public static UIView CreateDropList(UIView view, UIPickerView picker, UITextField txtField, List <string> param)
        {
            var choiceModel = new PickerModel((IList <string>)param);
            var imp         = param[0];

            picker = new UIPickerView(new CGRect(0, 44, view.Bounds.Width, 216))
            {
                Model                  = choiceModel,
                BackgroundColor        = UIColor.LightGray,
                ShowSelectionIndicator = true,
                Hidden                 = false,
                AutosizesSubviews      = true,
            };

            var toolHigh = new UIToolbar
            {
                BarStyle               = UIBarStyle.Black,
                Translucent            = true,
                UserInteractionEnabled = true
            };

            toolHigh.SizeToFit();
            var doneHigh = new UIBarButtonItem("Done", UIBarButtonItemStyle.Done,
                                               (ss, ea) =>
            {
                picker.ResignFirstResponder();
                txtField.Text = imp;
                txtField.ResignFirstResponder();
            });

            toolHigh.SetItems(new UIBarButtonItem[] { doneHigh }, true);

            var pickView = new UIView(new CGRect(0, 0, view.Bounds.Width, 260));

            pickView.AddSubviews(new UIView[] { picker, toolHigh });

            choiceModel.PickerChanged += (object sender, PickerChangedEventArgs ea) =>
            {
                imp = ea.SelectedValue;
            };
            return(pickView);
        }