using vb.net export a datatable to Excel and save as file

Export a datatable to Excel and save as file

  Dim CurrentCI As System.Globalization.CultureInfo = System.Threading.Thread.CurrentThread.CurrentCulture
        System.Threading.Thread.CurrentThread.CurrentCulture = New System.Globalization.CultureInfo("en-US")

        If (tmpDataTable Is Nothing) Then
            Return
        End If

        Dim rowNum As Integer = tmpDataTable.Rows.Count
        Dim columnNum As Integer = tmpDataTable.Columns.Count
        Dim rowIndex As Integer = 1
        Dim columnIndex As Integer = 0

        Dim xlApp As Excel.Application = New ApplicationClass()
        xlApp.DefaultFilePath = ""
        xlApp.DisplayAlerts = True
        xlApp.SheetsInNewWorkbook = 1
        Dim xlBook As Workbook = xlApp.Workbooks.Add(True)

        '将DataTable的列名导入Excel表第一行
        Dim dc As DataColumn
        For Each dc In tmpDataTable.Columns
            columnIndex = columnIndex + 1
            xlApp.Cells(rowIndex, columnIndex) = dc.ColumnName
        Next


        '将DataTable中的数据导入Excel中
        Dim i As Integer = 0
        For i = 0 To rowNum - 1

            rowIndex = rowIndex + 1
            columnIndex = 0
            Dim j As Integer = 0
            For j = 0 To columnNum - 1
                columnIndex = columnIndex + 1
                xlApp.Cells(rowIndex, columnIndex) = Convert.ToString(tmpDataTable.Rows(i)(j))
            Next
        Next

        'xlBook.SaveCopyAs(HttpUtility.UrlDecode(strFileName, System.Text.Encoding.UTF8));
        xlBook.SaveCopyAs(strFileName)

        End