对 php 服务器的异步 POST 请求

Question

我正在尝试将一个字符串从我的 C# 应用程序发送到我的 php 服务器（第一次使用异步）。当我尝试写出我对控制台的回复时，我得到了这个：System.Threading.Tasks.Task'1[System.String]

C# 代码

private HttpClient request;
public async Task<string> licenseCheck(HttpClient client, string email){
var payload = new Dictionary<string, string>
{
    { "email", email }
};

var content = new FormUrlEncodedContent(payload);           
var response = await client.PostAsync("https://example.io/checkin.php", content);

return await response.Content.ReadAsStringAsync();
}

request = new HttpClient();
Console.WriteLine(licenseCheck(request,"joe@example.com").ToString());

PHP 代码 - checkin.php

<?php
    $email = trim(strtolower($_POST['email']));
    header('Content-Type: application/x-www-form-urlencoded');
    echo $email;

Answer 1

您在最后一行调用 ToString() 的对象是执行许可证检查的任务。您应该等待对 licenseCheck 的调用，或者使用 Task.Result 属性同步等待任务并在您的请求同步运行时获取结果：

// This allows the runtime to use this thread to do other work while it waits for the license check to finish, when it will then resume running your code
Console.WriteLine(await licenseCheck(request,"joe@example.com"));
// This causes the thread to twiddle its thumbs and wait until the license check finishes, then continue
Console.WriteLine(licenseCheck(request,"joe@example.com").Result);

如果您在 .NET Core 上运行，还可以考虑使用 HttpClientFactory：

https://docs.microsoft.com/en-us/dotnet/standard/microservices-architecture/implement-resilient-applications/use-httpclientfactory-to-implement-resilient-http-requests