c# - HostingEnvironment.QueueBackgroundWorkItem 和 HostingEnvironment.RegisterObject 之间的区别

Question

目前我正在使用 HostingEnvironment.RegisterObject 在我的 MVC 5 应用程序中运行我的后台工作。具体来说，我有，

public class BackgroundWorker
{
    /// <summary>
    /// Runs a background task that is registered with the hosting environment
    /// so it is guaranteed to finish executing.
    /// </summary>
    /// <param name="action">The lambda expression to invoke.</param>
    public static void Run(Action action)
    {
        new IISBackgroundTask().DoWork(action);
    }

    /// <summary>
    /// Generic object for completing tasks in a background thread
    /// when the request doesn't need to wait for the results 
    /// in the response.
    /// </summary>
    class IISBackgroundTask : IRegisteredObject
    {
        /// <summary>
        /// Constructs the object and registers itself with the hosting environment.
        /// </summary>
        public IISBackgroundTask()
        {
            HostingEnvironment.RegisterObject(this);
        }

        /// <summary>
        /// Called by IIS, once with <paramref name="immediate"/> set to false
        /// and then again with <paramref name="immediate"/> set to true.
        /// </summary>
        void IRegisteredObject.Stop(bool immediate)
        {
            if (_task.IsCompleted || _task.IsCanceled || _task.IsFaulted || immediate)
            {
                // Task has completed or was asked to stop immediately, 
                // so tell the hosting environment that all work is done.
                HostingEnvironment.UnregisterObject(this);
            }
        }

        /// <summary>
        /// Invokes the <paramref name="action"/> as a Task.
        /// Any exceptions are logged
        /// </summary>
        /// <param name="action">The lambda expression to invoke.</param>
        public void DoWork(Action action)
        {
            try
            {
                _task = Task.Factory.StartNew(action);
            }
            catch (AggregateException ex)
            {
                // Log exceptions
                foreach (var innerEx in ex.InnerExceptions)
                {
                    Logger.Log(innerEx);
                }
            }
            catch (Exception ex)
            {
                Logger.Log(ex);
            }
        }

        private Task _task;
        private static readonly ILogger Logger = Loggers.Logger.Instance;
    }
}

用法，

 BackgroundWorker.Run(() => 
       BackGroundMethod();
 );// run this in a background thread

因此，使用 HostingEnvironment.QueueBackgroundWorkItem 比 HostingEnvironment.RegisterObject 有任何优势

Answer 1

QueueBackgroundWorkItem 实际上只是在幕后对 RegisterObject 的美化调用。它负责将对 Stop 的调用转换为可由异步工作项使用的 CancellationToken，在发生故障时写入事件日志，以及其他一些簿记项.没有什么特别有趣的。您可以使用 Reflector 或 ILSpy 浏览源代码直到 http://referencesource.microsoft.com/使用 4.5.2 源更新。

如果您对自己执行所有簿记的复杂性感到满意，那么您没有理由不继续使用 RegisterObject。新的 API 适用于想要更简单一些的消费者。