/// <summary>
    ///  计算坐标距离
    /// </summary>
    /// <param name="lngA">坐标A经度</param>
    /// <param name="latA">坐标A纬度</param>
    /// <param name="lngB">坐标B经度</param>
    /// <param name="latB">坐标B纬度</param>
    /// <returns></returns>
    private double AccountDistance(double lngA, double latA, double lngB, double latB)
    {
        double DistanceLng = 102834.74258026089786013677476285;
        double DistanceLat = 111712.69150641055729984301412873;
        double LngAbs = Math.Abs((lngA - lngB) * DistanceLng);
        double LatAbs = Math.Abs((latA - latB) * DistanceLat);
        return Math.Sqrt((LatAbs * LatAbs + LngAbs * LngAbs));
    }