class1.cs

C#开发教程 由浅入深 配有实例 是初学者的好帮手

using System;

namespace DoubleDispose
{
    public class Thing : IDisposable
    {
        private string name;
        public Thing(string name) { this.name = name; }
        override public string ToString() { return name; }

        ~Thing() 
        { 
            Dispose();
            Console.WriteLine("~Thing()"); 
        }

        private bool AlreadyDisposed = false;

        public void Dispose()
        {
            if (!AlreadyDisposed)
            {
                AlreadyDisposed = true;
                Console.WriteLine("Dispose()");
                GC.SuppressFinalize(this);
            }
        }

        public void Bar()
        {
            if (AlreadyDisposed)
            {
                throw new ObjectDisposedException("Thing");
            }
        }
    }

    public class DoubleDisposeApp
    {
        [STAThread]
        public static void Main(string[] args)
        {
            Thing t = new Thing("Foo");
            Console.WriteLine(t);
            
            t.Dispose();
            t.Dispose();

            GC.Collect();
            GC.WaitForPendingFinalizers();

            try
            {
                t.Bar();
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
        }
    }
}