How to create MessageBox Show  in C#.NET  

Double click on this button . will be create cs page and write below this code

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Windows.Forms;

namespace PricticeOne

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        private void button1_Click(object sender, EventArgs e)

            MyClass.ShowMessage(20);

        }

After create a class page and write below this code

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace PricticeOne

{

    class MyClass

    {

        enum Names:byte

        {

            Adm = 1,

            jon = 2,

            miki=3

        }

        string Name;

        public MyClass(string name)

        {

            Name = name;

        }

         string name()

        {

            return Name;

        }

         Names myname = Names.Adm;

        public static void ShowMessage(string message)

         {

             System.Windows.Forms.MessageBox.Show(message);

         }

        public static void ShowMessage(int message)

        {

            System.Windows.Forms.MessageBox.Show(message.ToString());

        }

    }

}

How to Create FileDialog in C#.NET

At first take a form . Than take  a button in toolber . Last step double click on the button create a new page , write this code on this page . done  . Run your page .