How to return from ienumerable function in vb.net - vb.net

Question

Public Shared Function GetDataSet() As IEnumerable(Of SerialData)
Dim sCon As New SQLConnect
Dim strsql As String
Dim p As New Control
sCon.sqlAdp = New SqlDataAdapter
strsql = "select serialid," & _
" serialno," & _
" serialdesc," & _
" b.materialname," & _
" b.drawing," & _
" a.workorder," & _
" isnull((select top 1 patno from patternmaster where patid = a.patid),'Not Defined') as patno," & _
" case when a.activeflag = 1 then 'True' else 'False' end as activeflag" & _
" from serialmaster a," & _
" materialmaster b" & _
" where 1 = 1" & _
" and a.materialid = b.materialid" & _
" and b.activeflag = 1"
sCon.sqlCmd.CommandText = strsql
sCon.sqlAdp.SelectCommand = sCon.sqlCmd
sCon.sqlAdp.Fill(sCon.DS, "Listing")
Dim dtTable As DataTable
dtTable = sCon.DS.Tables("Listing")
' For Each row As DataRow In dtTable.Rows
' Return dtTable.AsEnumerable().[Select](Function(row) New With { _
' Key .serialid = row("serialid"), _
' Key .serialno = row("serialno"), _
' Key .serialdesc = row("serialdesc"), _
' Key .materialname = row("materialname"), _
' Key .drawing = row("drawing"), _
' Key .workorder = row("workorder"), _
' Key .patno = row("patno") _
'})
' Next
For Each row As DataRow In dtTable.Rows
p.serialid.Add(row("serialid"))
p.serialno.Add(row("serialno"))
p.serialdesc.Add(row("serialdesc"))
p.materialname.Add(row("materialname"))
p.drawing.Add(row("drawing"))
p.workorder.Add(row("workorder"))
p.patno.Add(row("patno"))
Next
Return p
End Function
Control class:
Public Class Control
Public serialid As New Generic.List(Of String)
Public serialno As New Generic.List(Of String)
Public serialdesc As New Generic.List(Of String)
Public materialname As New Generic.List(Of String)
Public drawing As New Generic.List(Of String)
Public workorder As New Generic.List(Of String)
Public patno As New Generic.List(Of String)
Public result As New Generic.List(Of String)
End Class
ServerSidePro class:
Public Class ServerSidePro
Implements System.Web.IHttpHandler
Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
Dim d As New Control
' Those parameters are sent by the plugin
Dim iDisplayLength = Integer.Parse(context.Request("iDisplayLength"))
Dim iDisplayStart = Integer.Parse(context.Request("iDisplayStart"))
Dim iSortCol = Integer.Parse(context.Request("iSortCol_0"))
Dim iSortDir = context.Request("sSortDir_0")
'Fetch the data from a repository (in my case in-memory)
'Dim p = SerialData.GetDataSet()
Dim p = DirectCast(SerialData.GetDataSet(), IEnumerable(Of SerialData))
' prepare an anonymous object for JSON serialization
Dim aaData2 = p.select(Function(h) New With {h.serialid, h.serialno, h.serialdesc, _
h.materialname, h.drawing, h.workorder, h.patno}).Skip(iDisplayStart).Take(iDisplayLength)
Dim str As New List(Of String())
For Each item In aaData2
Dim arr As String() = New String(6) {item.serialid, item.serialno, item.serialdesc, _
item.materialname, item.drawing, item.workorder, item.patno}
str.Add(arr)
Next
Dim result = New With { _
Key .iTotalRecords = p.Count(), _
Key .iTotalDisplayRecords = p.Count(), _
Key .aaData = str
}
Dim serializer As New JavaScriptSerializer()
Dim json = serializer.Serialize(result)
context.Response.ContentType = "application/json"
context.Response.ClearHeaders()
context.Response.Write(json)
context.Response.End()
'Return d
End Sub
ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable
Get
Return False
End Get
End Property
End Class
How to return dataset from this function it is giving error Unable to cast object of type 'Control' to type 'System.Collections.Generic.IEnumerable'.

Answer 1

Easiest way is to use a List() object. I would restructure your class
Public Class Control
Public LControl As New List(Of Control)
Public serialid As String
Public serialno As String
Public serialdesc As String
Public materialname As String
Public drawing As String
Public workorder As String
Public patno As String
Public result As String
End Class
​