'CLASSE ICOMPARER PERSONALIZZATA CHE ORDINA IN STILE WINDOWS EXPLORER

 Public Class CustomComparer
        Implements IComparer
        Private Position As Integer
        Private Order As Integer = 1
        Private NomeColonna As String = ""
        Public Sub New(_NomeColonna As String, Optional ByVal Ascending As Boolean = True)
            NomeColonna = _NomeColonna
            If Not Ascending Then
                Order = -1
            End If
        End Sub

        Public Function Compare(ByVal x As Object, ByVal y As Object) As Integer Implements System.Collections.IComparer.Compare
            Dim ValoreX As String = CType(x, DatiItemLView_Dati).NomeFile
            Dim ValoreY As String = CType(y, DatiItemLView_Dati).NomeFile

            Dim res1() As String = System.Text.RegularExpressions.Regex.Split(ValoreX.ToString, "(\d+)", System.Text.RegularExpressions.RegexOptions.IgnoreCase)
            Dim reswithempty() As String = System.Text.RegularExpressions.Regex.Split(ValoreY.ToString, "(\d+)", System.Text.RegularExpressions.RegexOptions.IgnoreCase)
            Dim res2(0) As String
            Dim c As Integer = 0
            For Each item In reswithempty ' I dont like this
                If item <> String.Empty Then
                    ReDim Preserve res2(c)
                    res2(c) = item
                    c += 1
                End If
            Next
            Position = 0
            For Each xstr In res1
                If res2.Length > Position Then
                    If xstr <> String.Empty Then
                        If Not IsNumeric(xstr) AndAlso Not IsNumeric(res2(Position)) Then
                            Dim intresult As Integer = String.Compare(xstr, res2(Position), True)
                            If intresult <> 0 Then
                                Return intresult * Order
                            Else
                                Position += 1
                            End If
                        ElseIf IsNumeric(xstr) And Not IsNumeric(res2(Position)) Then
                            Return -1 * Order
                        ElseIf Not IsNumeric(xstr) And IsNumeric(res2(Position)) Then
                            Return 1 * Order
                        ElseIf IsNumeric(xstr) And IsNumeric(res2(Position)) Then
                            Dim res As Integer = Decimal.Compare(Decimal.Parse(xstr), Decimal.Parse(res2(Position)))
                            If res = 0 Then
                                Position += 1
                            Else
                                Return res * Order
                            End If
                        End If
                    End If
                Else
                    Return -1 * Order
                End If
            Next
            Return 1 * Order
        End Function
    End Class



'HANDLE SULL'EVENTO SORTING PER ESEGUIRE IL SORTING PERSONALIZZATO


    Private Sub DataGrid1_Sorting(sender As Object, e As Microsoft.Windows.Controls.DataGridSortingEventArgs) Handles DataGrid1.Sorting
        Dim column As Microsoft.Windows.Controls.DataGridColumn = e.Column

        Dim comparer As IComparer = Nothing
        e.Handled = True

        Dim direction As ListSortDirection = If((column.SortDirection <> ListSortDirection.Ascending), ListSortDirection.Ascending, ListSortDirection.Descending)
        column.SortDirection = direction


        Dim lcv As ListCollectionView = DirectCast(CollectionViewSource.GetDefaultView(DataGrid1.ItemsSource), ListCollectionView)
        comparer = New CustomComparer(column.SortMemberPath, IIf(direction = ListSortDirection.Ascending, True, False))

        lcv.CustomSort = comparer
    End Sub