WeakTest.cs

using System;

namespace WeakTest
{
	class Program
	{
		static WeakReference<SomeClass> myClass;
		static SomeClass holder;

		static void Main(string[] args)
		{
			CreateClass(ref myClass);
			Console.WriteLine("Hello World!");

			var target = GetTarget(ref myClass);

			target.Tick += Target_Tick;
			holder.TriggerTick();
			holder = null;
			target = null;
			GC.Collect();
			GC.WaitForPendingFinalizers();
			GC.Collect();
			GC.WaitForPendingFinalizers();
			GC.Collect();
			GC.WaitForPendingFinalizers();
			GC.Collect();
			GC.WaitForPendingFinalizers();
			var anotherTarget = GetTarget(ref myClass);
			anotherTarget?.TriggerTick();

			if (anotherTarget is null)
				Console.WriteLine("Disposed");

		}

		private static void Target_Tick(object sender, EventArgs e)
		{
			Console.WriteLine("Ticked");
		}

		static SomeClass GetTarget(ref WeakReference<SomeClass> some)
		{
			some.TryGetTarget(out var target);
			return target;
		}

		static void CreateClass(ref WeakReference<SomeClass> weak)
		{
			holder = new SomeClass();
			weak = new WeakReference<SomeClass>(holder);
		}
	}



	class SomeClass
	{
		public event EventHandler Tick;

		public void TriggerTick() => Tick?.Invoke(this, EventArgs.Empty);
	}
}