Alexander's questions

此示例取自 dotnet/fsharp 文档，由于以下原因，它已过时 - “此构造已弃用。WebRequest、HttpWebRequest、ServicePoint 和 WebClient 已过时。请改用 HttpClient。” https://learn.microsoft.com/en-us/dotnet/fsharp/language-reference/async-expressions

这个例子使用 HttpClient 看起来怎么样？

需要说明的是，我是 Web 开发的新手，但我确实了解异步表达式是什么，只是在将示例转换为使用 HttpClient 时遇到了麻烦。

open System.Net
open Microsoft.FSharp.Control.WebExtensions

let urlList = [ "Microsoft.com", "http://www.microsoft.com/"
                "MSDN", "http://msdn.microsoft.com/"
                "Bing", "http://www.bing.com"
            ]

let fetchAsync(name, url:string) =
    async {
        try
            let uri = new System.Uri(url)
            let webClient = new WebClient()
            let! html = webClient.AsyncDownloadString(uri)
            printfn "Read %d characters for %s" html.Length name
        with
            | ex -> printfn "%s" (ex.Message);
    }

let runAll() =
    urlList
    |> Seq.map fetchAsync
    |> Async.Parallel
    |> Async.RunSynchronously
    |> ignore

runAll()