VB for 网络连接相关

'拨号/断网
Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" (ByVal hwnd As Long, ByVal lpOperation As String, ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Long) As Long

Private Declare Function InternetDial Lib "wininet.dll" (ByVal hwndParent As Long, ByVal lpszConnectoid As String, ByVal dwFlags As Long, lpdwConnection As Long, ByVal dwReserved As Long) As Long
Private Declare Function InternetHangUp Lib "wininet.dll" (ByVal dwConnection As Long, ByVal dwReserved As Long) As Long
Private Declare Function InternetAutodial Lib "wininet.dll" (ByVal dwFlags As Long, ByVal dwReserved As Long) As Long
Private Declare Function InternetAutodialHangup Lib "wininet.dll" (ByVal dwReserved As Long) As Long
Private Const INTERNET_DIALSTATE_DISCONNECTED = 1
Private Const INTERNET_AUTODIAL_FORCE_ONLINE = 1
Private Const INTERNET_AUTODIAL_FORCE_UNATTENDED = 2
Private Const INTERNET_DIAL_UNATTENDED = &H8000
Private Handle As Long

'网络状态
Private Declare Function InternetGetConnectedStateEx Lib "wininet.dll" Alias "InternetGetConnectedStateExA" (ByRef lpdwFlags As Long, ByVal lpszConnectionName As String, ByVal dwNameLen As Long, ByVal dwReserved As Long) As Long
Private Declare Function InternetGetConnectedState Lib "wininet.dll" (ByRef dwFlags As Long, ByVal dwReserved As Long) As Long
Private Const INTERNET_CONNECTION_MODEM As Long = &H1      '本系统使用调制解调器与因特网相连
Private Const INTERNET_CONNECTION_LAN As Long = &H2        '本系统通过LAN与因特网相连
Private Const INTERNET_CONNECTION_PROXY As Long = &H4      '本系统使用proxy代理服务器与因特网相连
Private Const INTERNET_CONNECTION_MODEM_BUSY As Long = &H8 '未使用
Private Const INTERNET_RAS_INSTALLED As Long = &H10
Private Const INTERNET_CONNECTION_OFFLINE As Long = &H20
Private Const INTERNET_CONNECTION_CONFIGURED As Long = &H40

'枚举网络连接
Private Const RAS_MaxDeviceType = 16
Private Const RAS95_MaxDeviceName = 128
Private Const RAS95_MaxEntryName = 256

Private Type RASENTRYNAME95
    dwSize As Long
    szEntryName(RAS95_MaxEntryName) As Byte
End Type
Private Declare Function RasEnumConnections Lib "rasapi32.dll" Alias "RasEnumConnectionsA" (lprasconn As Any, lpcb As Long, lpcConnections As Long) As Long
Private Declare Function RasEnumEntries Lib "rasapi32.dll" Alias "RasEnumEntriesA" (ByVal reserved As String, ByVal lpszPhonebook As String, lprasentryname As Any, lpcb As Long, lpcEntries As Long) As Long
Private Declare Function RasHangUp Lib "rasapi32.dll" Alias "RasHangUpA" (ByVal hRasConn As Long) As Long


Private Type RASCONN95
    dwSize As Long
    hRasConn As Long
    szEntryName(RAS95_MaxEntryName) As Byte
    szDeviceType(RAS_MaxDeviceType) As Byte
    szDeviceName(RAS95_MaxDeviceName) As Byte
End Type


'拨号
Public Function DialUp(LinkName As String) As Boolean
    InternetDial 0, LinkName, INTERNET_AUTODIAL_FORCE_UNATTENDED, Handle, 0
    DialUp = (Handle <> 0)
End Function


'枚举网络连接
Public Sub EnumConnectName()
    Dim s As Long, l As Long, ln As Long, A As String
    ReDim r(255) As RASENTRYNAME95
    Dim Value() As String
    r(0).dwSize = 264
    s = 256 * r(0).dwSize
    l = RasEnumEntries(vbNullString, vbNullString, r(0), s, ln)
    
    ReDim Value(ln - 1)
    For l = 0 To ln - 1
        A$ = StrConv(r(l).szEntryName(), vbUnicode)
        Value(l) = Left$(A$, InStr(A$, Chr$(0)) - 1)
        
        Combo1.AddItem Value(l) '置入下拉列表框
    Next
    Combo1.ListIndex = 0
End Sub

'断网及当前状态，当mytype为.时返回当前状态 ，为1时断开网络
Private Function outint(mytype As Integer)
    Dim lngRetCode As Long
    Dim lpcb As Long
    Dim lpcConnections As Long
    Dim intArraySize As Integer
    Dim intLooper As Integer
    ReDim lprasconn95(intArraySize) As RASCONN95
    lprasconn95(0).dwSize = 412
    lpcb = 256 * lprasconn95(0).dwSize
    lngRetCode = RasEnumConnections(lprasconn95(0), lpcb, lpcConnections)
    If lngRetCode = 0 Then
        If lpcConnections > 0 Then
            If mytype = 1 Then
                For intLooper = 0 To lpcConnections - 1
                    RasHangUp lprasconn95(intLooper).hRasConn
                Next intLooper
            End If
            outint = True
        Else
            outint = False
        End If
    End If
End Function