イベントハンドラーの中でさらにイベントを起こすと、再帰的に呼び出されてしまう

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

using System.Threading;



namespace HogeApp

{

    public partial class Form1 : Form

    {

        private Hoge hoge = new Hoge();

        private System.Timers.Timer timer = new System.Timers.Timer();



        public Form1()

        {

            InitializeComponent();

            hoge.HogeHandler += new HogeEventHandler(hoge_HogeHandler);

            timer.Elapsed += new System.Timers.ElapsedEventHandler(timer_Elapsed);

        }



        private void hoge_HogeHandler(object sender, HogeEventArgs e)

        {

            Console.WriteLine("hoge_HogeHandler at " + DateTime.Now);

            Thread.Sleep(1 * 1000);

            hoge.foo();

        }



        private void button1_Click(object sender, EventArgs e)

        {

            hoge.foo();

        }



        private void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)

        {

            Console.WriteLine("timer_Elapsed at " + DateTime.Now);

            hoge.foo();

        }



        private void button2_Click(object sender, EventArgs e)

        {

            timer.AutoReset = false;

            // SynchronizingObject プロパティーを設定すると、タイマーが発火するスレッドを選べる。

            //timer.SynchronizingObject = this;

            timer.Interval = 3 * 1000;



            timer.Start();

        }

    }



    class HogeEventArgs : EventArgs

    {

        public HogeEventArgs()

        {

        }

    }



    delegate void HogeEventHandler(object sender, HogeEventArgs e);



    class Hoge

    {

        public event HogeEventHandler HogeHandler;

        // イベントキュー

        private List<HogeEventArgs> eas = new List<HogeEventArgs>();



        public Hoge()

        {

            Application.Idle += new EventHandler(Application_Idle);

        }



        private void Application_Idle(object sender, EventArgs e)

        {

            Console.WriteLine("Application_Idle at " + DateTime.Now);

            // イベントキューが空になるまで繰り返す。

            while (eas.Count > 0)

            //if (eas.Count > 0)

            {

                HogeEventArgs ea = eas[0];

                eas.RemoveAt(0);

                if (HogeHandler != null)

                {

                    HogeHandler(this, ea);

                }

            }

        }



        public void foo()

        {

            eas.Add(new HogeEventArgs());

            // Application.RaiseIdle(new EventArgs());

        }

    }

}