C# Lesson 24 : Understanding Event-Driven Programming

Learn how events are utilized in the .NET Framework Class Library specific to WPF and ASP.NET Web Forms applications. In these examples, we see how C# is generated by the IDE to "wire up" a user action or application event to the code that handles that event.

WPF

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WPFEvents
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            MyButton.Click += MyButton_Click;
            MyButton.Click += MyButton_IClickedThis;
        }

        void MyButton_Click(object sender, RoutedEventArgs e)
        {
            //throw new NotImplementedException();
            MyLabel.Content = "Hello World!";
        }

        void MyButton_IClickedThis(object sender, RoutedEventArgs e)
        {
            //throw new NotImplementedException();
            MyLabel.Content = "Hello World again!";
        }

    }
}


ASP.NET

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace ASPNETEvents
{
    public partial class Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            MyButton.Click += MyButton_Click;
        }

        void MyButton_Click(object sender, EventArgs e)
        {
            //throw new NotImplementedException();
            MyLabel.Text = "Hello world!";
        }

 
    }
}

Source : MS Virtual Academy