关于VB对文本文件的读取，定位，修改问题！

在程序目录下新建一个文件文档,最好大于5行,并做一个备份,以便修改后进行比较,在窗体上插入个按钮,复制面代码:

'***************************************************************
'将字符串写入文件
Private Sub WriteFile(filePath As String, strTmp As String)
Open filePath For Output As #1
Print #1, strTmp
Close #1
End Sub
'***************************************************************
'读文件返回字符串
Private Function ReadFile(filePath As String) As String
Dim fileStr As String
Open filePath For Input As #1

Do While Not EOF(1)
Line Input #1, tem
fileStr = fileStr & tem & vbCrLf
Loop
Close #1
ReadFile = fileStr
End Function
'***************************************************************

Private Sub Command1_Click()
Dim str As String
Dim k() As String
str = ReadFile(App.Path & "\a.txt")
k = Split(str, vbCrLf)
'文件行数
Print "文件行数为：" & UBo