安全的文件访问方式

public sealed class CallbackOnDispose : IDisposable
    {
        Action callback;
        
        public CallbackOnDispose(Action callback)
        {
            if (callback == null)
                throw new ArgumentNullException("callback");
            this.callback = callback;
        }
        
        public void Dispose()
        {
            Action action = Interlocked.Exchange(ref callback, null);
            if (action != null) {
                action();
                #if DEBUG
                GC.SuppressFinalize(this);
                #endif
            }
        }
        
        #if DEBUG
        ~CallbackOnDispose()
        {
            Debug.Fail("CallbackOnDispose was finalized without being disposed.");
        }
        #endif
    }

using (LockPropertyFile())
 {
     using (FileStream fs = new FileStream(fileName, FileMode.Create, FileAccess.Write, FileShare.None)) 
　　　　{
         ms.WriteTo(fs);
       }
 }

public static IDisposable LockPropertyFile()
        {
            Mutex mutex = new Mutex(false);
            mutex.WaitOne();
            return new CallbackOnDispose(
                delegate {
                    mutex.ReleaseMutex();
                    mutex.Close();
                });
        }