Delphi Ping 返回通或不通

function pingf (ip :string):string;

var

ReplyStatus:TReplyStatus;

ICMP:TIdIcmpClient;

begin

ICMP:= TIdIcmpClient.Create(nil );

ICMP.ReceiveTimeout := 1000;

ICMP.Host := ip;

try

ICMP.Ping;

ReplyStatus:=icmp.ReplyStatus;

 //Result:=   TStringList.Create;

//if (ReplyStatus.MsRoundTripTime = 0) then

//Result.add('<1')

//else   Result.add(Format('%d',[ReplyStatus.MsRoundTripTime]));

//Result.add(Format('%d',[ ReplyStatus.TimeToLive]));

if (ReplyStatus.MsRoundTripTime = 0) then

  Result := '<1'

else

  Result := Format('%d',[ReplyStatus.MsRoundTripTime]);

except

  Result := '';

end;

ICMP.free;
end;

經本人測試，調用 返回等‘’或'1000'  則爲Ping 不通