在。net 4.6中测试。它还可以避免死锁。

对于返回Task的异步方法。

Task DoSomeWork();
Task.Run(async () => await DoSomeWork()).Wait();

对于返回Task<T>的异步方法

Task<T> GetSomeValue();
var result = Task.Run(() => GetSomeValue()).Result;

编辑:

如果调用者在线程池线程中运行(或者调用者也在任务中)，在某些情况下仍然可能导致死锁。

下面是我发现的一个变通方法，适用于所有情况(包括被停职的调度员)。这不是我的代码，我仍在努力完全理解它，但它确实有效。

它可以被调用使用:

customerList = AsyncHelpers.RunSync<List<Customer>>(() => GetCustomers());

代码从这里开始

public static class AsyncHelpers
{
    /// <summary>
    /// Execute's an async Task<T> method which has a void return value synchronously
    /// </summary>
    /// <param name="task">Task<T> method to execute</param>
    public static void RunSync(Func<Task> task)
    {
        var oldContext = SynchronizationContext.Current;
        var synch = new ExclusiveSynchronizationContext();
        SynchronizationContext.SetSynchronizationContext(synch);
        synch.Post(async _ =>
        {
            try
            {
                await task();
            }
            catch (Exception e)
            {
                synch.InnerException = e;
                throw;
            }
            finally
            {
                synch.EndMessageLoop();
            }
        }, null);
        synch.BeginMessageLoop();

        SynchronizationContext.SetSynchronizationContext(oldContext);
    }

    /// <summary>
    /// Execute's an async Task<T> method which has a T return type synchronously
    /// </summary>
    /// <typeparam name="T">Return Type</typeparam>
    /// <param name="task">Task<T> method to execute</param>
    /// <returns></returns>
    public static T RunSync<T>(Func<Task<T>> task)
    {
        var oldContext = SynchronizationContext.Current;
        var synch = new ExclusiveSynchronizationContext();
        SynchronizationContext.SetSynchronizationContext(synch);
        T ret = default(T);
        synch.Post(async _ =>
        {
            try
            {
                ret = await task();
            }
            catch (Exception e)
            {
                synch.InnerException = e;
                throw;
            }
            finally
            {
                synch.EndMessageLoop();
            }
        }, null);
        synch.BeginMessageLoop();
        SynchronizationContext.SetSynchronizationContext(oldContext);
        return ret;
    }

    private class ExclusiveSynchronizationContext : SynchronizationContext
    {
        private bool done;
        public Exception InnerException { get; set; }
        readonly AutoResetEvent workItemsWaiting = new AutoResetEvent(false);
        readonly Queue<Tuple<SendOrPostCallback, object>> items =
            new Queue<Tuple<SendOrPostCallback, object>>();

        public override void Send(SendOrPostCallback d, object state)
        {
            throw new NotSupportedException("We cannot send to our same thread");
        }

        public override void Post(SendOrPostCallback d, object state)
        {
            lock (items)
            {
                items.Enqueue(Tuple.Create(d, state));
            }
            workItemsWaiting.Set();
        }

        public void EndMessageLoop()
        {
            Post(_ => done = true, null);
        }

        public void BeginMessageLoop()
        {
            while (!done)
            {
                Tuple<SendOrPostCallback, object> task = null;
                lock (items)
                {
                    if (items.Count > 0)
                    {
                        task = items.Dequeue();
                    }
                }
                if (task != null)
                {
                    task.Item1(task.Item2);
                    if (InnerException != null) // the method threw an exeption
                    {
                        throw new AggregateException("AsyncHelpers.Run method threw an exception.", InnerException);
                    }
                }
                else
                {
                    workItemsWaiting.WaitOne();
                }
            }
        }

        public override SynchronizationContext CreateCopy()
        {
            return this;
        }
    }
}

我遇到过几次，主要是在单元测试或windows服务开发中。目前我一直在使用这个功能:

        var runSync = Task.Factory.StartNew(new Func<Task>(async () =>
        {
            Trace.WriteLine("Task runSync Start");
            await TaskEx.Delay(2000); // Simulates a method that returns a task and
                                      // inside it is possible that there
                                      // async keywords or anothers tasks
            Trace.WriteLine("Task runSync Completed");
        })).Unwrap();
        Trace.WriteLine("Before runSync Wait");
        runSync.Wait();
        Trace.WriteLine("After runSync Waited");

这很简单，很容易，我没有任何问题。

在代码中，第一个等待任务执行，但是你还没有启动它，所以它会无限期地等待。试试这个:

Task<Customer> task = GetCustomers();
task.RunSynchronously();

编辑:

你说你得到了一个异常。请发布更多细节，包括堆栈跟踪。 Mono包含以下测试用例:

[Test]
public void ExecuteSynchronouslyTest ()
{
        var val = 0;
        Task t = new Task (() => { Thread.Sleep (100); val = 1; });
        t.RunSynchronously ();

        Assert.AreEqual (1, val);
}

检查一下这对你是否有效。如果没有，尽管不太可能，你可能会有一些奇怪的Async CTP构建。如果它可以工作，您可能需要检查编译器到底生成了什么，以及Task实例化与这个示例有什么不同。

编辑# 2:

我检查了反射器，你所描述的异常发生时m_action为空。这有点奇怪，但我不是异步CTP的专家。正如我所说，你应该反编译你的代码，看看Task是如何被实例化的，不管它的m_action是如何为空的。

使用下面的代码剪辑

Task.WaitAll(Task.Run(async () => await service.myAsyncMethod()));

wp8:

包装:

Task GetCustomersSynchronously()
{
    Task t = new Task(async () =>
    {
        myCustomers = await GetCustomers();
    }
    t.RunSynchronously();
}

叫它:

GetCustomersSynchronously();