VB怎样把A.txt文件写入另一个空白的B.txt

'执行代码
Private Sub Command1_Click()
Dim str As String
str = ReadFile(App.Path & "\a.txt")
WriteFile App.Path & "\b.txt", str
End Sub

'***************************************************************
'将字符串写入文件函数
Private Sub WriteFile(filePath As String, strTmp As String)
Open filePath For Output As #1
Print #1, strTmp
Close #1
End Sub
'***************************************************************
'读文件返回字符串函数
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
'***************************************************************

这个问题可以很简化,直接用VB里面的文件复制就行了
代码如下:(假设你a.txt在C盘下,b.txt在D盘下)
Private Sub Command1_C