Tag: Lambda expressions

Here is a code for custom events in C#. Note the 3.5 style code that involves Lambda expressions and Anonymous types.

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

namespace ConsoleApplication1
{
    using TestNamespace;

    class Program
    {
        static void Main(string[] args)
        {
            Test t = new Test();

            t.TestStarted += (object sender, Test.TestStartedEventArgs e) =>
                {
                    Console.WriteLine("First event handler");
                    Console.WriteLine(sender.ToString());
                    Console.WriteLine(e.ToString());
                };

            t.TestStarted += (object sender, Test.TestStartedEventArgs e) =>
                {
                    Console.WriteLine("Second event handler @ " + e.StartedTime);
                };

            t.DoTest();

            Console.ReadLine();
        }
    }
}

namespace TestNamespace
{
    class Test
    {
        public delegate void TestStartedHandler(object sender, TestStartedEventArgs e);

        public event TestStartedHandler TestStarted;

        public class TestStartedEventArgs : EventArgs
        {
            public string StartedTime { get; set; }
        }

        public void DoTest()
        {
            if (this.TestStarted != null)
            {
                this.TestStarted(this,
                    new TestStartedEventArgs
                    {
                        StartedTime = DateTime.Now.ToString()
                    });
            }
        }
    }
}