How to connect the default dialup in XP or seven Using C#?

Question

I have a dialup connection in my system namely "Personal Internet Movil" and i need to connect and disconnect this connection using C#.

Answer 1

You can use this code, and these import statements and enums do detect a connection, fire up the Dialup box, and then hangup when you're done. If you don't want the user to select the dialup connection then user InternetAutodial/InternetAutodialHangup pair rather. But Please note that this pair will ONLY use whatever dialup is set as the default.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//BEGIN
InternetConnectionState flags = 0;
int nConnection = 0;
bool bInternet = InternetGetConnectedState(ref flags,0);
if (bInternet == false)
{
 //Not Connected
 if (flags == 0)
 {
   //Do something to tell the user to install some internet connection
 }
 int nResult = InternetDial(IntPtr.Zero,"",(int)InternetDialFlags.INTERNETDIALFORCEPROMPT , ref nConnection , 0);
 switch(nResult)
 {
   case 87://Bad Parameter for InternetDial - Couldn't Connect";
     break;
   case 668://No Connection for InternetDial - Couldn't Connect";
     break;
   case 631://User Cancelled Dialup
     break;
   default://Unknown InternetDial Error
     break;
   case 0://Connection Succeeded
     break;
 }
 //Do whatever you need to do on the internet (send mail etc)
 InternetHangUp(nConnection,0);
 //DONE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[DllImport("wininet.dll",CharSet=CharSet.Auto)]
static extern bool InternetGetConnectedState(ref InternetConnectionState lpdwFlags, int dwReserved);
[Flags]
enum InternetConnectionState: int
{
   INTERNETCONNECTIONMODEM = 0x1,
   INTERNETCONNECTIONLAN = 0x2,
   INTERNETCONNECTIONPROXY = 0x4,
   INTERNETRASINSTALLED = 0x10,
   INTERNETCONNECTIONOFFLINE = 0x20,
   INTERNETCONNECTIONCONFIGURED = 0x40
}
[DllImport("wininet.dll",CharSet=CharSet.Auto)]
static extern int InternetDial(IntPtr hwndParent,[MarshalAs(UnmanagedType.LPStr)] string strConnection,[MarshalAs(UnmanagedType.U4)]int dwFlags,ref int dwConnection,int dwReserved);
[Flags]
enum InternetDialFlags: int
{
   INTERNETDIALFORCEPROMPT    =0x2000,
   INTERNETDIALSHOWOFFLINE    =0x4000,
   INTERNETDIAL_UNATTENDED      =0x8000
}
[DllImport("wininet.dll",CharSet=CharSet.Auto)]
static extern int InternetHangUp([MarshalAs(UnmanagedType.U4)] int nConnection,[MarshalAs(UnmanagedType.U4)]int dwReserved);