private void ShowDeviceMenu(Button btn)
        {
            if (_deviceWindow.Visibility == Visibility.Visible)
                _activityWindow.Hide();
            var transform = btn.TransformToAncestor(this);
            var rootPoint = transform.Transform(new Point(0, 0));

            _deviceWindow.Show((int)rootPoint.X, _client.DeviceList.Values.ToList());

        }