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 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.