Verificare se una Connessione Internet è in corso
In un modulo BAS inserire:
Option Explicit
Public Declare Function RasEnumConnections Lib "RasApi32.dll" Alias "RasEnumConnectionsA" (lpRasCon As Any, lpcb As Long, lpcConnections As Long) As Long
Public Declare Function RasGetConnectStatus Lib "RasApi32.dll" Alias "RasGetConnectStatusA" (ByVal hRasCon As Long, lpStatus As Any) As Long
Public Const RAS95_MaxEntryName = 256
Public Const RAS95_MaxDeviceType = 16
Public Const RAS95_MaxDeviceName = 32
Public Type RASCONN95
dwSize As Long
hRasCon As Long
szEntryName(RAS95_MaxEntryName) As Byte
szDeviceType(RAS95_MaxDeviceType) As Byte
szDeviceName(RAS95_MaxDeviceName) As Byte
End Type
Public Type RASCONNSTATUS95
dwSize As Long
RasConnState As Long
dwError As Long
szDeviceType(RAS95_MaxDeviceType) As Byte
szDeviceName(RAS95_MaxDeviceName) As Byte
End Type
Public Function IsConnected() As Boolean
Dim TRasCon(255) As RASCONN95
Dim lg As Long
Dim lpcon As Long
Dim RetVal As Long
Dim Tstatus As RASCONNSTATUS95
TRasCon(0).dwSize = 412
lg = 256 * TRasCon(0).dwSize
RetVal = RasEnumConnections(TRasCon(0), lg, lpcon)
If RetVal <> 0 Then
MsgBox "ERROR"
Exit Function
End If
Tstatus.dwSize = 160
RetVal = RasGetConnectStatus(TRasCon(0).hRasCon, Tstatus)
If Tstatus.RasConnState = &H2000 Then
IsConnected = True
Else
IsConnected = False
End If
End Function
Per provare la Funzione IsConnected, che restituisce True se si è connessi e False nel caso contrario, creiamo un esempio ad hoc. In un Form mettiamo un Timer ed una Label.
Infine inserire questo codice:
Option Explicit
Private Sub Form_Load()
Timer1.Interval = 500
Timer1.Enabled = True
End Sub
Private Sub Form_Unload(Cancel As Integer)
Timer1.Enabled = False
End Sub
Private Sub Timer1_Timer()
If IsConnected = True Then
Label1 = "Sei Connesso"
Else
Label1 = "Non sei Connesso"
End If
End Sub
Testato su: Windows 98, Windows Me, Windows 2000 Professional