Public Function IsNumbersOnly(chkStr As String) As Boolean
'检测字符串是否全部由数字组成
Dim i As Long
Const AllNumbers = "0123456789"
IsNumbersOnly = True
For i = 1 To Len(chkStr)
If InStr(AllNumbers, Mid(chkStr, i, 1)) = 0 Then
IsNumbersOnly = False
Exit Function
End If
Next i
End Function