netdetect.bas

来自「用VISUAL BASIC编制的,一个好用的扫描器」· BAS 代码 · 共 135 行

Attribute VB_Name = "netdetect"
Option Explicit


Public Declare Function InternetGetConnectedState _
    Lib "wininet.dll" (ByRef lpdwFlags As Long, _
    ByVal dwReserved As Long) As Long
    'Local system uses a modem to connect to
    '     the Internet.
    Public Const INTERNET_CONNECTION_MODEM As Long = &H1
    'Local system uses a LAN to connect to t
    '     he Internet.
    Public Const INTERNET_CONNECTION_LAN As Long = &H2
    'Local system uses a proxy server to con
    '     nect to the Internet.
    Public Const INTERNET_CONNECTION_PROXY As Long = &H4
    'No longer used.
    Public Const INTERNET_CONNECTION_MODEM_BUSY As Long = &H8
    Public Const INTERNET_RAS_INSTALLED As Long = &H10
    Public Const INTERNET_CONNECTION_OFFLINE As Long = &H20
    Public Const INTERNET_CONNECTION_CONFIGURED As Long = &H40
    'InternetGetConnectedState wrapper funct
    '     ions


Public Function IsNetConnectViaLAN() As Boolean
    Dim dwflags As Long
    'pass an empty varialbe into which the A
    '     PI will
    'return the flags associated with the co
    '     nnection
    Call InternetGetConnectedState(dwflags, 0&)
    'return True if the flags indicate a LAN
    '     connection
    IsNetConnectViaLAN = dwflags And INTERNET_CONNECTION_LAN
End Function


Public Function IsNetConnectViaModem() As Boolean
    Dim dwflags As Long
    'pass an empty varialbe into which the A
    '     PI will
    'return the flags associated with the co
    '     nnection
    Call InternetGetConnectedState(dwflags, 0&)
    'return True if the flags indicate a mod
    '     em connection
    IsNetConnectViaModem = dwflags And INTERNET_CONNECTION_MODEM
End Function


Public Function IsNetConnectViaProxy() As Boolean
    Dim dwflags As Long
    'pass an empty varialbe into which the A
    '     PI will
    'return the flags associated with the co
    '     nnection
    Call InternetGetConnectedState(dwflags, 0&)
    'return True if the flags indicate a pro
    '     xy connection
    IsNetConnectViaProxy = dwflags And INTERNET_CONNECTION_PROXY
End Function


Public Function IsNetConnectOnline() As Boolean
    'no flags needed here - the API returns
    '     True
    'if there is a connection of any type
    IsNetConnectOnline = InternetGetConnectedState(0&, 0&)
End Function


Public Function IsNetRASInstalled() As Boolean
    Dim dwflags As Long
    'pass an empty varialbe into which the A
    '     PI will
    'return the flags associated with the co
    '     nnection
    Call InternetGetConnectedState(dwflags, 0&)
    'return True if the falgs include RAS in
    '     stalled
    IsNetRASInstalled = dwflags And INTERNET_RAS_INSTALLED
End Function


Public Function GetNetConnectString() As String
    Dim dwflags As Long
    Dim msg As String
    'build a string for display


    If InternetGetConnectedState(dwflags, 0&) Then


        If dwflags And INTERNET_CONNECTION_CONFIGURED Then
            msg = msg & "Cnnection configured.." & vbCrLf
            End If


        If dwflags And INTERNET_CONNECTION_LAN Then
            msg = msg & "Local system connects via a LAN"
        End If


        If dwflags And INTERNET_CONNECTION_PROXY Then
            msg = msg & ", and uses a proxy server. "
        Else: msg = msg & ""
        End If


        If dwflags And INTERNET_CONNECTION_MODEM Then
            msg = msg & "Local system uses a modem to connect... "
        End If


        If dwflags And INTERNET_CONNECTION_OFFLINE Then
            msg = msg & "Connection offline... "
        End If


        If dwflags And INTERNET_CONNECTION_MODEM_BUSY Then
            msg = msg & "Local system modem is busy with a non-Internet connection. "
        End If


        If dwflags And INTERNET_RAS_INSTALLED Then
            msg = msg & "RAS on."
        End If
    Else
        msg = "Not connected..."
    End If
    GetNetConnectString = msg
End Function