function PingAlive(const AHost: string; const ATimeout: Cardinal = 1000):
  boolean;
var
  IdIcmpClient: TIdIcmpClient;
begin
  try
    IdIcmpClient := TIdIcmpClient.Create(nil);
    IdIcmpClient.ReceiveTimeout := ATimeout; //設定回應的等候時間
    IdIcmpClient.Host := AHost;
    Result := true;
    try
      IdIcmpClient.Ping;
    except
      Result := false;
    end;
  finally
    FreeAndNil(IdIcmpClient);
  end;
end;    function CheckServerAlive(const AHost: string; const APort: integer): boolean;
var
  IdTCPClient: TIdTCPClient;
begin
  Result := false;      if not PingAlive(AHost) then
    Exit;      try
    IdTCPClient := TIdTCPClient.Create(nil);
    IdTCPClient.Host := AHost;
    IdTCPClient.Port := APort;        try
      IdTCPClient.Connect;
      Result := true;
    except
      Result := false;
    end;
    IdTCPClient.Disconnect;
  finally
    FreeAndNil(IdTCPClient);
  end;
end;