Question

Rean Wen在此post中提供的答案在Swift 2.2中运行得很好，但现在我使用Swift 3升级到XCode 8.0，它不再起作用了。

我收到以下错误消息：

.../project/AppDelegate.swift:41:108: Cannot convert value of type '(@convention(c) (CFNotificationCenter?, UnsafeMutableRawPointer?, CFString?, UnsafeRawPointer?, CFDictionary?) -> Void)!' to expected argument type 'CFNotificationCallback!'

从这一行：

CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), nil, LockNotifierCallback.notifierProc(), "com.apple.springboard.lockcomplete", nil, CFNotificationSuspensionBehavior.DeliverImmediately)

在AppDelegate.swift文件中。

有谁知道如何解决这个问题？自从我刚刚开始学习Swift以来，我们将非常感谢任何帮助。

Answer 1

这可能适合你。

CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(),
                                    nil,
                                    { (_, observer, name, _, _) in

                                        print("received notification: \(name)")
        },
                                    "com.apple.springboard.lockcomplete" as CFString!,
                                    nil,
                                    .deliverImmediately)

您可以查看answer以获取更多详细信息。

Answer 2

我最近在开发任务管理应用时遇到了同样的问题。我尝试使用带有CFNotificationCallback方法的Darwin Notification来解决这个问题。

步骤1：

在AppDelegate类声明

下添加以下代码

class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    let displayStatusChanged: CFNotificationCallback = { center, observer, name, object, info in
        let str = name!.rawValue as CFString
        if (str == "com.apple.springboard.lockcomplete" as CFString) {
            let isDisplayStatusLocked = UserDefaults.standard
            isDisplayStatusLocked.set(true, forKey: "isDisplayStatusLocked")
            isDisplayStatusLocked.synchronize()
        }
    }

    //other functions
}

第2步：

在didFinishLaunchingWithOptions内，添加以下代码：

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions:
[UIApplicationLaunchOptionsKey: Any]?) -> Bool {

    let isDisplayStatusLocked = UserDefaults.standard
    isDisplayStatusLocked.set(false, forKey: "isDisplayStatusLocked")
    isDisplayStatusLocked.synchronize()

    // Darwin Notification
    let cfstr = "com.apple.springboard.lockcomplete" as CFString
    let notificationCenter = CFNotificationCenterGetDarwinNotifyCenter()
    let function = displayStatusChanged
    CFNotificationCenterAddObserver(notificationCenter,
                                    nil,
                                    function,
                                    cfstr,
                                    nil,
                                    .deliverImmediately)

    return true
}

第3步：

在applicationDidEnterBackground内，添加以下代码：

func applicationDidEnterBackground(_ application: UIApplication) {      
    let isDisplayStatusLocked = UserDefaults.standard
    if let lock = isDisplayStatusLocked.value(forKey: "isDisplayStatusLocked"){
        // user locked screen
        if(lock as! Bool){            
            // do anything you want here
            print("Lock button pressed.")
        }
        // user pressed home button
        else{            
            // do anything you want here
            print("Home button pressed.")
        }
    }
}

第4步：

在applicationWillEnterForeground内，添加以下代码：

func applicationWillEnterForeground(_ application: UIApplication) {
    print("Back to foreground.")
    //restore lock screen setting
    let isDisplayStatusLocked = UserDefaults.standard
    isDisplayStatusLocked.set(false, forKey: "isDisplayStatusLocked")
    isDisplayStatusLocked.synchronize()  
}

您可以通过演示项目查看详细方法：swift-home-vs-lock-button

在Swift 3中检测iOS9和iOS10上的屏幕锁定或主页按钮

2 个答案: