Excelオブジェクトの解放

Private Shared Sub OneMethod()
    ' 必要な変数は Try の外で宣言する
    Dim xlApp As Excel.Application

    ' COM オブジェクトの解放を保証するために Try 〜 Finally を使用する
    Try
        xlApp = New Excel.Application()
        xlApp.Visible = True
        xlApp.DisplayAlerts = False

        Dim xlBooks As Excel.Workbooks = xlApp.Workbooks

        Try
            Dim xlBook As Excel.Workbook = xlBooks.Open("C:\Hoge.xls")

            Try
                Dim xlSheets As Excel.Sheets = xlBook.Worksheets

                Try
                    Dim xlSheet1 As Excel.Worksheet = DirectCast(xlSheets(1), Excel.Worksheet)

                    Try
                        Dim xlCells As Excel.Range = xlSheet1.Cells

                        Try
                            For i As Integer = 1 To 10
                                Dim xlRange As Excel.Range

                                Try
                                    xlRange = DirectCast(xlCells(i, 1), Excel.Range)
                                    xlRange.Value = i.ToString()

                                    Dim xlNames As Excel.Names = xlBook.Names

                                    Try
                                        Dim xlName As Excel.Name = xlNames.Add("name1", RefersToR1C1:="Sheet1!R1C1:R" & i.ToString() & "C1")

                                        Try
                                            '/ xlName を使用
                                        Finally
                                            If Not xlName Is Nothing Then
                                                System.Runtime.InteropServices.Marshal.ReleaseComObject(xlName)
                                            End If
                                        End Try
                                    Finally
                                        If Not xlNames Is Nothing Then
                                            System.Runtime.InteropServices.Marshal.ReleaseComObject(xlNames)
                                        End If
                                    End Try
                                Finally
                                    If Not xlRange Is Nothing Then
                                        System.Runtime.InteropServices.Marshal.ReleaseComObject(xlRange)
                                    End If
                                End Try
                            Next i
                        Finally
                            If Not xlCells Is Nothing Then
                                System.Runtime.InteropServices.Marshal.ReleaseComObject(xlCells)
                            End If
                        End Try
                    Finally
                        If Not xlSheet1 Is Nothing Then
                            System.Runtime.InteropServices.Marshal.ReleaseComObject(xlSheet1)
                        End If
                    End Try
                Finally
                    If Not xlSheets Is Nothing Then
                        System.Runtime.InteropServices.Marshal.ReleaseComObject(xlSheets)
                    End If
                End Try
            Finally
                If Not xlBook Is Nothing Then
                    Try
                        xlBook.Close()
                    Finally
                        System.Runtime.InteropServices.Marshal.ReleaseComObject(xlBook)
                    End Try
                End If
            End Try
        Finally
            If Not xlBooks Is Nothing Then
                System.Runtime.InteropServices.Marshal.ReleaseComObject(xlBooks)
            End If
        End Try
    Finally
        If Not xlApp Is Nothing Then
            Try
                xlApp.Quit()
            Finally
                System.Runtime.InteropServices.Marshal.ReleaseComObject(xlApp)
            End Try
        End If
    End Try
End Sub