MissionPlanner.temp.but_gpsinj_Click C# (CSharp) Method

        private void but_gpsinj_Click(object sender, EventArgs e)
        {
            OpenFileDialog ofd = new OpenFileDialog();
            ofd.Filter = "tlog|*.tlog";
            ofd.ShowDialog();

            SaveFileDialog sfd = new SaveFileDialog();
            sfd.FileName = "output.dat";
            sfd.ShowDialog();

            if (ofd.CheckFileExists)
            {
                using (var st = sfd.OpenFile())
                {
                    using (MAVLinkInterface mine = new MAVLinkInterface(ofd.OpenFile()))
                    {
                        mine.logreadmode = true;

                        while (mine.logplaybackfile.BaseStream.Position < mine.logplaybackfile.BaseStream.Length)
                        {
                            MAVLink.MAVLinkMessage packet = mine.readPacket();

                            if (packet.msgid == (uint)MAVLink.MAVLINK_MSG_ID.GPS_INJECT_DATA)
                            {
                                var item = packet.ToStructure<MAVLink.mavlink_gps_inject_data_t>();
                                st.Write(item.data, 0, item.len);
                            }
                        }
                    }
                }
            }
        }