Usage contains in linq

Question

I have a filtered list that returns all individual identifiers from MenuTable

  var _parentList = _employee.Designation.Role.MenuRoles
                                                .Select(x => new
                                                {
                                                    MenuParentID = x.Menu.ParentID
                                                })
                                                .DistinctBy(x => x.MenuParentID)
                                                .OrderBy(x => x.MenuParentID)
                                                .ToList();

I want to select all the items from menutablethat are in_parentList

This is what I tried and an error appears _parentList.Contains(x.Id)that saysBest overloaded match for System.Generic.contains has some invalid arguments.

 MenuParentList = _db.Menus.Where(x => _parentList.Contains(x.Id))
                           .Select(x => new SMS.Models.ViewModel.DashboardVM.MenuParent
                           {
                               MenuParentID = x.Id,
                               MenuParentName = x.MenuName
                           })
                           .ToList()

Any help would be appreciated

Answer 1

Cf. this code:

.Select(x => new
{
    MenuParentID = x.Menu.ParentID
})

This results in a list of anonymous objects with one property called MenuParentID, instead of a list of integers. The compiler creates a type for you that looks structurally as follows (note that the compiler generates the name of the inapplicable class behind the scenes instead AnonymousType1, but you get the idea):

class AnonymousType1
{
    public int MenuParentID {get;set;}
}

_parentList List<AnonymousType1>.

:

var _parentList = _employee.Designation.Role.MenuRoles
                       .Select(x => x.Menu.ParentID)
                       .Distinct()
                       .OrderBy(id => id)
                       .ToList();

_parentList List<int>.

msdn: https://msdn.microsoft.com/en-us/library/bb397696.aspx