我有一个存储用户信息（基本信息、地址信息等）的 asp.net mvc 应用程序。现在我需要的是，如果用户 X 搜索其他用户，然后使用他们的地址信息显示所有其他用户 Y 以及 X 和 Y 之间的距离。用户的地址信息包括地址、城市、州、邮政编码和国家。我对地理位置非常陌生，谷歌地图。请建议我“如何计算 asp.net mvc 中两个地址之间的实际距离”。
【问题讨论】：
标签： asp.net asp.net-mvc google-maps geolocation
取自：http://www.geodatasource.com/developers/c-sharp
//:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
//::: :::
//::: This routine calculates the distance between two points (given the :::
//::: latitude/longitude of those points). It is being used to calculate :::
//::: the distance between two locations using GeoDataSource(TM) products :::
//::: :::
//::: Definitions: :::
//::: South latitudes are negative, east longitudes are positive :::
//::: :::
//::: Passed to function: :::
//::: lat1, lon1 = Latitude and Longitude of point 1 (in decimal degrees) :::
//::: lat2, lon2 = Latitude and Longitude of point 2 (in decimal degrees) :::
//::: unit = the unit you desire for results :::
//::: where: 'M' is statute miles :::
//::: 'K' is kilometers (default) :::
//::: 'N' is nautical miles :::
//::: :::
//::: Worldwide cities and other features databases with latitude longitude :::
//::: are available at http://www.geodatasource.com :::
//::: :::
//::: For enquiries, please contact sales@geodatasource.com :::
//::: :::
//::: Official Web site: http://www.geodatasource.com :::
//::: :::
//::: GeoDataSource.com (C) All Rights Reserved 2014 :::
//::: :::
//:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
private double distance(double lat1, double lon1, double lat2, double lon2, char unit) {
double theta = lon1 - lon2;
double dist = Math.Sin(deg2rad(lat1)) * Math.Sin(deg2rad(lat2)) + Math.Cos(deg2rad(lat1)) * Math.Cos(deg2rad(lat2)) * Math.Cos(deg2rad(theta));
dist = Math.Acos(dist);
dist = rad2deg(dist);
dist = dist * 60 * 1.1515;
if (unit == 'K') {
dist = dist * 1.609344;
} else if (unit == 'N') {
dist = dist * 0.8684;
}
return (dist);
}
//:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
//:: This function converts decimal degrees to radians :::
//:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
private double deg2rad(double deg) {
return (deg * Math.PI / 180.0);
}
//:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
//:: This function converts radians to decimal degrees :::
//:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
private double rad2deg(double rad) {
return (rad / Math.PI * 180.0);
}
Console.WriteLine(distance(32.9697, -96.80322, 29.46786, -98.53506, "M"));
Console.WriteLine(distance(32.9697, -96.80322, 29.46786, -98.53506, "K"));
Console.WriteLine(distance(32.9697, -96.80322, 29.46786, -98.53506, "N"));
【讨论】：
首先，您需要使用 Google Map Api 获取地址客户的坐标。 可以这样做： http://dotnet.dzone.com/news/using-google-geocode-get-gps
那么就可以得到2个坐标之间的距离：
var pointA = DbGeography.FromText("POINT (-2.232121 53.477724)", 4326);
var pointB = DbGeography.FromText("POINT (-2.231105 53.478121)", 4326);
var distanceAB = pointA.Distance(pointB); //distanceAB = 80.6382796064941 metres
【讨论】：