VB6利用正则表达式验证IP地址合法性

Public Function isValidIpAddress(strIpAddress As String) As Boolean
Dim reg As New RegExp, i As Integer
reg.IgnoreCase = True
reg.Global = True
reg.MultiLine = True
reg.Pattern = "^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$"

isValidIpAddress = reg.Test(strIpAddress)

If isValidIpAddress = True Then
Dim strArr() As String
strArr = Split(strIpAddress, ".")

For i = 0 To UBound(strArr)
isValidIpAddress = isValidIpAddress And isValidIpNumber(strArr(i))
Next i
End If
End Function
Private Function isValidIpNumber(strNumber As String)
Dim ipnum As Integer
ipnum = CInt(strNumber)

isValidIpNumber = (ipnum < 256)
End Function