java - android-查找离我当前位置最近的位置

Question

我的数据库中有一些 GPS 坐标。

我获取了当前位置，但我不知道如何找到离我最近的位置以及我与这些点之间的距离。

你能帮我找到最近的位置以及我与这些点之间的距离吗？

Answer 1

使用此方法求两点之间的距离http://www.geodatasource.com/developers/java

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);
    }

    private double deg2rad(double deg) {
      return (deg * Math.PI / 180.0);
    }

    system.println(distance(32.9697, -96.80322, 29.46786, -98.53506, "M") + " Miles\n");
    system.println(distance(32.9697, -96.80322, 29.46786, -98.53506, "K") + " Kilometers\n");
    system.println(distance(32.9697, -96.80322, 29.46786, -98.53506, "N") + " Nautical Miles\n");