MissionPlanner.MAVLinkInterface.GetParam C# (CSharp) Method

        public float GetParam(byte sysid, byte compid, string name = "", short index = -1, bool requireresponce = true)
        {
            if (name == "" && index == -1)
                return 0;

            log.Info("GetParam name: '" + name + "' or index: " + index + " " + sysid + ":" + compid);

            MAVLinkMessage buffer;

            mavlink_param_request_read_t req = new mavlink_param_request_read_t();
            req.target_system = sysid;
            req.target_component = compid;
            req.param_index = index;
            req.param_id = new byte[] {0x0};
            if (index == -1)
            {
                req.param_id = System.Text.ASCIIEncoding.ASCII.GetBytes(name);
            }

            Array.Resize(ref req.param_id, 16);

            generatePacket((byte) MAVLINK_MSG_ID.PARAM_REQUEST_READ, req, sysid, compid);

            if (!requireresponce)
            {
                return 0f;
            }

            giveComport = true;

            DateTime start = DateTime.Now;
            int retrys = 3;

            while (true)
            {
                if (!(start.AddMilliseconds(700) > DateTime.Now))
                {
                    if (retrys > 0)
                    {
                        log.Info("GetParam Retry " + retrys);
                        generatePacket((byte) MAVLINK_MSG_ID.PARAM_REQUEST_READ, req, sysid, compid);
                        start = DateTime.Now;
                        retrys--;
                        continue;
                    }
                    giveComport = false;
                    throw new TimeoutException("Timeout on read - GetParam");
                }

                buffer = readPacket();
                if (buffer.Length > 5)
                {
                    if (buffer.msgid == (byte)MAVLINK_MSG_ID.PARAM_VALUE && buffer.sysid == req.target_system && buffer.compid == req.target_component)
                    {
                        giveComport = false;

                        mavlink_param_value_t par = buffer.ToStructure<mavlink_param_value_t>();

                        string st = System.Text.ASCIIEncoding.ASCII.GetString(par.param_id);

                        int pos = st.IndexOf('\0');

                        if (pos != -1)
                        {
                            st = st.Substring(0, pos);
                        }

                        // not the correct id
                        if (!(par.param_index == index || st == name))
                        {
                            log.ErrorFormat("Wrong Answer {0} - {1} - {2}    --- '{3}' vs '{4}'", par.param_index,
                                ASCIIEncoding.ASCII.GetString(par.param_id), par.param_value,
                                ASCIIEncoding.ASCII.GetString(req.param_id).TrimEnd(), st);
                            continue;
                        }

                        // update table
                        if (MAVlist[sysid,compid].apname == MAV_AUTOPILOT.ARDUPILOTMEGA)
                        {
                            var offset = Marshal.OffsetOf(typeof(mavlink_param_value_t), "param_value");
                            MAVlist[sysid, compid].param[st] = new MAVLinkParam(st, BitConverter.GetBytes(Marshal.ReadInt32(par, offset.ToInt32())), MAV_PARAM_TYPE.REAL32, (MAV_PARAM_TYPE) par.param_type);
                        }
                        else
                        {
                            var offset = Marshal.OffsetOf(typeof(mavlink_param_value_t), "param_value");
                            MAVlist[sysid, compid].param[st] = new MAVLinkParam(st, BitConverter.GetBytes(Marshal.ReadInt32(par, offset.ToInt32())), (MAV_PARAM_TYPE)par.param_type, (MAV_PARAM_TYPE)par.param_type);
                        }

                        MAVlist[sysid, compid].param_types[st] = (MAV_PARAM_TYPE) par.param_type;

                        log.Info(DateTime.Now.Millisecond + " got param " + (par.param_index) + " of " +
                                 (par.param_count) + " name: " + st);

                        return par.param_value;
                    }
                }
            }
        }

        public void doConnect(MAVLinkInterface comPort, string port, string baud)
        {
            bool skipconnectcheck = true;
            comPort.BaseStream = new MissionPlanner.Comms.SerialPort();

            comPort.BaseStream.PortName = port;
            try
            {
                comPort.BaseStream.BaudRate = int.Parse(baud);
            }
            catch { };

            // 记录tlog文件
            try
            {
                Directory.CreateDirectory("D://LogFiles");
                //Directory.CreateDirectory(MainV2.LogDir);
                comPort.logfile =
                    new BufferedStream(
                        File.Open(
                            "D://LogFiles" + Path.DirectorySeparatorChar +
                            DateTime.Now.ToString("yyyy-MM-dd HH-mm-ss") + ".tlog", FileMode.CreateNew,
                            FileAccess.ReadWrite, FileShare.None));

            }
            catch (Exception exp2)
            {
                log.Error(exp2);
                CustomMessageBox.Show(Strings.Failclog);
            } // soft fail


            comPort.Open(false, skipconnectcheck);

            // create a copy
            int[] list = comPort.sysidseen.ToArray();

            comPort.GetParam("MIS_TOTAL");
        }