Erkennen ob der Computer mit einem Netzwerk verbunden ist

[Delphi Star]

Wie kann man erkennen ob, eine der Netzerkkarten des Systems mit einem Netzwerk verbunden ist :?:

[Delphi Star]

Kann mit denn keiner helfen :?:
Es musst doch irgendwie möglich sein zu erkennen, ob in einer der Netzwerkkarten ein Netwerkkabel steckt, oder ob in keiner eins ist.

[Luckie]

Nein, geht nicht: http://www.marian-aldenhoevel.de/dojo/internet.html

[Sharky]

Zitat:

Zitat von Delphi Star

... ob in einer der Netzwerkkarten ein Netwerkkabel steckt, ....

Hmmm... Seit WIN 2000 wird einem dies ja vom OS angezeigt. Jetzt muss man nur rausfinden ob es auch eine API-Funktion gibt um den Status der Netzwerkberbindung in erfahrung zu bringen.

[kalmi01]

Hi,

folgende Sourcen sind nicht von mir, weiss auch nicht mehr woher ich sie habe und getstet sind erst recht nicht, aber vielleicht helfen sie trotzdem.

Delphi-Quellcode:

function IsNetworkConnected: Boolean; 
begin 
  if GetSystemMetrics(SM_NETWORK) and $01 = $01 then 
  begin 
    Result := True; 
  end 
  else 
  begin 
    Result := False; 
  end; 
end;

Delphi-Quellcode:

unit NetworkFunctions; 

interface 

uses 
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, 
  Dialogs, StdCtrls, WinInet, WinSock; 

type 
  PNetResourceArray = ^TNetResourceArray; 
  TNetResourceArray = array[0..100] of TNetResource; 

type 
  IPAddr = DWORD; 

  PICMP_ECHO_REPLY = ^ICMP_ECHO_REPLY; 
  ICMP_ECHO_REPLY = packed record 
    Address       : ULONG; 
    Status        : ULONG; 
    RoundTripTime : ULONG; 
    DataSize      : WORD; 
    Reserved      : WORD; 
    Data          : Pointer; 
  end; 

  PIP_OPTION_INFORMATION = ^IP_OPTION_INFORMATION; 
  IP_OPTION_INFORMATION = packed record 
    Ttl         : byte; 
    Tos         : byte; 
    Flags       : byte; 
    OptionsSize : byte; 
    OptionsData : Pointer; 
  end; 

procedure GetComputerList(List: TStrings); 
function InternetAvailable:Boolean;                                 // Only DFÜ / RAS 
function Ping(IP:string; TimeOut:Cardinal) : Boolean;                 // TimeOut ~1000 
function GetNetworkName(IPAddr: string): string; 
function GetIp(const HostName: string): string; 

implementation 

function IcmpCreateFile : DWORD; stdcall; external 'icmp.dll'; 
function IcmpCloseHandle(const IcmpHandle : DWORD) : longbool; stdcall; external 'icmp.dll'; 
function IcmpSendEcho(const IcmpHandle : DWORD;const DestinationAddress : IPAddr;const RequestData : Pointer;const RequestSize : WORD;const RequestOptions : PIP_OPTION_INFORMATION;const ReplyBuffer : Pointer;const ReplySize : DWORD;const TimeOut : DWORD) : DWORD; stdcall; external 'icmp.dll' 

function GetNetworkName(IPAddr: string): string; 
  var SockAddrIn: TSockAddrIn; 
      HostEnt: PHostEnt; 
      WSAData: TWSAData; 
begin 
  WSAStartup($101, WSAData); 
  SockAddrIn.sin_addr.s_addr := inet_addr(PChar(IPAddr)); 
  HostEnt:= GetHostByAddr(@SockAddrIn.sin_addr.S_addr, 4, AF_INET); 
  if HostEnt <> nil then 
    Result := StrPas(Hostent^.h_name) 
  else 
    Result := ''; 
end; 

function GetIp(const HostName: string): string; 
  type 
    TaPInAddr = array[0..10] of PInAddr; 
    PaPInAddr = ^TaPInAddr; 
  var 
    phe: PHostEnt; 
    pptr: PaPInAddr; 
    i: Integer; 
    GInitData: TWSAData; 
begin 
  WSAStartup($101, GInitData); 
  Result := ''; 
  phe := GetHostByName(PChar(HostName)); 
  if phe = nil then Exit; 
  pPtr := PaPInAddr(phe^.h_addr_list); 
  i := 0; 
  while pPtr^[i] <> nil do begin 
    Result := inet_ntoa(pptr^[i]^); 
    Inc(i); 
  end; 
  WSACleanup; 

