经纬度坐标转换

    /// <summary>
    /// 经纬度与xy坐标转换工具类
    /// </summary>
    public class LatlngXYZConvertHelper
    {
        /// <summary>
        /// 经纬度转xy
        /// </summary>
        /// <param name="lon">需要转换的经度</param>
        /// <param name="lat">需要转换的纬度</param>
        /// <param name="zoom">地图级别</param>
        /// <param name="x">转换后的x坐标</param>
        /// <param name="y">转换后的y坐标</param>
        public static void LatlngToTile(double lon, double lat, int zoom, ref float x, ref float y)
        {
            x = (float)((lon + 180.0) / 360.0 * (1