Question

I am trying to do something similar to this sample code from Phil Haack to VB, and LINQ Orderby is giving me problems – and I can’t figure out how to do this. Entire method posted for completenes.

This is the C# version:

    public ActionResult DynamicGridData(string sidx, string sord, int page, int rows)
    {
        var context = new HaackOverflowDataContext();
        int pageIndex = Convert.ToInt32(page) - 1;
        int pageSize = rows;
        int totalRecords = context.Questions.Count();
        int totalPages = (int)Math.Ceiling((float)totalRecords / (float)pageSize);

        var questions = context.Questions.OrderBy(sidx + " " + sord).Skip(pageIndex * pageSize).Take(pageSize);

        var jsonData = new
        {
            total = totalPages,
            page = page,
            records = totalRecords,
            rows = (
                from question in questions
                select new
                {
                    i = question.Id,
                    cell = new string[] { question.Id.ToString(), question.Votes.ToString(), question.Title }
                }).ToArray()
        };
        return Json(jsonData);
    }

My problem is with this line…:

var questions = context.Questions.OrderBy(sidx + " " + sord).Skip(pageIndex * pageSize).Take(pageSize);

In VB.Net OrderBy does not accept a string as value – and it seems to do that in C# (or I am missing something).

(Please not the use of VAR is not the issue here, I have that covered. 🙂 )

Edit:
This is the error I get (I simply cannot compile):

Overload resolution failed because no accessible ‘OrderBy’ can be called with these arguments…

Screenshot of complete error message:

Edit2:

More information, as requested.
sidx contains the name of a column to sort by
sord contains asc or desc

The VB-code:

Function MemberData(ByVal sidx As String, ByVal sord As String, ByVal page As Integer, ByVal rows As Integer) As JsonResult

    Dim allRecords As IQueryable(Of Models.Member) = Me.MemberRepository.FindAllMembers
    Dim currentPageRecords As IQueryable(Of Models.Member)
    Dim pageIndex As Integer = page - 1
    Dim pageSize As Integer = rows
    Dim totalRecords As Integer = allRecords.Count
    Dim totalPages As Integer = CInt(Math.Ceiling(totalRecords / pageSize))

    Dim orderBy As String = sidx + " " + sord

    currentPageRecords = allRecords.OrderBy(Function(m) orderBy).Skip(pageIndex * pageSize).Take(pageSize)

    Dim jsonData = New With { _
          .total = totalPages, _
          .page = page, _
          .records = totalRecords, _
          .rows = New ArrayList _
        }

    For Each member As Models.Member In currentPageRecords
        jsonData.rows.Add(New With {.id = member.MemberId, .cell = GenerateCellData(member)})
    Next

    Return Json(jsonData)

End Function

Answer 1

Is it possible he’s using Dynamic Linq? With dynamic linq you can pass string to the OrderBy methods as well as many other of the IEnumerable extension methods.