OnActivityResult

protected override void OnActivityResult(int requestCode, Result resultCode, Intent data)
        {
            base.OnActivityResult(requestCode, resultCode, data);

            // we have a valid GUID, so handle the task
            if (!string.IsNullOrEmpty(guid) && pendingTasks.TryRemove(guid, out var tcs) && tcs != null)
            {
                if (resultCode == Result.Canceled)
                {
                    tcs.TrySetCanceled();
                }
                else
                {
                    if (resultCode != Result.Ok)
                    {
                        tcs.SetException(new Exception("Activity returned non-OK result code."));
                    }
                    if (data != null && outputUri != null)
                    {
                        data.PutExtra(OutputUriExtra, outputUri);
                    }
                    else if (data == null && outputUri != null)
                    {
                        data = new AndroidIntent();
                        data.PutExtra(OutputUriExtra, outputUri);
                    }

                    tcs.TrySetResult(data);
                }
            }

            // close the intermediate activity
            Finish();
        }