如何为自定义UITabBarController配置scrollEdgeAppearance并保持样式禁用透明

要解决滚动时TabBar变透明的问题，核心是统一配置standardAppearance和scrollEdgeAppearance，让两种状态下的样式保持一致，同时适配你自定义的CAShapeLayer效果：

修改你的configureTabbar方法，补充以下配置：

func configureTabbar() {
    // 1. 创建统一的TabBar外观配置实例
    let tabBarAppearance = UITabBarAppearance()
    // 将背景设为透明，避免覆盖自定义的CAShapeLayer
    tabBarAppearance.backgroundEffect = nil
    tabBarAppearance.backgroundColor = .clear
    
    // 配置选中状态的图标/文字颜色（与原有设置对齐）
    tabBarAppearance.stackedLayoutAppearance.selected.iconColor = AppColors.tabbarTintColor
    tabBarAppearance.stackedLayoutAppearance.selected.titleTextAttributes = [.foregroundColor: AppColors.tabbarTintColor]
    // 若有未选中状态的样式需求，补充以下配置
    // tabBarAppearance.stackedLayoutAppearance.normal.iconColor = 你的未选中图标颜色
    // tabBarAppearance.stackedLayoutAppearance.normal.titleTextAttributes = [.foregroundColor: 你的未选中文字颜色]
    
    // 2. 同时配置两种外观，确保滚动状态样式一致
    tabBar.standardAppearance = tabBarAppearance
    // iOS 15+ 需单独配置scrollEdgeAppearance，解决滚动到顶部时的透明问题
    if #available(iOS 15.0, *) {
        tabBar.scrollEdgeAppearance = tabBarAppearance
    }
    
    // --- 你原有的自定义TabBar代码保持不变 ---
    UITabBar.appearance().tintColor = AppColors.tabbarTintColor
    
    let cornerRadius: CGFloat = 15
    
    let layer = CAShapeLayer()
    layer.path = UIBezierPath(roundedRect: CGRect(x: 45, y: self.tabBar.bounds.minY - 10, width: self.tabBar.bounds.width - 90, height: self.tabBar.bounds.height + 10), cornerRadius: cornerRadius).cgPath
    layer.shadowColor = UIColor.lightGray.cgColor
    layer.shadowOffset = CGSize(width: 5.0, height: 5.0)
    layer.shadowRadius = 25.0
    layer.shadowOpacity = 0.3
    layer.borderWidth = 1.0
    layer.opacity = 1.0
    layer.isHidden = false
    layer.masksToBounds = false
    layer.fillColor = AppColors.tabbarBG.cgColor
    
    self.tabBar.layer.insertSublayer(layer, at: 0)
    
    if let items = self.tabBar.items {
        items.forEach { item in
            item.imageInsets = UIEdgeInsets(top: 0, left: 0, bottom: -15, right: 0)
        }
    }
    
    self.tabBar.itemWidth = 30.0
    self.tabBar.itemPositioning = .centered
}

关键说明： #

• 将外观的backgroundColor设为.clear，是为了让你手动添加的CAShapeLayer能正常显示，不会被系统默认的背景层覆盖
• 同时设置standardAppearance和scrollEdgeAppearance，确保滚动到顶部时TabBar的样式与普通状态完全一致
• 原代码中UITabBar.appearance().backgroundColor可移除，避免与新的外观配置产生冲突

内容的提问来源于stack exchange，提问作者Thush-Fdo