Link Exception/Error

For a long time, I have been try to do this:

Private Sub Search()
    'DataGrid1.ItemsSource = From k In Globals.Batchs.BatchList Where (CType(k.Category, String).ToLower().Contains(SearchByCategory.Text)) Select k
    Dim tot As List(Of WorkMateLib.BatchLib.BatchItem) = Globals.Batchs.BatchList
    If Not SearchByCategory.Text = "" Then
        tot = From k As WorkMateLib.BatchLib.BatchItem In tot Where CType(k.Category, String).ToLower().Contains(SearchByCategory.Text) Select k
    End If
    If Not SearchByCourse.Text = "" Then
        tot = From k In tot Where (CType(k.CourseName, String).ToLower().Contains(SearchByCourse.Text))
    End If
    If Not SearchByName.Text = "" Then
        tot = From k In tot Where (CType(k.BatchName, String).ToLower().Contains(SearchByName.Text))
    End If
    If Not SearchByYear.Text = "" Then
        tot = From k In tot Where (CType(k.DateStarted, Date).Year.ToString.ToLower.Contains(SearchByYear.Text))
    End If
    DataGrid1.ItemsSource = tot
End Sub

But is keep on throwing the following exception:

Unable to cast object of type 'WhereSelectListIterator`2[WorkMateLib.BatchLib.BatchItem,WorkMateLib.BatchLib.BatchItem]' to type 'System.Collections.Generic.List`1[WorkMateLib.BatchLib.BatchItem]'.

Could you please review and let me know where I am going wrong please. Following is the code for the classes:

Namespace BatchLib
    Public Class BatchItem
        Dim _BatchID As String
        Dim _BatchName As String
        Dim _Category As String
        Dim _CourseID As String
        Dim _CourseName As String
        Dim _StartDate As Date
        Dim _StartDateFormated As String
        Dim _Deleted As Boolean
#Region "Property"
        Property BatchID
            Get
                Return _BatchID
            End Get
            Set(value)
                _BatchID = value
            End Set
        End Property
        Property BatchName
            Get
                Return _BatchName
            End Get
            Set(value)
                _BatchName = value
            End Set
        End Property
        Property Category
            Get
                Return _Category
            End Get
            Set(value)
                _Category = value
            End Set
        End Property
        Property CourseID
            Get
                Return _CourseID
            End Get
            Set(value)
                _CourseID = value
            End Set
        End Property
        Property DateStarted
            Get
                Return _StartDate
        开发者_如何学Python    End Get
            Set(value)
                _StartDate = value
            End Set
        End Property
        Property Deleted
            Get
                Return _Deleted
            End Get
            Set(value)
                _Deleted = value
            End Set
        End Property
        Property CourseName
            Get
                Return _CourseName
            End Get
            Set(value)
                _CourseName = value
            End Set
        End Property
        Property StartDateFormated
            Get
                Return _StartDateFormated
            End Get
            Set(value)
                _StartDateFormated = value
            End Set
        End Property
#End Region
    End Class

    Public Class Batchs
        Public BatchList As New List(Of BatchItem)
        Public Function Contains(ByVal Batchname As String, ByVal CourseID As String)
            For Each k As BatchItem In BatchList
                If k.CourseID = CourseID And k.BatchName = Batchname Then
                    Return True
                    Exit Function
                End If
            Next
            Return False
        End Function
        Public Function Contains(ByVal Batchname As String, ByVal CourseID As String, ByVal BatchID As String)
            For Each k As BatchItem In BatchList
                If k.CourseID = CourseID And k.BatchName = Batchname Then
                    If k.BatchID = BatchID Then
                    Else
                        Return True
                        Exit Function
                    End If
                End If
            Next
            Return False
        End Function
    End Class
End Namespace

Thank you for your efforts. I am new to linq, so I may not be that good at it, your assistant and making me understand the mistake is heartily welcomed.

Exception does say exacly whats ur problem. Linq expression does not return List and its not assignable to List. Try surounding your whole expression in brackets and use ToList()