如何在此父方法中等待没有 async 修饰符的异步方法? [英] How can I await an async method without an async modifier in this parent method?

问题描述

我有一个想要等待的方法，但我不想造成多米诺骨牌效应，认为任何东西都可以调用此调用方法并等待它.比如我有这个方法:

I have a method that I want to await but I don't want to cause a domino effect thinking anything can call this calling method and await it. For example, I have this method:

public bool Save(string data)
{
   int rowsAffected = await UpdateDataAsync(data);
   return rowsAffected > 0;
}

我打电话:

public Task<int> UpdateDataAsync()
{
  return Task.Run(() =>
  {
    return Data.Update(); //return an integer of rowsAffected
  }
}

这行不通，因为我必须在 Save() 的方法签名中放置async"，然后我不能返回 bool 我必须做它 Task 但我不希望任何人等待 Save() 方法.

This won't work because I have to put "async" in the method signature for Save() and then I can't return bool I have to make it Task<bool> but I don't want anyone awaiting the Save() method.

有没有一种方法可以像 await 一样暂停代码执行，或者以某种方式在没有 async 修饰符的情况下等待此代码?

Is there a way I can suspend the code execution like await or somehow await this code without the async modifier?

推荐答案

如何在父方法中等待没有异步修饰符的异步方法?

How can I await an async method without an async modifier in this parent method?

这有点像问我如何使用 C# 编写应用程序但不依赖任何类型的 .NET 运行时?"

That's kind of like asking "how can I write an application using C# but without taking a dependency on any kind of .NET runtime?"

简短回答:不要那样做.

Short answer: don't do that.

实际上，您在这里所做的是采用一种自然同步的方法(Update)，通过在线程池线程上运行(UpdateDataAsync)使其看起来是异步的)，然后您想要阻塞它以使异步方法看起来是同步的(Save).严重的危险信号.

Really, what you're doing here is taking a naturally-synchronous method (Update), making it appear asynchronous by running it on a thread pool thread (UpdateDataAsync), and then you're wanting to block on it to make the asynchronous method appear synchronous (Save). Serious red flags.

我建议您仔细研究 Stephen Toub 的著名博文 我应该为我的同步方法公开异步包装器 和 我是否应该为我的异步方法公开同步包装器.这两个问题的答案都是否"，尽管 Stephen Toub 解释了如果您确实需要这样做的几种选择.

I recommend you carefully study Stephen Toub's famous pair of blog posts should I expose asynchronous wrappers for my synchronous methods and should I expose synchronous wrappers for my asynchronous methods. The answer to both questions is "no", though Stephen Toub explains several options to do it if you really have to.

真的必须"应该保留给应用程序级别.我假设这些方法(Update、UpdateDataAsync 和 Save)位于应用程序的不同层(例如，数据/数据服务/视图模型)).数据/数据服务层不应进行同步/异步转换.视图模型(特定于应用程序)级别是唯一有理由进行这种转换的级别 - 它只应作为最后的手段.

That "really have to" should be reserved for the application level. I assume these methods (Update, UpdateDataAsync, and Save) are in different layers of the application (e.g., data / data service / view model). The data / data service layers should not be doing synchronous/asynchronous conversions. The view model (application-specific) level is the only one that has an excuse to do that kind of conversion -- and it should only do so as a last resort.

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