Alex Mogurenko`s Blog

Some posts ago i wrote about using RAS to establish internet connection in that post i mentioned about Connection Manager API. Full description you can find on MSDN, but in most cases developers use 2 functions:

ConnMgrEstablishConnection
ConnMgrReleaseConnection

So to establish connection we need just fill one struct and call ConnMgrEstablishConnection. Thats easy, isnt it?

public bool Connect()
{
ConnectionInfo connInfo_ = new ConnectionInfo();
connInfo_.cbSize = Marshal.SizeOf(connInfo_);
connInfo_.dwFlags = 0;
connInfo_.dwParams = 0x1;
connInfo_.guidDestNet = new Guid("436EF144-B4FB-4863-A041-8F905A62C572");
connInfo_.dwPriority = 0x08000;
connInfo_.bExclusive = 0;
connInfo_.bDisabled = 0;
connInfo_.hWnd = IntPtr.Zero;
connInfo_.lParam = 0;

IntPtr conn_ = IntPtr.Zero; //we dont need to save it because it aint work
return ConnMgrEstablishConnection(connInfo_, out conn_) == 0;
}

I dont know why, but ConnMgrReleaseConnection aint work for me i returns success result, but connection still established, so to Disconnect i still use RAS, but how? i can call RasHangUp if i dont know Connection Handle, so we need to use RasEnumConnections to get it and then call RasHangUp

//using ras to disconnect
public static void Disconnect()
{
RasConn[] rconn_ = new RasConn[1]; //as a rule 1 connection is enough
int out_ = Marshal.SizeOf(typeof(RasConn));
int cout_ = 1;

rconn_[0].dwSize = out_;
rconn_[0].szEntryName = null;

RasEnumConnections(rconn_, ref out_, out cout_);

if (cout_ > 0)
{
RasHangUp(rconn_[0].hRasconn);
System.Threading.Thread.Sleep(3000); //msdn says that we should do that
}
}

Sources you can donload here

Filed under: Programming