异步/等待和同步代码常见吗？ [英] Async/Await and synchronous code common?

问题描述

我创建了一个包含每个方法的同步和异步版本的库。每种方法都有很多共同的代码，但方法中的差异是存在await关键字和方法签名。



我想做的是有一种方法，所以我不必在两种方法之间复制代码。我只是不确定如何做到这一点。我已经读过，包装任何一个版本和从另一个版本调用是一个坏主意。



以下是我所谈论的一个例子。我有两种GetDirectoryListing方法 - GetDirectoryListing和GetDirectoryListingAsync。我希望有办法消除重复的代码。



谢谢。

I have created a library that has both synchronous and asynchronous versions of each method. Each method has a lot of common code, but the differences within the methods are the presence of the await keyword and the method signature.

What I would like to do is have a way so that I don't have to replicate code between the two methods. I am just not sure as to how to do this. I have read that wrapping either version and calling from the other one is a bad idea.

Below is an example of what I am talking about. I have two methods for GetDirectoryListing - GetDirectoryListing and GetDirectoryListingAsync. I'd like to have a way to eliminate the duplicated code.

Thanks.

public static List<string> GetDirectoryListing(FTPLoginCredentials credentials)
        {
            List<string> directoryListing = new List<string>();
                FtpWebRequest ftpReq = CreateFtpWebRequest(credentials, WebRequestMethods.Ftp.ListDirectory);

                using (FtpWebResponse ftpResp = (FtpWebResponse)ftpReq.GetResponse())
                {
                    string html;
                    using (StreamReader sr = new StreamReader(ftpResp.GetResponseStream(), System.Text.Encoding.UTF8))
                        html = sr.ReadToEnd();
                    directoryListing.AddRange(html.Split(new string[] { Environment.NewLine, "\r" }, StringSplitOptions.RemoveEmptyEntries));
                }
                return directoryListing;
            }
        }

public static async Task<List<string>> GetDirectoryListingAsync(FTPLoginCredentials credentials)
        {
            List<string> directoryListing = new List<string>();
            FtpWebRequest ftpReq = CreateFtpWebRequest(credentials, WebRequestMethods.Ftp.ListDirectory);

                using (FtpWebResponse ftpResp = (FtpWebResponse)await ftpReq.GetResponseAsync())
                {
                    string html;
                    using (StreamReader sr = new StreamReader(ftpResp.GetResponseStream(), System.Text.Encoding.UTF8))
                        html = await sr.ReadToEndAsync().ConfigureAwait(false);
                    directoryListing.AddRange(html.Split(new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries));
                }
                return directoryListing;
        }

推荐答案

简单的方法是将阻塞代码实现为异步代码的瘦包装器。< br $> b $ b

The easy way out is to have the blocking code implemented as a thin wrapper around the async code.

public static async Task<list<string>> GetDirectoryListingAsync(FTPLoginCredentials credentials)
{
    List<string> directoryListing = new List<string>();
    FtpWebRequest ftpReq = CreateFtpWebRequest(credentials, WebRequestMethods.Ftp.ListDirectory);

        using (FtpWebResponse ftpResp = (FtpWebResponse)await ftpReq.GetResponseAsync())
        {
            string html;
            using (StreamReader sr = new StreamReader(ftpResp.GetResponseStream(), System.Text.Encoding.UTF8))
                html = await sr.ReadToEndAsync().ConfigureAwait(false);
            directoryListing.AddRange(html.Split(new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries));
        }
        return directoryListing;
}

public static List<string> GetDirectoryListing(FTPLoginCredentials credentials)
{
    Task<list<string>> task = GetDirectoryListingAsync(credentials);
    task.Wait();
    return task.Result;
}

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