How to create a Network Connection class that access Remote server?

How to create a Network Connection class that access Remote server?

• Marty McGee

  Hi Durgaprasad Gorti, 
     Tahnsks for reply. What I like to do is create a VPN connection programatically in order my class library which contains my database access, connection, and process will be able to interact with the remote server. Here is some codes I found and modified it, to have fixed ip address, username and password. It does not work. Can you or anyone help me Advanced thanks.
  
  This inside main class
  [code]
  public void Dial()
  {
      if(_Handle!=IntPtr.Zero)
     {
          RASCONNSTATUS status=new RASCONNSTATUS();
          uint res=RasAPI.RasGetConnectStatus(_Handle,status);
        
          if(res==ERROR_INVALID_HANDLE) //res=ERROR_INVALID_HANDLE
             _Handle=IntPtr.Zero;
          else
              return;
      }
      try
      {
             this._Params.szPhoneNumber = "<server ip>";
             this._Params.szUserName = "<username>";
             this._Params.szPassword = "dennispt200508";
             RasAPI.RasCheck(RasAPI.RasDial(null,_Phonebook,_Params,1,_DialNotifyDelegate,ref _Handle));
             RasAPI.RasConnectionNotification(_Handle,this._DisconnEvent.Handle,RASNOTIFICATION.RASCN_Disconnection);
      
             RasAPI.RasDial(null,@"C:\Documents and Settings\All Users\Application Data\Microsoft\Network\Connections\Pbk\rasphone.pbk",_Params,1,_DialNotifyDelegate,ref _Handle);

              StartWatch();

              if (ConnectionState.IsModemConnected())
                  this.statusSend("Connected to 203.201.133.64");
              else
   this.statusSend("Unable to connect.");
       }
       catch(Exception e)
      {
      
      }
  }

  
  private void StartWatch()
  {
        StopWatch();
       this._WatchThread=new Thread(new ThreadStart(RunWatch));
       this._WatchThread.Start();
  }

  private void StopWatch()
  {
        if(this._WatchThread==null)
   return;
        if(this._WatchThread.IsAlive)
        {
   this._StopEvent.Set();
   this._WatchThread.Join();
         }
        this._WatchThread=null;
  }

  private void RunWatch()
  {
         WaitHandle[] handles=new WaitHandle[]{this._StopEvent,this._DisconnEvent};
         int ret;
         this._StopEvent.Reset();
         this._DisconnEvent.Reset();
         while(true)
        {
   ret=WaitHandle.WaitAny(handles);
   if(ret==0)
       break;
   if(ret==1)
   {
         this.OnDisconnected();
          System.Diagnostics.Debug.WriteLine("Dis connected");
              break;
   }
         }
  }

  private void OnConnected()
  {
        if(this.Connected==null)
            return;
       EventArgs args=new EventArgs();
       if(this.SynchronizingObject!=null && this.SynchronizingObject.InvokeRequired)
      {
            this.SynchronizingObject.Invoke(Connected,new object[]{this,args});
       }
       else
       {
              Connected(this,args);
        }
  }

  private void OnDisconnected()
  {
          if(this.Disconnected==null)
          return;
          EventArgs args=new EventArgs();
          if(this.SynchronizingObject!=null && this.SynchronizingObject.InvokeRequired)
          {
   this.SynchronizingObject.Invoke(Disconnected,new object[]{this,args});
           }
            else
            {
   Disconnected(this,args);
            }
  }

  private void OnDialNotify1(IntPtr hrasconn,uint unMsg,RASCONNSTATE rascs,uint dwError,uint dwExtendedError)
  {
           if(this.DialNotify1==null)
   return;
           string msg="";
           if(dwError>0)
           {
  // msg=RasException.Code2RasErrorMessage(dwError);
            }
            else
            {
  // msg=RasConnection.GetRasConnStateMessage(rascs);
             msg = this.GetRasConnStateMessage(rascs);
            }
           RasDialNotify1EventArgs args=new RasDialNotify1EventArgs(hrasconn,unMsg,rascs,dwError,dwExtendedError,msg);
          
           if(this.SynchronizingObject!=null && this.SynchronizingObject.InvokeRequired)
           {
   this.SynchronizingObject.Invoke(DialNotify1,new object[]{this,args});
           }
           else
           {
   DialNotify1(this,args);
            }
            if(args.ConnectionState==RASCONNSTATE.RASCS_Connected)
   OnConnected();
   }

  private string GetRasConnStateMessage(RASCONNSTATE state)
  {
          string ret="";
          if(_Res!=null)
   ret=(string)_Res.GetObject(state.ToString().Trim());
           return ret;
  }

