[Share Code] Tìm hiểu về NameSpace + Exception trong C#, Lập trình C#, Lập Trình C Sharp

#Program.cs

using System;
using Models.Data;
using Models.Test;

namespace Lession4
{
    class Program
    {
        static void Main(string[] args)
        {
            TestNamespace();
            //try {
            //    //block code => xu ly
            //    Console.WriteLine("x = ");
            //    int x = int.Parse(Console.ReadLine());
            //    Console.WriteLine("y = ");
            //    int y = int.Parse(Console.ReadLine());

            //    float r = x / y;
            //    Console.WriteLine("r = " + r);

            //    //Tuyet doi ko de giai phong tai nguyen duoi try.
            //} catch(ArithmeticException e) {
            //    Console.WriteLine(e.ToString());
            //} finally {
            //    // block code => giai phong tai nguyen
            //}
        }

        static void TestNamespace() {
            float r = Calculator.Plus(2.2f, 5.6f);

            Console.WriteLine("Ket qua: " + r);

            Console.WriteLine("Hello World!");

            Models.Data.Abc.ShowMessage("ABCBBC");

            BBB bB = new BBB();
            bB.Test();

            Models.Test.Abc abc = Models.Test.Abc.Instance;
            abc.ShowMessage("ABC");

            Models.Test.Abc.Instance.ShowMessage("Hello");
        }
    }
}

#Calculator.cs

using System;
namespace Models.Data
{
    public class Calculator
    {
        public static float Plus(float a, float b) {
            return a + b;
        }
    }

    public class Abc
    {
        public static void ShowMessage(string msg)
        {
            Console.WriteLine("Data >> Test >> " + msg);
        }
    }
}

//Test = Hieu ve trien khai namespace + folder.
namespace Models.Test {
    public class Abc
    {
        static Abc _instance = null;

        private Abc() {}

        public static Abc Instance {
            get {
                if(_instance == null) {
                    _instance = new Abc();
                }
                return _instance;
            }
        }

        public void ShowMessage(string msg) {
            Console.WriteLine("Hello >> " + msg);
        }
    }

    public class BBB {
        public void Test() {
            Console.WriteLine("test....");
        }
    }
}