如何得知当前计算机是否上网，

[lwk_hlj]

我想编写一个程序，查看本地计算机是否上网，是否断线，

[thinker711]

你可以用VB做：（摘自《VB使用编程百例》）
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
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
则ISCONNECTED=TRUE，表明正在上网。

[shines77]

thinker711: 你是7.11的生日吗？

[monday]

这个问题我以前问过，怎么那时没人说那么多

[土豆]

你可以PING一个已知的地址,如果能ping通,说明上网.

[U皮特U]

CSDN2000上就有，以下是VC源码：
BOOL CApp::IsRASConnected()
{
RASCONN rasconn;
DWORD dNumber, dSize;
rasconn.dwSize = sizeof(RASCONN);
dSize = sizeof(rasconn);
if ( RasEnumConnections(&rasconn, &dSize, &dNumber)!=0)
return FALSE;
if ( dNumber == 0 )
return FALSE;
return TRUE;
}

[Un1]

Private Declare Function InternetGetConnectedState Lib "wininet.dll" (lpdwFlags As Long, ByVal dwReserved As Long) As Boolean


Dim l As Long
If InternetGetConnectedState(l, l) Then
'connected
else
'not connected

[0xFFCD]

我建议你去http://www.kubao.com去看看，那里有源码