.net非托管資源的回收方法

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace MemRelease
{
    class Program
    {
        ~Program()
        {
            // Orders.
        }
        static void Main(string[] args)
        {
        }
    }
}

.method family hidebysig virtual instance void
        Finalize() cil managed
{
  // Code size       14 (0xe)
  .maxstack  1
  .try
  {
    IL_0000:  nop
    IL_0001:  nop
    IL_0002:  leave.s    IL_000c
  }  // end .try
  finally
  {
    IL_0004:  ldarg.0
    IL_0005:  call       instance void [mscorlib]System.Object::Finalize()
    IL_000a:  nop
    IL_000b:  endfinally
  }  // end handler
  IL_000c:  nop
  IL_000d:  ret
} // end of method Program::Finalize

public class Foo: IDisposable
 {
     public void Dispose()
     {
        Dispose(true);
        GC.SuppressFinalize(this);
     }
     protected virtual void Dispose(bool disposing)
     {
        if (!m_disposed)
        {
            if (disposing)
            {
               // Release managed resources
            }
            // Release unmanaged resources
            m_disposed = true;
        }
     }
     ~Foo()
     {
        Dispose(false);
     }
     private bool m_disposed;
 }

namespace 資源回收
{
    class Program
    {
        static void Main(string[] args)
        {
            //使用using對(duì)實(shí)現(xiàn)IDisposable的類(lèi)了進(jìn)行資源管理
/*拿到一個(gè)對(duì)象的時(shí)候，首先判斷這個(gè)對(duì)象是否實(shí)現(xiàn)了IDisposable接口，如果實(shí)現(xiàn)了，最好就用using包裹住這個(gè)對(duì)象，保證這個(gè)對(duì)象用完之后被釋放掉，否則很可能出現(xiàn)資源泄露的問(wèn)題
*/
            using (Telphone t1 = new Telphone())
            {
                t1.Open();
                t1.Speak("hello");
                t1.Bomb();
                //t1.Dispose();//如果在這里調(diào)用了Dispose()方法釋放資源，那么在執(zhí)行t1.Open()方法就出錯(cuò)，電話線已經(jīng)被剪斷了，無(wú)法再打電話了
                t1.Open();
                t1.Speak("I am back!");
            }//代碼執(zhí)行到這里后，就會(huì)調(diào)用Dispose方法來(lái)進(jìn)行資源回收
            Console.ReadKey();
        }
    }
    /// summary>
    /// Telphone類(lèi)實(shí)現(xiàn)了IDisposable接口
    /// /summary>
    class Telphone : IDisposable
    {
        /// summary>
        /// 電話狀態(tài)
        /// /summary>
        private TelphoneState state;
        /// summary>
        /// 打電話
        /// /summary>
        public void Open()
        {
            if (state == TelphoneState.Disposed)
            {
                throw new Exception("電話線已經(jīng)被剪斷，無(wú)法打開(kāi)！");
            }
            state = TelphoneState.Open;
            Console.WriteLine("拿起電話");
        }
        /// summary>
        /// 說(shuō)話
        /// /summary>
        /// param name="s">說(shuō)話內(nèi)容/param>
        public void Speak(string s)
        {
            if (state != TelphoneState.Open)
            {
                throw new Exception("沒(méi)有連接");
            }
            Console.WriteLine(s);
        }
        /// summary>
        /// 掛掉電話
        /// /summary>
        public void Bomb()
        {
            state = TelphoneState.Close;
            Console.WriteLine("掛掉電話");
        }
        IDisposable 成員
    }
    /// summary>
    /// 電話狀態(tài)枚舉
    /// /summary>
    enum TelphoneState
    {
        Open, Close, Disposed
    }
}

public class ResourceHolder : IDisposable
{
      private bool isDispose ＝ false;
      // 顯示調(diào)用的Dispose方法
　 public void Dispose()
      {
           Dispose(true);
          GC.SuppressFinalize(this);
       }
       // 實(shí)際的清除方法
　 protected virtual void Dispose(bool disposing)
      {
            if (!isDisposed)
           {
      　       if (disposing)
　　         {
                      // 這里執(zhí)行清除托管對(duì)象的操作.
                  }
                  // 這里執(zhí)行清除非托管對(duì)象的操作
            }
　        isDisposed=true;
      }
      // 析構(gòu)函數(shù)
      ~ResourceHolder()
      {
            Dispose (false);
      }
}