  [Browsable(false),Description("get or set SynchronizingObject")]
  public ISynchronizeInvoke SynchronizingObject
  {
     get
    {
            if(_SynchronizingObject==null)
             {
   if(this.DesignMode)
   {
         IDesignerHost dh=this.GetService(typeof(IDesignerHost)) as IDesignerHost;
         if(dh!=null)
         {
    _SynchronizingObject=dh.RootComponent as ISynchronizeInvoke;
          }
   }
              }
             return _SynchronizingObject;
       }
       set
       {
              _SynchronizingObject=value;
       }
  }
   [/code]

  Inside another class
  [code]
  internal sealed class RasAPI
   {
    private RasAPI(){}

    [DllImport("rasapi32.dll",CharSet=CharSet.Auto)]  
    public extern static uint RasDial(
     [In]RASDIALEXTENSIONS lpRasDialExtensions,
     // pointer to function extensions data
     [In]string lpszPhonebook,  // pointer to full path and file
     //  name of phone-book file
     [In]RASDIALPARAMS lpRasDialParams,
     // pointer to calling parameters data
     uint dwNotifierType,   // specifies type of RasDial event handler
     Delegate lpvNotifier,     // specifies a handler for RasDial events
     ref IntPtr lphRasConn   // pointer to variable to receive
     //  connection handle
     );

    [DllImport("rasapi32.dll",CharSet=CharSet.Auto)]
    public extern static uint RasGetConnectStatus(
     IntPtr hrasconn,  // handle to RAS connection of interest
     [In,Out]RASCONNSTATUS lprasconnstatus
     // buffer to receive status data
     );

    [DllImport("rasapi32.dll",CharSet=CharSet.Auto)]
    public extern static uint RasGetErrorString(
     uint uErrorValue,        // error to get string for
     StringBuilder lpszErrorString,  // buffer to hold error string
     [In]int cBufSize           // size, in characters, of buffer
     );

    [DllImport("rasapi32.dll",CharSet=CharSet.Auto)]
    public extern static uint RasConnectionNotification(
     IntPtr hrasconn,  // handle to a RAS connection
     IntPtr hEvent,      // handle to an event object
     RASNOTIFICATION dwFlags       // type of event to receive notifications for
     );

    public static void RasCheck(uint errorCode)
    {
     if(errorCode!=(uint)RasError.SUCCESS)
     { 
      //    throw new RasException(errorCode);
      StringBuilder sb=new StringBuilder(512);
      if(RasAPI.RasGetErrorString(errorCode,sb,sb.Capacity)>0)
       throw new Exception("Unknow RAS exception.");
      //    string ret=sb.ToString();
     }
    }
   }
  [/code]

  Inside class checking internet connection

  [code]
  public class ConnectionState
   {

    private enum ConnectionStateEnum
    {
     //Local system has a valid connection to the Internet, but it might or might not be currently connected.
     ConnectionConfigured = 64,
     //Local system uses a local area network to connect to the Internet.
     ConnectionLan = 2,
     //Local system uses a modem to connect to the Internet.
     ConnectionModem = 1,
     //No longer used.
     ConnectionModemBusy = 8,
     //Local system is in offline mode.
     ConnectionOffline = 32,
     //Local system uses a proxy server to connect to the Internet.
     ConnectionProxy = 4,
     //Local system has RAS installed.
     RasInstalled = 16

    }

    class Win32
    {
     [DllImport("Wininet.dll", CharSet=CharSet.Auto)]
     public static extern int InternetGetConnectedState(out int Flag, int Reserved);
    }

    private static int GetConnectionFlag()
    {
     int Flag;
     Win32.InternetGetConnectedState(out Flag,0);
     return Flag;
    }

    public static bool IsModemConnected()
    {
     return ((GetConnectionFlag() & (int)ConnectionStateEnum.ConnectionModem)==0)
     false : true;
    }
   }
   [/code]
  
  
  den2005

  
  

• Julian Kooiker

  It will be very difficult indeed if you don't know about RAS/VPN and other stuff
  You need to definitely educate yourself by reading MSDN RAS API documentation
  Thanks and good luck.
  
  

• hajik

  Well to start with the remote server should have the thr routing and remote access service installed. It should be configured properly to accept the remote connections. Are you sure you have a properly configured remote access server
  
  

• Breno

  Is that a question or a statement
  
  

• BikerRon

  You can find basic socket client examples here:
  http://msdn.microsoft.com/library/default.asp url=/library/en-us/cpguide/html/cpconsocketcodeexamples.asp
  
  This should get you headed in the right direction.

  
  
  

• Golfnut 1969

  Thanks Durgaprasad Gorti, I am a newbie in this ras, vpn or other remote connection, so do not know what is the wrong or where I like to connect to this remote server programatically, and not configured outside of the application that is what I like to do.
  
  den2005
  

• Dan Stojadinovic

  Thansk for reply, Mike. I like to simualte a VPN connection.
  
  denpsia

  
  
• How to create a Network Connection class that access Remote server?