using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp5
{
    class Program
    {
        static void Main(string[] args)
        {
            double lat = 38.89861;
            Console.WriteLine("{0} > {1}", lat, ConvertDoubleToDegreeAngleLat(lat));
            double lon = -76.96222;
            Console.WriteLine("{0} > {1}", lon, ConvertDoubleToDegreeAngleLon(lon));

            double degrees;
            double minutes;
            double seconds;
            string dir;

            Console.WriteLine();

            degrees = 38;
            minutes = 53;
            seconds = 55.0;
            dir = "N";
            Console.WriteLine("{0} {1} {2} {3} > {4:f5}", degrees, minutes, seconds, dir, ConvertDegreeAngleToDouble(degrees, minutes, seconds, dir));
            degrees = 76;
            minutes = 57;
            seconds = 44.0;
            dir = "W";
            Console.WriteLine("{0} {1} {2} {3} > {4:f5}", degrees, minutes, seconds, dir, ConvertDegreeAngleToDouble(degrees, minutes, seconds, dir));
        }

        public static string ConvertDoubleToDegreeAngleLat(double doubleDegrees)
        {
            string dir = (doubleDegrees >= 0 ? "N" : "S");
            return ConvertDoubleToDegreeAngle(doubleDegrees, dir);
        }
        public static string ConvertDoubleToDegreeAngleLon(double doubleDegrees)
        {
            string dir = (doubleDegrees >= 0 ? "E" : "W");
            return ConvertDoubleToDegreeAngle(doubleDegrees, dir);
        }
        public static string ConvertDoubleToDegreeAngle(double doubleDegrees, string dir)
        {
            doubleDegrees = Math.Abs(doubleDegrees);
            double latMinPart = ((doubleDegrees - Math.Truncate(doubleDegrees) / 1) * 60);
            double latSecPart = ((latMinPart - Math.Truncate(latMinPart) / 1) * 60);

            double degrees = Math.Truncate(doubleDegrees);
            double minutes = Math.Truncate(latMinPart);
            double seconds = latSecPart;

            return string.Format("{0} {1} {2} {3}", degrees, minutes, seconds.ToString("#.0"), dir);
        }

        public static double ConvertDegreeAngleToDouble(double degrees, double minutes, double seconds, string dir)
        {
            //Decimal degrees = 
            //   whole number of degrees, 
            //   plus minutes divided by 60, 
            //   plus seconds divided by 3600

            int multiplier = (dir == "S" || dir == "W") ? -1 : 1; //handle south and west
            return (degrees + (minutes / 60) + (seconds / 3600)) * multiplier;
        }
    }
}

• Geographic coordinate conversion
• Convert latitude and longitude to degree [duplicate]
• CONVERT LATITUDE/LONGITUDE BETWEEN DECIMAL AND DEGREES/MINUTES/SECONDS IN C#
• Convert Degrees/Minutes/Seconds to Decimal Coordinates

1. เพิ่ม Reference ชื่อ System.Configuration
2. กำหนด config ในไฟล์ App.config
3. สร้างคลาส LogClass
4. Program.cs

1. เพิ่ม Reference ชื่อ System.Configuration
2. กำหนด path ที่ใช้เก็บ Log
3. สร้างคลาส LogClass
4. Program.cs

1. การใช้โอเปอเรเตอร์ + และ +=
2. การใช้ string interpolation
3. การใช้ StringBuilder
4. การใช้ string
5. การใช้ LINQ