///// <summary>
///// test
///// </summary>
///// <param name="args"></param>
//public void main()
//{
// double lat = 39.90403;
// double lon = 116.407526; //需要查询经纬度，目前指向的是BeiJing
// string hash = Geohash.Encode(lat, lon);
// int geohashLen = 6;
// /*获取中心点的geohash*/
// String geohash = hash.Substring(0, geohashLen);
// /*获取所有的矩形geohash， 一共是九个 ，包含中心点,打印顺序请参考图2*/
// String[] result = Geohash.getGeoHashExpand(geohash);
//}
/// <summary>
/// 生成查询 geohash 九个格子 的sql语句
/// </summary>
/// <param name="geohashLen">长度，5位是十平方千米（长 宽 3.3km），6位是3.3平方千米(长 宽 1点多km)</param>
/// <param name="lat">纬度</param>
/// <param name="lng">经度</param>
/// <param name="geoHashField">数据库存geohash的字段名</param>
/// <returns></returns>
public static String getsqlGeoHash(int geohashLen, string Latitude, string Longitude, string geoHashField)
{
double lat = double.Parse(Latitude);
double lon = double.Parse(Longitude);
string hash = Geohash.Encode(lat, lon);
/*获取中心点的geohash*/
String geohash = hash.Substring(0, geohashLen);
/*获取所有的矩形geohash， 一共是九个 ，包含中心点,打印顺序请参方法*/
String[] result = Geohash.getGeoHashExpand(geohash);
string where = "( ";
for (int i = 0; i < 9; i++)
{
if (i == 0)
{
where += geoHashField + " like '" + result[i] + "%' ";
}
else
{
where += " or " + geoHashField + " like '" + result[i] + "%' ";
}
}
where += ") ";
return(where);
}
private static void Main(string[] args)
{
const double testLat = 40.7571397;
const double testLong = -73.9891705;
const int precision = 13;
// Calculate hash with full precision
string hash = Geohash.Encode(testLat, testLong, precision);
// Print out the hash for a range of precision
for (int i = 1; i <= precision; i++)
{
Debug.WriteLine("{0}, {1} {2}: {3}", testLat, testLong, i, Geohash.Encode(testLat, testLong, i));
}
// Print neighbours
Debug.WriteLine("{0} \t: {1}", "T", Geohash.CalculateAdjacent(hash, Geohash.Direction.Top));
Debug.WriteLine("{0} \t: {1}", "L", Geohash.CalculateAdjacent(hash, Geohash.Direction.Left));
Debug.WriteLine("{0} \t: {1}", "R", Geohash.CalculateAdjacent(hash, Geohash.Direction.Right));
Debug.WriteLine("{0} \t: {1}", "B", Geohash.CalculateAdjacent(hash, Geohash.Direction.Bottom));
}
