C# 在WebClient.UploadStringTaskAsync之后获取响应cookies

在重载WebClient类之后

public class CustomWebClient : WebClient
{
    public CustomWebClient()
    {
        Cookies = new CookieCollection();
        CookieContainer = new CookieContainer();
    }

    public CookieContainer CookieContainer { get; }
    public CookieCollection Cookies { get; private set; }

    protected override WebRequest GetWebRequest(Uri address)
    {
        var request = (HttpWebRequest)base.GetWebRequest(address);
        
        request.CookieContainer = CookieContainer;

        return request;
    }

    protected override WebResponse GetWebResponse(WebRequest request)
    {
        var response = (HttpWebResponse)base.GetWebResponse(request);
        
        Cookies = response.Cookies;

        return response;
    }
}

我可以使用client.UploadString获取cookies

public string Test()
{
    using (var client = new CustomWebClient())
    {
        //...

        client.UploadString("example.com", "json");

        return client.Cookies
    }
}

但是如何使用client.UploadStringTaskAsync获取cookies

public async Task<string> Test()
{
    using (var client = new CustomWebClient())
    {
        //...

        await client.UploadStringTaskAsync("example.com", "json");

        return client.Cookies // There are no cookies!
    }
}

公共异步任务测试（）
{
使用（var client=new CustomWebClient（））
{
//...
等待client.UploadStringTaskAsync（“example.com”、“json”）；
返回客户端。Cookies//没有Cookies！
}
}

你觉得需要更多的解释吗？
因为stackoverflow警告：

---

看起来你的帖子大部分都是代码；请添加更多详细信息。

我通过覆盖GetWebResponse（WebRequest请求，IAsyncResult结果）解决了这个问题

public class CustomWebClient : WebClient
{
    public CustomWebClient()
    {
        Cookies = new CookieCollection();
        CookieContainer = new CookieContainer();
    }

    public CookieContainer CookieContainer { get; }
    public CookieCollection Cookies { get; private set; }

    protected override WebRequest GetWebRequest(Uri address)
    {
        var request = (HttpWebRequest)base.GetWebRequest(address);
        
        request.CookieContainer = CookieContainer;

        return request;
    }

    protected override WebResponse GetWebResponse(WebRequest request)
    {
        var response = (HttpWebResponse)base.GetWebResponse(request);
        
        Cookies = response.Cookies;

        return response;
    }

    protected override WebResponse GetWebResponse(WebRequest request, IAsyncResult result)
    {
        var response = (HttpWebResponse)base.GetWebResponse(request);

        Cookies = response.Cookies;

        return response;
    }
}