Xamarin iOS get status back of a phone call

问题:

Is there a way to get the call status back after a call is made from an app. I am using following to make a call

  NSUrl url = new NSUrl("tel://" + phoneStr);
  UIApplication.SharedApplication.OpenUrl(url);

It shows a pop up with "Cancel" and "Call" button. If user cancels it stays back in the app, if user clicks call it initiates a call. I would like to get the click action if user made a call or canceled it. Is there a way to get that status

回答1:

On iOS 10+ We can use CXCallObserver to capture the event when user make a phone call like:

//Make sure both CXCallObserver and ObserverDelegate a strong reference
private CXCallObserver callObserver;
private MyCallObserverDelegate myCallDelegate;

callObserver = new CXCallObserver();
myCallDelegate = new MyCallObserverDelegate();
callObserver.SetDelegate(myCallDelegate, null);

Implement the delegate for CXCallObserver:

public class MyCallObserverDelegate : CXCallObserverDelegate
{
    public override void CallChanged(CXCallObserver callObserver, CXCall call)
    {
        Console.WriteLine(call.Outgoing);
        Console.WriteLine(call.HasConnected);
        Console.WriteLine(call.OnHold);
        Console.WriteLine(call.HasEnded);
    }
}

But unfortunately, it will not fire when user click cancel.

After user click the button(cancel or call), the app will fire DidBecomeActiveNotification, so I recommend you create a delay method when DidBecomeActiveNotification fires. Then we can detect which button user clicks:

NSNotificationCenter.DefaultCenter.AddObserver(UIApplication.DidBecomeActiveNotification, async (notification) =>
{
    await Task.Delay(500);
    detectCalling();
});

In early time we can define a field bool isDialing = false, if CallChanged() fires set it true. At last we can detect the field in detectCalling();.