IP überprüfen

[Illuminator-23-5]

@Devil: hab ich schon versucht, funzt aber nicht!
@Chakotay1308: thx, hat geholfen!
Ich hab hier mal das ergebnis gepostet:

Delphi-Quellcode:

function IPExists(IP: string): boolean;
var
  hICMP    : DWORD;
  pierWork : PICMP_ECHO_REPLY;
  dwSize   : DWORD;
  UIP: Cardinal;
  a, b, c, d: string;
begin
  a := copy(IP, 1, pos('.', IP)-1); delete(IP, 1, pos('.', IP));
  b := copy(IP, 1, pos('.', IP)-1); delete(IP, 1, pos('.', IP));
  c := copy(IP, 1, pos('.', IP)-1); delete(IP, 1, pos('.', IP));
  d := IP;
  UIP := MAKELONG(MAKEWORD(StrToInt(a), StrToInt(b)),MAKEWORD(StrToInt(c), StrToInt(d)));
  hICMP := IcmpCreateFile;
  if hICMP = INVALID_HANDLE_VALUE then exit;
  try
    dwSize   := SizeOf(ICMP_ECHO_REPLY) + 8;
    pierWork := AllocMem(dwSize);
    try
      if IcmpSendEcho(hICMP,UIP,nil,0,nil,pierWork,dwSize,1000) = 0 then
        result := false
      else
        result := true;
    finally
      FreeMem(pierWork,dwSize);
    end;
  finally
    IcmpCloseHandle(hIcmp);
  end;
end;