/// <summary>
/// 计算两个经纬度之间的直接距离
/// </summary>
public static double GetDistance(Geography start, Geography end)
{
double s = Math.Acos(Math.Cos(start.LatRadians) * Math.Cos(end.LatRadians) * Math.Cos(start.LngRadians - end.LngRadians) + Math.Sin(start.LatRadians) * Math.Sin(end.LatRadians));
if (double.IsNaN(s)) return 0;
s = s * EARTH_RADIUS;
s = Math.Round(s * 10000) / 10000;
return s;
}
/// <summary>
/// 计算两个经纬度之间的直接距离
/// </summary>
public static double GetDistance(Geography start, Geography end)
{
double s = Math.Acos(Math.Cos(start.LatRadians) * Math.Cos(end.LatRadians) * Math.Cos(start.LngRadians - end.LngRadians) + Math.Sin(start.LatRadians) * Math.Sin(end.LatRadians));
if (double.IsNaN(s))
{
return(0);
}
s = s * EARTH_RADIUS;
s = Math.Round(s * 10000) / 10000;
return(s);
}
/// <summary>
/// 以一个经纬度为中心计算出四个顶点
/// </summary>
/// <param name="point">半径(米)</param>
/// <param name="distance">半径(米)</param>
/// <returns></returns>
public static Range GetCoordinates(Geography point, double distance)
{
double dlng = Math.Abs(ToDegrees(2 * Math.Asin(Math.Sin(distance / (2 * EARTH_RADIUS)) / Math.Cos(point.Latitude))));
double dlat = Math.Abs(ToDegrees(distance / EARTH_RADIUS));
return new Range
{
Left = Math.Round(point.Longitude - dlng, 6),
Right = Math.Round(point.Longitude + dlng, 6),
Top = Math.Round(point.Latitude + dlat, 6),
Bottom = Math.Round(point.Latitude - dlat, 6)
};
}
/// <summary>
/// 以一个经纬度为中心计算出四个顶点
/// </summary>
/// <param name="point">半径(米)</param>
/// <param name="distance">半径(米)</param>
/// <returns></returns>
public static Range GetCoordinates(Geography point, double distance)
{
double dlng = Math.Abs(ToDegrees(2 * Math.Asin(Math.Sin(distance / (2 * EARTH_RADIUS)) / Math.Cos(point.Latitude))));
double dlat = Math.Abs(ToDegrees(distance / EARTH_RADIUS));
return(new Range
{
Left = Math.Round(point.Longitude - dlng, 6),
Right = Math.Round(point.Longitude + dlng, 6),
Top = Math.Round(point.Latitude + dlat, 6),
Bottom = Math.Round(point.Latitude - dlat, 6)
});
}
