] in
            guard let self else {
                return
            }
            //[UIBlurEffect effectWithStyle:UIBlurEffectStyleExtraLight]
            effectView.effect = UIBlurEffect(style: .light)
        }
//        animator?.addCompletion { [weak self] _ in
//            guard let self else {
//                return
//            }
//            if let window {
//                buildBlurFraction(fraction)
//            }
//        }
//        animator?.startAnimation()
//        animator?.pauseAnimation()
        animator?.fractionComplete = fraction
        return self
    }
}

extension LBVisualEffectView: LBThemeableCustomItem {
    public func themeDidChange() {
        visualEffect = visualEffectToken?.literaryContent
    }
}

使用方法

复制代码

 private let blurView = {
        let view = LBVisualEffectView()
        view.buildVisualEffect(
            visualEffect: .createVisualEffect(light: .createBlur(style: .light), dark: .createBlur(style: .light))).buildBlurFraction(0.4)
        return view
    }()