Excel Process not closing in VB.net

Question

I am creating an excel file using interop.excel and the process is not closing. This is the code i am trying to use.

 Private Sub converToExcel(fileLoc As String, ds As DataSet)
    Dim xlApp As Excel.Application
    Dim xlWorkBook As Excel.Workbook
    Dim xlWorkBooks As Excel.Workbooks
    Dim xlWorkSheet As Excel.Worksheet
    Dim misValue As Object = System.Reflection.Missing.Value
    Dim i As Integer
    Dim j As Integer

    xlApp = New Excel.Application
    xlWorkBooks = xlApp.Workbooks
    xlWorkBook = xlWorkBooks.Add(misValue)
    xlWorkSheet = xlWorkBook.Sheets("sheet1")

    For i = 0 To ds.Tables(0).Rows.Count - 1
        For j = 0 To ds.Tables(0).Columns.Count - 1
            xlWorkSheet.Columns.NumberFormat = "@"
            xlWorkSheet.Cells(i + 1, j + 1) = String.Format("{0}", ds.Tables(0).Rows(i).Item(j).ToString())
        Next
    Next

    xlWorkSheet.SaveAs(fileLoc)
    xlWorkBook.Close()
    xlApp.Quit()

    releaseObject(xlWorkSheet)
    releaseObject(xlWorkBook)
    releaseObject(xlWorkBooks)
    releaseObject(xlApp)

End Sub
Private Sub releaseObject(ByVal obj As Object)
    Try
        System.Runtime.InteropServices.Marshal.ReleaseComObject(obj)
        obj = Nothing
    Catch ex As Exception
        obj = Nothing
    Finally
        GC.Collect()
    End Try
End Sub

I think i am missing a COM object but cant seem to find a solution. Also as a note, this is running on 64-bit Windows 8. Any help would be great! Thanks

Answer 1

'Get the PID from the wHnd and kill the process.
' open the spreadsheet
ImportFileName = OpenFileDialog1.FileName
excel = New Microsoft.Office.Interop.Excel.ApplicationClass
wBook = excel.Workbooks.Open(ImportFileName)
hWnd = excel.Hwnd
Dim id As Integer = GetWindowThreadProcessId(hWnd, ExcelPID)

---

Sub CloseExcelFile()
        Try
            ' first try this
            wBook.Saved = True
            wBook.Close()
            excel.Quit()

            ' then this.
            System.Runtime.InteropServices.Marshal.ReleaseComObject(excel)
            excel = Nothing

            ' This appears to be the only way to close excel!
            Dim oProcess As Process
            oProcess = Process.GetProcessById(ExcelPID)
            If oProcess IsNot Nothing Then
                oProcess.Kill()
            End If

        Catch ex As Exception
            excel = Nothing
        Finally
            GC.Collect()
        End Try
    End Sub

Answer 2

Dim xlp() As Process = Process.GetProcessesByName("EXCEL")

 For Each Process As Process In xlp
   Process.Kill()
     If Process.GetProcessesByName("EXCEL").Count = 0 Then
       Exit For
     End If
 Next