private async System.Threading.Tasks.Task AddTask()
        {
            AreBtnsEn = false;
            string taskName = await Application.Current.MainPage.DisplayPromptAsync("New Task", "Insert new task name:");

            if (String.IsNullOrEmpty(taskName))
            {
                return;
            }
            Models.Task newTask   = new Models.Task(ListID, taskName);
            var         addResult = await n_Restctrl.AddTask(newTask);

            if (addResult.StatusCode == HttpStatusCode.Created)
            {
                await Refresh();
            }
            else if (addResult.StatusCode == HttpStatusCode.Unauthorized)
            {
                await Application.Current.MainPage.DisplayAlert("Sorry", "You do not have permission to do this", "Ok");
            }
            else
            {
                await Application.Current.MainPage.DisplayAlert("Error", "Something went wrong, check your connection", "Ok");
            }

            AreBtnsEn = true;
        }