如何在 iOS 中判断暗模式

UIKit拥有UITraitCollection已经有一段时间了.从iOS 9开始，你可以使用UITraitCollection来查看该设备是否支持3D Touch(另一天的悲伤对话)

In iOS 12，UITraitCollection获得了一个新属性:var userInterfaceStyle: UIUserInterfaceStyle，它支持三种情况:light、dark和unspecified

由于UIViewController继承了UITraitenEnvironment，因此您可以访问ViewController的traitCollection.这是userInterfaceStylestore .

UITraitEnviroment还有一些漂亮的协议存根，可以帮助代码在状态发生变化时进行解释(因此当用户从黑暗面切换到Illuminate 面或反之亦然).下面是一个很好的编码示例:

class MyViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        if self.traitCollection.userInterfaceStyle == .dark {
            // User Interface is Dark
        } else {
            // User Interface is Light
        }

    }


    override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
        // Trait collection has already changed
    }

    override func willTransition(to newCollection: UITraitCollection, with coordinator: UIViewControllerTransitionCoordinator) {
        // Trait collection will change. Use this one so you know what the state is changing to.
    }
}