Cannot implicitly convert type to 'System.Collections.Generic.List

Question

I want to populate a viewmodel with a DateTime property, and also a list of categories.

ViewModel:

public class TourCategoryVM
{
    public DateTime Date { get; set; }
    public List<TourCategoryList> TourCategoryList { get; set; }
}

public class TourCategoryList
{
    public int TourCategoryId { get; set; }
    public string TourType { get; set; }
}

Domain model:

public class TourCategory
{
    public int TourCategoryId { get; set; }
    public string TourType { get; set; }
    public virtual ICollection<Tour> Tour { get; set; }
}

I thought I could populate it easily with this code:

        var viewModel = new TourCategoryVM();
        viewModel.TourCategoryList = db.TourCategories();

However, I'm getting the error:

Error 1 Cannot implicitly convert type
System.Data.Entity.DbSet<tb.Models.TourCategory> to
System.Collections.Generic.List<tb.Models.ViewModels.TourCategoryList>

Is it my ViewModel that's wrong?

Answer 1

The db.TourCategories() method does not return a collection of TourCategoryList, so you'll have to do a little more work to convert whatever class TourCategories() returns into a TourCategoryList, using the LINQ Select() method.

viewModel.TourCategoryList = db.TourCategories()
                               .Select(tc => new TourCategoryList
                                             {
                                                 TourCategoryId = tc.TourCategoryId,
                                                 TourType = tc.TourType
                                             })
                               .ToList();

I'm assuming that TourCategories() returns a collection of TourCategory.

---

If I could make one other suggestion, you might want to rename TourCategoryList. I know you're trying to differentiate it from the other TourCategory class, but someone looking at your code might assume (at first glance) that List<TourCategoryList> is a list of lists, just from the name.