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Categories / Delphi / LAN Web TCP
 

Being checked you this connected the internet

Title: Being checked you this connected the internet? Question: how to know the application opened a door for internet. Answer: interface uses Windows, SysUtils, Registry, WinSock, WinInet; type TConnectionType = (ctNone, ctProxy, ctDialup); function ConnectedToInternet : TConnectionType; function RasConnectionCount : Integer; implementation //For RasConnectionCount ======================= const cERROR_BUFFER_TOO_SMALL = 603; cRAS_MaxEntryName = 256; cRAS_MaxDeviceName = 128; cRAS_MaxDeviceType = 16; type ERasError = class(Exception); HRASConn = DWord; PRASConn = ^TRASConn; TRASConn = record dwSize: DWORD; rasConn: HRASConn; szEntryName: Array[0..cRAS_MaxEntryName] Of Char; szDeviceType : Array[0..cRAS_MaxDeviceType] Of Char; szDeviceName : Array [0..cRAS_MaxDeviceName] of char; end; TRasEnumConnections = function (RASConn: PrasConn; { buffer to receive Connections data } var BufSize: DWord; { size in bytes of buffer } var Connections: DWord { number of Connections written to buffer } ): LongInt; stdcall; //End RasConnectionCount ======================= function ConnectedToInternet: TConnectionType; var Reg : TRegistry; bUseProxy : Boolean; UseProxy : LongWord; begin Result := ctNone; Reg := TRegistry.Create; with REG do try try RootKey := HKEY_CURRENT_USER; if OpenKey('\Software\Microsoft\Windows\CurrentVersion\Internet settings',False) then begin //I just try to read it, and trap an exception if GetDataType('ProxyEnable') = rdBinary then ReadBinaryData('ProxyEnable', UseProxy, SizeOf(LongWord) ) else begin bUseProxy := ReadBool('ProxyEnable'); if bUseProxy then UseProxy := 1 else UseProxy := 0; end; if (UseProxy 0) and ( ReadString('ProxyServer') '' ) then Result := ctProxy; end; except //Obviously not connected through a proxy end; finally Free; end; //We can check RasConnectionCount even if dialup networking is not installed //simply because it will return 0 if the DLL is not found. if Result = ctNone then begin if RasConnectionCount 0 then Result := ctDialup; end; end; function RasConnectionCount : Integer; var RasDLL : HInst; Conns : Array[1..4] of TRasConn; RasEnums : TRasEnumConnections; BufSize : DWord; NumConns : DWord; RasResult : Longint; begin Result := 0; //Load the RAS DLL RasDLL := LoadLibrary('rasapi32.dll'); if RasDLL = 0 then exit; try RasEnums := GetProcAddress(RasDLL,'RasEnumConnectionsA'); if @RasEnums = nil then raise ERasError.Create('RasEnumConnectionsA not found in rasapi32.dll'); Conns[1].dwSize := Sizeof (Conns[1]); BufSize := SizeOf(Conns); RasResult := RasEnums(@Conns, BufSize, NumConns); If (RasResult = 0) or (Result = cERROR_BUFFER_TOO_SMALL) then Result := NumConns; finally FreeLibrary(RasDLL); end; end;