vb.net 求助，请大家帮忙。谢谢

Imports excel = Microsoft.Office.Interop.Excel

Imports System.IO
Public Class Form1
    Private Sub Button1_Click(sender As Object, e As EventArgs)

    End Sub
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    End Sub
    Private Sub Button1_Click_1(sender As Object, e As EventArgs) Handles Button1.Click
        Dim fileTest As String = "c:\Temp\ExcelTest\test.xlsx"
        If File.Exists(fileTest) Then
            File.Delete(fileTest)
        End If

        Dim oexcel As Object
        oexcel = CreateObject("excel.Application")
        Dim obook As excel.Workbook
        Dim osheet As excel.Worksheet

        obook = oexcel.Workbooks.Add
        osheet = oexcel.Worksheets(1)

        osheet.Name = "test name"
        osheet.Range("A").Value = "button 1"
        obook.SaveAs(fileTest)
        obook.Close()
        obook = Nothing
        oexcel.Quit()
        oexcel = Nothing
    End Sub
End Class

谢谢.

一楼楼主您好，希望楼主能帮帮忙。
如何把文本框中的数据保存到excel，不能覆盖，而是能保存到下一行，不影响前几行保存的数据
谢谢。