Question

我正在尝试根据通话状态更改按钮状态。我使用此处的代码来检测呼叫状态：How to get a call event using CTCallCenter:setCallEventHandler: that occurred while the app was suspended?

当app在前台时，它可以正常工作。但它根本不适用于后台。在CTCallCenter.callEventHandler的文档中：

当您的应用程序恢复活动状态时，它会收到一个每次调用改变状态的调用事件 - 无论状态多少更改应用程序暂停时遇到的呼叫。该根据您的申请，将单个呼叫事件发送给您的处理程序返回活动状态，描述呼叫的状态时间。

但是，当应用恢复活动时，我没有收到任何通话事件。当应用程序处于前台时，我得到的是上次保存的呼叫状态。如何在后台检测呼叫状态？

这是我的代码：

AppDelegate.swift

  let callСenter = CTCallCenter()

    func block (call:CTCall!)
    {
        callState = String(call.callState)
        print(call.callState)
    }

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool
    {
        //check for call state
        callСenter.callEventHandler = block

...

        return true
    }

ViewController.swift

 override func viewDidLoad()
    {
        super.viewDidLoad()

        NotificationCenter.default.addObserver(
            self,
            selector: #selector(cameBackFromSleep),
            name: NSNotification.Name.UIApplicationDidBecomeActive,
            object: nil
        )

        ...
    }

    func cameBackFromSleep()
    {
        self.viewWillAppear(true)
    }

    override func viewWillAppear(_ animated: Bool)
    {
        switch callState
        {
        case "CTCallStateConnected":
            print("callState: ", callState)
            self.textLabel.isHidden = true
            startBtnAnimation()
        case "CTCallStateDisconnected":
            print("callState: ", callState)
            self.textLabel.center.y += self.view.bounds.height
            self.textLabel.isHidden = false
            stopBtnAnimation()
        default: break
        }
    }

Answer 1

最后，我解决了！我使用了这个答案中的代码：Find if user is in a call or not?

我从AppDelegate删除了所有内容，所有工作都在ViewController中完成：

override func viewDidLoad()
    {
        super.viewDidLoad()

        NotificationCenter.default.addObserver(
            self,
            selector: #selector(cameBackFromSleep),
            name: NSNotification.Name.UIApplicationDidBecomeActive,
            object: nil
        )

...

    }

    private func isOnPhoneCall() -> Bool
    {
        let callCntr = CTCallCenter()

        if let calls = callCntr.currentCalls
        {
            for call in calls
            {
                if call.callState == CTCallStateConnected || call.callState == CTCallStateDialing || call.callState == CTCallStateIncoming
                {
                    print("In call")
                    return true
                }
            }
        }

        print("No calls")
        return false
    }

    func cameBackFromSleep()
    {

        self.viewWillAppear(true)
    }

    override func viewWillAppear(_ animated: Bool)
    {
        print("is on call", isOnPhoneCall())
        switch isOnPhoneCall()
        {
        case true:
            print("startBtnAnimation")
            startBtnAnimation()
            recordBtnIsPressed = true
        case false:
            print("stopBtnAnimation")
            stopBtnAnimation()
            recordBtnIsPressed = false
        default: break
        }
    }

现在它运作正常。不确定为什么CTCallCenter在AppDelegate中工作得如此奇怪。

iOS如何在后台检测呼叫状态？

1 个答案: