Method extension to get a latitude, longitude Coordinates object of a location string formatted as ISO-6709 Annex H. See https://en.wikipedia.org/wiki/ISO_6709. This is used for example when getting metadata location on Xamarin Android using the MediaMetadataRetriever.

LocationExtensions.cs

using System;
using System.Globalization;
using System.Text.RegularExpressions;

namespace Utilities.Extensions
{
    public static class LocationExtensions
    {
        /// <summary>
        /// Retrieves latitude, longitude coordinates from a ISO-6709 standard string
        /// </summary>
        /// <remarks>
        /// https://en.wikipedia.org/wiki/ISO_6709
        ///
        /// Format:
        ///
        /// ±[latitude]±[longitude]±[height or depth]CRS[CRSDetails]
        ///
        /// where height/depth and CRS are optional, but if height/depth is specified CRS has to be there too.
        ///
        /// Examples:
        ///
        /// Atlantic Ocean +00-025/
        /// France +46+002/
        /// Paris +48.52+002.20/
        /// Eiffel Tower +48.8577+002.295/
        /// Mount Everest +27.5916+086.5640+8850CRSWGS_84/
        /// North Pole +90+000/
        /// Pacific Ocean +00-160/
        /// South Pole -90+000+2800CRSWGS_84/
        /// United States +38-097/
        /// New York City +40.75-074.00/
        /// Statue of Liberty +40.6894-074.0447/
        /// </remarks>
        /// <param name="locationString">Location as ISO-6709 Annex H string to retrieve coordinates</param>
        /// <returns>The coordinate object of the location</returns>
        public static Coordinate? LocationFromISO6709AnnexHString(this String locationString)
        {
            if (string.IsNullOrWhiteSpace(locationString))
            {
                return null;
            }

            var sanitizedLocationString = locationString.TrimEnd('/');

            var pattern = @"(?<latitude>[+-][0-9\.]+)(?<longitude>[+-][0-9\.]+)((?<extrainfo>[+-]\w+)?)";
            var matchCollection = Regex.Matches(sanitizedLocationString, pattern);
            if (matchCollection.Count != 1)
            {
                return null;
            }

            var latString = matchCollection[0].Groups["latitude"]?.Value;
            var lngString = matchCollection[0].Groups["longitude"]?.Value;

            if (!double.TryParse(latString, NumberStyles.Float, CultureInfo.InvariantCulture, out var lat) ||
                !double.TryParse(lngString, NumberStyles.Float, CultureInfo.InvariantCulture, out var lng) ||
                lat == 0 && lng == 0)
            {
                return null;
            }

            return new Coordinate
            {
                Latitude = lat,
                Longitude = lng
            };
        }
    }

    public class Coordinate
    {
        public double Latitude { get; set; }

        public double Longitude { get; set; }
    }
}