end; 

function Ping(IP:string; TimeOut:Cardinal):Boolean; 
  var hICMP                           : DWORD; 
      pierWork                        : PICMP_ECHO_REPLY; 
      dwSize                          : DWORD; 
      Class1,Class2,Class3,Class4     : String; 
      i,j                             : Byte; 
begin 
  Result:=False; 
  j:=1; 
  for i:=1 to Length(IP) do begin 
    if IP[i]<>'.' then begin 
      case j of 
        1: Class1:=Class1+IP[i]; 
        2: Class2:=Class2+IP[i]; 
        3: Class3:=Class3+IP[i]; 
        4: Class4:=Class4+IP[i]; 
      end; 
    end else 
      Inc(j); 
  end; 
  hICMP := IcmpCreateFile; 
  if hICMP = INVALID_HANDLE_VALUE then exit; 
  try 
    dwSize   := SizeOf(ICMP_ECHO_REPLY)+8; 
    pierWork := AllocMem(dwSize); 
    try 
      if IcmpSendEcho(hICMP,MAKELONG(MAKEWORD(StrToInt(Class1), StrToInt(Class2)),MAKEWORD(StrToInt(Class3), StrToInt(Class4))),nil,0,nil,pierWork,dwSize,TimeOut) = 0 then 
        Result:=False 
      else 
        Result:=True; 
    finally 
      FreeMem(pierWork,dwSize); 
    end; 
  finally 
    IcmpCloseHandle(hIcmp); 
  end; 
end; 

  // Nur für DFÜ / RAS 
function InternetAvailable:Boolean; 
begin 
  Result := InternetCheckConnection(nil, 0, 0); 
end; 

function CreateNetResourceList(ResourceType: DWord; 
                              NetResource: PNetResource; 
                              out Entries: DWord; 
                              out List: PNetResourceArray): Boolean; 
var 
  EnumHandle: THandle; 
  BufSize: DWord; 
  Res: DWord; 
begin 
  Result := False; 
  List := Nil; 
  Entries := 0; 
  if WNetOpenEnum(RESOURCE_GLOBALNET,ResourceType,0,NetResource,EnumHandle) = NO_ERROR then begin 
    try 
      BufSize := $4000;  // 16 kByte  
      GetMem(List, BufSize);  
      try 
        repeat 
          Entries := DWord(-1);  
          FillChar(List^, BufSize, 0); 
          Res := WNetEnumResource(EnumHandle, Entries, List, BufSize);  
          if Res = ERROR_MORE_DATA then begin  
            ReAllocMem(List, BufSize); 
          end;  
        until Res <> ERROR_MORE_DATA; 

        Result := Res = NO_ERROR; 
        if not Result then begin 
          FreeMem(List);  
          List := Nil;  
          Entries := 0; 
        end;  
      except 
        FreeMem(List);  
        raise; 
      end;  
    finally  
      WNetCloseEnum(EnumHandle); 
    end;  
  end; 
end; 

procedure GetComputerList(List: TStrings); 
  procedure ScanLevel(ResourceType, DisplayType: DWord; NetResource: PNetResource); 
  var 
    Entries: DWord; 
    NetResourceList: PNetResourceArray; 
    i: Integer; 
  begin 
    if CreateNetResourceList(ResourceType, NetResource, Entries, NetResourceList) then try 
      for i := 0 to Integer(Entries) - 1 do begin 
        if (DisplayType = RESOURCEDISPLAYTYPE_GENERIC) or 
          (NetResourceList[i].dwDisplayType = DisplayType) then begin 
          List.AddObject(NetResourceList[i].lpRemoteName, 
                        Pointer(NetResourceList[i].dwDisplayType)); 
        end; 
        if (NetResourceList[i].dwUsage and RESOURCEUSAGE_CONTAINER) <> 0 then 
          ScanLevel(RESOURCETYPE_DISK, RESOURCEDISPLAYTYPE_SERVER,@NetResourceList[i]); 
      end; 
    finally 
      FreeMem(NetResourceList); 
    end; 
  end; 
begin 
  ScanLevel(RESOURCETYPE_DISK, RESOURCEDISPLAYTYPE_SERVER, Nil); 
end; 

end.