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

你是对某一表格读写吧？
osheet.Range("A").Value是读取  
再说你这个也没指定那个表格 默认读取sheet1
再说也应该是
dim str1 as string
str1=osheet.Range("A1").Value 'A是列号 1是行号
正确的写法
dim str1 as string
AppXls.Workbooks(1).Sheets("Sheet1").Cells(1, 1).Value = "这是写入的"    '这是写入  用Cells(A, 1)也可
str1 = AppXls.Workbooks(1).Sheets("Sheet1").Cells(1, 1).Value      '这是读取  用Cells(A, 1)也可
MsgBox(str1 )
虽然没用过VB net 应该和vb语法很接近 C#也差不多是这样