计算两个点之前的距离

Common/GisHelper.cs

@@ -0,0 +1,29 @@
+namespace LY.App.Common
+{
+    public static class GisHelper
+    {
+        /// <summary>
+        /// 计算两点之间的距离
+        /// </summary>
+        /// <param name="lat1"></param>
+        /// <param name="lon1"></param>
+        /// <param name="lat2"></param>
+        /// <param name="lon2"></param>
+        /// <returns></returns>
+        public static double HaversineDistance(double lat1, double lon1, double lat2, double lon2)
+        {
+            const double R = 6371000.0; // 地球半径（单位：米）
+
+            double dLat = ToRadians(lat2 - lat1);
+            double dLon = ToRadians(lon2 - lon1);
+
+            double a = Math.Sin(dLat / 2) * Math.Sin(dLat / 2) +
+                       Math.Cos(ToRadians(lat1)) * Math.Cos(ToRadians(lat2)) *
+                       Math.Sin(dLon / 2) * Math.Sin(dLon / 2);
+
+            double c = 2 * Math.Atan2(Math.Sqrt(a), Math.Sqrt(1 - a));
+            return R * c;
+        }
+        static double ToRadians(double degrees) => degrees * Math.PI / 180.0;
+    }
+}

Model/Alarm.cs

@@ -37,6 +37,11 @@ namespace LY.App.Model
         public double altitude { get; set; }
         public double home_lat { get; set; }
         public double home_lon { get; set; }
+        /// <summary>
+        /// #距离飞手的距离
+        /// </summary>
+        [SugarColumn(IsIgnore = true)]
+        public double distance { get; set; }
 
         /// <summary>
         /// ,#东向速度

Service/AlarmService.cs

@@ -57,6 +57,7 @@ namespace LY.App.Service
                     item.positionId = deviceinfo.PositionId;
                     item.PostionName = deviceinfo.PositionName;
                     item.Time = input.time;
+                    item.distance = GisHelper.HaversineDistance(item.drone_lat, item.drone_lon, item.app_lat,item.app_lon);
                 }
                 await _db.CopyNew().Insertable(entity).SplitTable().ExecuteReturnSnowflakeIdListAsync();
                 //推送报警信息