InvokeonMainThread命令未运行

Question

我在PCL中调用UIThread时遇到问题。

我做了一个这样的方法：

       private async void PopulateContent ()
        {

            Task <List <Department>> taskDep = new Task <List<Department>> (() =>
            {
                departments = departmentDal.GetAll();
                return departments.ToList ();
            });
            TaskDep.Start();
            TaskDep.Wait();
            
            PopulateCarouselDeps();

            Task <List<Category>> taskCat = new Task <List <Category>> (() =>
            {
                Categories = categoryDal.GetAllByDepartment (carouselViewDepartments.Item as Department).ToList ();
                return categories.ToList();
            });
            
            TaskCat.Start();
            TaskCat.Wait();
            PopulateCarouselCats();
            Task <List<Product>> taskProd = new Task <List<Product>> (() =>
            {
                Products = productDal.GetAllByCategory (carouselViewCategories.Item Category);
                return products.ToList();
            });
            TaskProd.Start();
            TaskProd.Wait();
            PopulateListViewProducts();
        }

    private void PopulateCarouselDeps ()
    {
            
            Device.BeginInvokeOnMainThread (() => {
                Try
                {
                    carouselViewDepartments.ItemsSource = departments;
                }
                Catch (Exception e) // handle whatever exceptions you expect
                {
                    // Handle exceptions
                }
            });
    }

当我调用PopulateCarouselDeps（）方法时，会发生以下情况：它不会进入try-catch语句块。

因此，Carousel没有填充，我需要它来推广其他内容。

所有流行的方法都非常相似。

有谁知道如何解决这个问题？

THX，