void AddressCombobox_GotFocus(object sender, System.Windows.RoutedEventArgs e)
        {
            if (_dropdown == null)
            {
                _dropdown = new Popup();
                _dropdown.AllowsTransparency = true;
                _dropdown.MouseLeave += _dropdown_MouseLeave;
                _dropdown.MouseEnter += _dropdown_MouseEnter;
                var addrpop = new AddressPopup();
                addrpop.Effect = new DropShadowEffect
                {
                    ShadowDepth = 3
                };
                addrpop.SelectedCallback = (v) =>
                {
                    _dropdown.IsOpen = false;
                    this.Text = v;
                    this.ToolTip = AddressConverter.AddressCodeToAddress(v);
                };
                _dropdown.Child = addrpop;
            }

            var ele = sender as FrameworkElement;
            var pos = ele.PointToScreen(new Point(0, this.ActualHeight));
            _dropdown.VerticalOffset = pos.Y;
            _dropdown.HorizontalOffset = pos.X;
            _dropdown.IsOpen = true;
        }
        void AddressCombobox_GotFocus(object sender, System.Windows.RoutedEventArgs e)
        {
            if (_dropdown == null)
            {
                _dropdown = new Popup();
                _dropdown.AllowsTransparency = true;
                _dropdown.MouseLeave        += _dropdown_MouseLeave;
                _dropdown.MouseEnter        += _dropdown_MouseEnter;
                var addrpop = new AddressPopup();
                addrpop.Effect = new DropShadowEffect
                {
                    ShadowDepth = 3
                };
                addrpop.SelectedCallback = (v) =>
                {
                    _dropdown.IsOpen = false;
                    this.Text        = v;
                    this.ToolTip     = AddressConverter.AddressCodeToAddress(v);
                };
                _dropdown.Child = addrpop;
            }

            var ele = sender as FrameworkElement;
            var pos = ele.PointToScreen(new Point(0, this.ActualHeight));

            _dropdown.VerticalOffset   = pos.Y;
            _dropdown.HorizontalOffset = pos.X;
            _dropdown.IsOpen           = true;
        }