[MethodImpl(MethodImplOptions.Synchronized)]

　　在NopCommerce项目的Nop.Core类库中有一个EngineContext类中有一个Initialize方法用到了[MethodImpl(MethodImplOptions.Synchronized)]

 /// <summary>

        /// Initializes a static instance of the Nop factory.

        /// </summary>

        /// <param name="forceRecreate">Creates a new factory instance even though the factory has been previously initialized.</param>

        [MethodImpl(MethodImplOptions.Synchronized)]

        public static IEngine Initialize(bool forceRecreate)

        {

            if (Singleton<IEngine>.Instance == null || forceRecreate)

            {

                var config = ConfigurationManager.GetSection("NopConfig") as NopConfig;

                Singleton<IEngine>.Instance = CreateEngineInstance(config);

                Singleton<IEngine>.Instance.Initialize(config);

            }

            return Singleton<IEngine>.Instance;

        }

 我的理解它和Lock差不多，是解决多线程同步问题的；

 该方法一次只能由一个线程执行。 静态方法锁定类型，而实例方法锁定实例。 在任何实例函数中只能执行一个线程，并且在类的任何静态函数中只能执行一个线程。

• 如果[MethodImplAttribute(MethodImplOptions.Synchronized)]被应用到instance method，相当于对当前实例加锁。
• 如果[MethodImplAttribute(MethodImplOptions.Synchronized)]被应用到static method，相当于当前类型加锁。

实例方法锁定实例

class Program

    {
　　　　//在入口Main方法中，创建SyncHelper对象，通过一个System.Threading.Timer对象实现每隔1s调用该对象的Execute方法：

        static void Main(string[] args)

        {

            SyncHelper sync = new SyncHelper();

            Timer timer = new Timer(delegate

            {

                sync.Execute();

            }, null, 0, 1000);



            Console.ReadKey();

        }

    }



    class SyncHelper

    {

        public void Execute()

        {

            Console.WriteLine("Excute at {0}", DateTime.Now);

            Thread.Sleep(5000);

        }

    }

 class Program

    {

        static void Main(string[] args)

        {

            SyncHelper sync = new SyncHelper();

            Timer timer = new Timer(delegate

            {

                sync.Execute();

            }, null, 0, 1000);



            Console.ReadKey();

        }

    }



    class SyncHelper

    {

        [MethodImpl(MethodImplOptions.Synchronized)]

        public void Execute()

        {

            Console.WriteLine("Excute at {0}", DateTime.Now);

            Thread.Sleep(5000);

        }

    }

静态方法锁定类型

 class Program

    {

        static void Main(string[] args)

        {

            SyncHelper sync = new SyncHelper();

            Timer timer = new Timer(delegate

            {

                SyncHelper.Execute();

            }, null, 0, 1000);



            Console.ReadKey();

        }

    }



    class SyncHelper

    {

        [MethodImpl(MethodImplOptions.Synchronized)]

        public static void Execute()

        {

            Console.WriteLine("Excute at {0}", DateTime.Now);

            Thread.Sleep(5000);

        }

    }

例子：http://www.cnblogs.com/artech/archive/2008/10/17/1313209.html