无法设置UIScreen.main.brightness = 1.0

Question

我把UIScreen.main.brightness = 1.0设为viewDidLoad。

但UIScreen.main.brightness控制台中的打印值为0.9483038187026978。

请帮帮我。我英语不好，很抱歉

Answer 1

您可以使用SceneDelegate，如下文所述：

https://medium.com/@arikisintown/how-to-create-an-ios-app-that-takes-secret-photos-while-the-iphone-screen-seems-to-be-turned-off-7081d110309e

--

从该条中：

我们将添加一个单独的类，专门用于控制屏幕亮度：

final class DimUnDim {
    static let shared = DimUnDim()
    private var originalBrightness = UIScreen.main.brightness
    func dim() {
        print("dim")
        UIScreen.main.wantsSoftwareDimming = true
        UIScreen.main.brightness = 0.0
    }
    func unDim() {
        print("unDim")
        UIScreen.main.brightness = originalBrightness
    }
}

当应用程序变得活跃时，我们将调用Dim，当应用程序不活动时，我们将调用UnDim。编辑文件SceneDelegate.swift并添加以下内容：

func sceneDidBecomeActive(_ scene: UIScene) {
    DimUnDim.shared.dim()
}
func sceneWillResignActive(_ scene: UIScene) {     
    DimUnDim.shared.unDim()
}