Xamarin Forms ListView不断从List<Object>填充数据,而不是只显示一次对象

这个 List<Object> listArticles

List<PlanDefinition> tempListArticles = new List<PlanDefinition>(listArticles)

async protected override void OnAppearing()
        {

            listArticles= articleView.getArticlesFromPlan();    
            PopulateOrderLists(listArticles);

            base.OnAppearing();
        }

        protected override void OnDisappearing()
        {

            base.OnDisappearing();
        }






  private void PopulateOrderLists(List<PlanDefinition> listArticles)
            {
                List<PlanDefinition> tempListArticles = new List<PlanDefinition>(listArticles);
                OrderTemplate prod = new OrderTemplate();



            for (var i = 0; i < tempListArticles.Count; i++)
            {
                  prod = new OrderTemplate();

                prod.BindingContext = tempListArticles[i].Name;
                 OrderInformation.Children.Add(prod);

             }

        }