17monipdb根据IP获得区域

https://www.ipip.net/download.html

https://github.com/17mon/csharp

IpAndPositionHelper

  public class IpAndPositionHelper
    {
        #region Resource
        public static bool EnableFileWatch = false;

        private static int offset;
        private static uint[] index = new uint[];
        private static byte[] dataBuffer;
        private static byte[] indexBuffer;
        private static long lastModifyTime = 0L;
        private static string ipFile;
        private static readonly object @lock = new object();
        #endregion

        #region LoadDat
        public static void Load(string filename)
        {
            ipFile = new FileInfo(filename).FullName;
            Load();
            if (EnableFileWatch)
            {
                Watch();
            }
        }

        private static void Load()
        {
            lock (@lock)
            {
                var file = new FileInfo(ipFile);
                lastModifyTime = file.LastWriteTime.Ticks;
                try
                {
                    dataBuffer = new byte[file.Length];
                    using (var fin = new FileStream(file.FullName, FileMode.Open, FileAccess.Read))
                    {
                        fin.Read(dataBuffer, , dataBuffer.Length);
                    }

                    var indexLength = BytesToLong(dataBuffer[], dataBuffer[], dataBuffer[], dataBuffer[]);
                    indexBuffer = new byte[indexLength];
                    Array.Copy(dataBuffer, , indexBuffer, , indexLength);
                    offset = (int)indexLength;

                    for (var loop = ; loop < ; loop++)
                    {
                        index[loop] = BytesToLong(indexBuffer[loop *  + ], indexBuffer[loop *  + ],
                            indexBuffer[loop *  + ],
                            indexBuffer[loop * ]);
                    }
                }
                catch (Exception ex)
                {
                    throw ex;
                }
            }
        }

        private static uint BytesToLong(byte a, byte b, byte c, byte d)
        {
            return ((uint)a << ) | ((uint)b << ) | ((uint)c << ) | d;
        }

        private static void Watch()
        {
            var file = new FileInfo(ipFile);
            if (file.DirectoryName == null) return;
            var watcher = new FileSystemWatcher(file.DirectoryName, file.Name) { NotifyFilter = NotifyFilters.LastWrite };
            watcher.Changed += (s, e) =>
            {
                var time = File.GetLastWriteTime(ipFile).Ticks;
                if (time > lastModifyTime)
                {
                    Load();
                }
            };
            watcher.EnableRaisingEvents = true;
        }
        #endregion

        #region FindIP
        public static string[] Find(string ip)
        {
            lock (@lock)
            {
                var ips = ip.Split('.');
                var ip_prefix_value = int.Parse(ips[]);
                long ip2long_value = BytesToLong(byte.Parse(ips[]), byte.Parse(ips[]), byte.Parse(ips[]),
                    byte.Parse(ips[]));
                var start = index[ip_prefix_value];
                var max_comp_len = offset - ;
                long index_offset = -;
                var index_length = -;
                byte b = ;
                for (start = start *  + ; start < max_comp_len; start += )
                {
                    if (
                        BytesToLong(indexBuffer[start + ], indexBuffer[start + ], indexBuffer[start + ],
                            indexBuffer[start + ]) >= ip2long_value)
                    {
                        index_offset = BytesToLong(b, indexBuffer[start + ], indexBuffer[start + ],
                            indexBuffer[start + ]);
                        index_length = 0xFF & indexBuffer[start + ];
                        break;
                    }
                }
                var areaBytes = new byte[index_length];
                Array.Copy(dataBuffer, offset + (int)index_offset - , areaBytes, , index_length);
                return Encoding.UTF8.GetString(areaBytes).Split('\t');
            }
        }
        #endregion
    }

        [TestMethod()]
        public void FindTest()
        {
            IpAndPositionHelper.EnableFileWatch = true; // 默认值为：false，如果为true将会检查ip库文件的变化自动reload数据
            string path = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "APP_Data\\tinyipdata_utf8.dat");  //合并目录
            IpAndPositionHelper.Load(path);//加载

            var infos = IpAndPositionHelper.Find("180.169.67.130");//查询

            var result = string.Join("-", infos).TrimEnd('-');      //中国-上海

        }

附IP解析文件：

17monipdb4ecdz.zip