JQGrid on ASP.Net MVC with VB.Net - vb.net

Question

I am trying to make a JQGrid for a simple table.
After following through with a VB translated version from
http://haacked.com/archive/2009/04/14/using-jquery-grid-with-asp.net-mvc.aspx
from
http://www.qa.downappz.com/questions/jqgrid-sorting-in-vb-net-mvc-app.html
I modified it to my own database and came up with this function
Public Function SelectGridData(ByVal sidx As String, ByVal sord As String, ByVal page As Integer, ByVal rows As Integer) As ActionResult
Dim context As New IssueDBEntities
Dim pageIndex As Integer = Convert.ToInt32(page) - 1
Dim pageSize As Integer = rows
Dim totalRecords As Integer = context.Issues.Count()
Dim totalPages As Integer = CInt(Math.Ceiling(CSng(totalRecords) / CSng(pageSize)))
Dim jsonData = New With { _
.total = totalPages, _
.page = page, _
.records = totalRecords, _
.rows = (From p In context.Issues _
Order By (p.ID & " " & sord) _
Select New With {.id = p.ID, .cell = _
{p.ID, p.Image_Path, p.Magazine_Type,p.Magazine_Path}}).ToArray()}
Return Json(jsonData, JsonRequestBehavior.AllowGet)
End Function
The grid does show up without any data, and the system throws an error
The error description says
"Unable to cast the type 'System.Int32' to type 'System.Object'. LINQ to Entities only supports casting Entity Data Model primitive types."
Any help is appreciated, if this is due to some basic misunderstanding, please guide me, I am willing to do some hard work.
Thank you
Edit: The code that finally worked as per Oleg's Suggestion
Dim Simple_Object As IQueryable(Of Object)
Dim Second_Simple_Object As IQueryable(Of Object)
Dim My_Array As Array
Dim My_Second_Array As Array
Simple_Object = From p In Context.Issues _
Order By (p.ID & " " & sord) _
Select New With {p.ID, p.Image_Path, p.Magazine_Type, p.Magazine_Path}
My_Array = Simple_Object.ToArray()
Second_Simple_Object = From p In Context.Issues _
Order By (p.ID & " " & sord) _
Select New With {p.ID}
My_Second_Array = Second_Simple_Object.ToArray()
Dim My_Result(0) As My_Record_Type
For i = 0 To My_Array.GetLength(0) - 1
If i > 0 Then
ReDim Preserve My_Result(i)
End If
My_Result(i) = New My_Record_Type
My_Result(i).id = CInt(My_Second_Array(i).ID)
My_Result(i).Cell = {My_Array(i).ID.ToString, My_Array(i).Image_Path.ToString, _
My_Array(i).Magazine_Type.ToString, My_Array(i).Magazine_Path.ToString}
Next
Class My_Record_Type
Public id As Integer
Public Cell As String()
End Class

Answer 1

You try to fill rows property in one step. The problem is that you use Entity Framework which have some restrictions in the conversion of the data types. You can solve the problem if you first make query to get the items which you need without any data conversion and save intermediate results as List of items. After that you can make another LINQ Query where you include explicit conversion of p.ID to string. Moreover your current code don't use any paging of data. So the user will never seen more as the first page if you don't use loadonce: true.
It's difficult for me to write correct code in VB without debugging it. I use C# instead since last years. I recommend you to look at the answer for more information. It contains implementation of the server side filtering. If you don't need it and remove the corresponding code the rest code will be very short and I hope it will be easy to understand.

Answer 2

Here is complete sample of JQgrid with ASP.NET MVC 3 + C# (you can convert it to vb.net)
http://www.dotnetacademy.blogspot.in/2012/04/using-jqgrid-in-aspnet-mvc-3.html