问题
I am using LocationManager to get the values of Latitude and Longitude of a user. These values are updated regularly to a database.
Now, i want to find out the distance between two users basing on the stored Latitude and Longitude values. I want to display a message when distance between two users is less than (say 100 meters). Can anyone please guide me with a tutorial or some sample code of how to achieve it.
回答1:
You can have a look at the Location class. You can set the longitude and latitude and there is a distanceTo method that you can use
回答2:
Ou pode utilizar este metodo que eu desenvolvi... Or you can use this method I developed...
public static Double distance(latitudeA, latitudeB, longitudeA, longitudeB) {
double radius = 3958.75;
double dlat = ToRadians(Double.parseDouble(String.valueOf(latitudeB))
- Double.parseDouble(String.valueOf(latitudeA)));
double dlon = ToRadians(Double.parseDouble(String.valueOf(longitudeB))
- Double.parseDouble(String.valueOf(longitudeA)));
double a = Math.sin(dlat / 2)
* Math.sin(dlat / 2)
+ Math.cos(ToRadians(Double.parseDouble(String.valueOf(latitudeA))))
* Math.cos(ToRadians(Double.parseDouble(String.valueOf(latitudeB)))) * Math.sin(dlon / 2)
* Math.sin(dlon / 2);
double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
Double d = radius * c;
double meterConversion = 1609.00;
return d * meterConversion;
}
private static double ToRadians(double degrees) {
double radians = degrees * 3.1415926535897932385 / 180;
return radians;
}
来源:https://stackoverflow.com/questions/4544972/how-to-calculate-distance-using-coordinates-from-locationmanager