嗨,在这里,我正在使用下面的代码检查设备的屏幕是打开还是关闭。我从this SO post获得此代码。

码:

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        // Override point for customization after application launch.

        CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), nil, displayStatusChanged, "com.apple.springboard.lockcomplete", nil, CFNotificationSuspensionBehavior.deliverImmediately)
        //CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), nil, displayStatusChanged, "com.apple.springboard.lockstate", nil, CFNotificationSuspensionBehavior.deliverImmediately)

        return true
    }
}//AppDelegate class end here

func displayStatusChanged(center:CFNotificationCenter,observer: UnsafeMutableRawPointer?,name:CFString,object: UnsafeRawPointer?,userInfo:CFDictionary) -> Void {

}


但是我得到了这个错误:


  无法转换类型为'(CFNotificationCenter,
  UnsafeMutableRawPointer?,CFString,UnsafeRawPointer?,CFDictionary)
  ->无效”到期望的参数类型“ CFNotificationCallback!” (又名'ImplicitlyUnwrappedOptional   (可选,可选,
  可选,可选,
  可选)->()>')


有人知道displayStatusChanged函数在做什么吗?任何帮助,建议或链接将不胜感激。

谢谢

最佳答案

根据the documentation


center参数应该是可选的(即缺少?),
对于name,您具有CFString,但文档中显示CFNotificationName?
并且CFDictionary应该是可选的(您错过了?),


如果您将参数与期望的类型匹配,则应该修复您的错误。

func displayStatusChanged(center: CFNotificationCenter?, observer: UnsafeMutableRawPointer?, name: CFNotificationName?, object: UnsafeRawPointer?, userInfo: CFDictionary?) -> Void {

}

关于ios - 在iOS中检查设备屏幕打开或关闭,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/50969923/

10-12 14:50