在Xamarin上使用AntiForgeryToken访问Aspnet 5.0中的WebAPI

我正在尝试访问一个使用ValidateAntiForgeryToken的WebAPI。我的WebAPI方法如下（一个简单的方法），它位于一个用户控制器中（仅用于测试）：\n

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Test(String field)
{
    String result = String.Empty;
    if (ModelState.IsValid)
    {
        HtmlSanitizer sanitizer = new HtmlSanitizer();
        try
        {
            result = sanitizer.Sanitize(field);
        }
        catch (Exception ex)
        {
            result = ex.Message;
            throw;
        }
    }
    return Json(result);
}

\n通过Ajax，我可以轻松访问它：\n

$.ajax({
    url: '/User/Test',
    type: "POST",
    contentType: "application/x-www-form-urlencoded",
    data: {
        field: self.textField(),
        __RequestVerificationToken: $("input[name='__RequestVerificationToken']").val(),
    },
    success: function(e) {
        self.textField(e)
        self.divField(e);
    },
    error: function(e) {
        console.log(e.error());
    },
});

\n但是，到目前为止，我无法使用Xamarin中的HttpClient访问此WebAPI。这是我的代码：\n

private async void DoTestWebApi()
{
    try
    {
        HttpClient clientPage = new HttpClient()
        {
            BaseAddress = new Uri("https://localhost:44356/user")
        };
        var pageWithToken = await clientPage.GetAsync(clientPage.BaseAddress);
        String verificationToken = GetVerificationToken(await pageWithToken.Content.ReadAsStringAsync());
        HttpClient client = new HttpClient()
        {
            BaseAddress = new Uri("https://localhost:44356/user/test/")
        };
        HttpRequestMessage message = new HttpRequestMessage()
        {
            RequestUri = new Uri("https://localhost:44356/user/test/"),
            Method = HttpMethod.Post
        };
        message.Headers.Add("__RequestVerificationToken", verificationToken);
        String field = "teste";
        StringContent content = new StringContent("__RequestVerificationToken=" + verificationToken + ",field=test", Encoding.UTF8, "application/x-www-form-urlencoded");
        var response2 = await client.SendAsync(message);
        if (response2.IsSuccessStatusCode)
        {
            var t = response2.Content.ReadAsStringAsync();
            if (true)
            {
                // just to check if t has value
            }
        }
    }
    catch (Exception ex)
    {
        Console.WriteLine(ex.Message);
        throw;
    }
}

\n老实说，我不知道还能做什么来在消息中传递我的防伪标记。它在ajax中完美运行，我将其传递给数据内容，但在Xamarin中不起作用。\n所有的代码都在同一台本地主机上执行。如果我删除[ValidateAntiForgeryToken]，它可以工作。\n我错过了什么吗？\n编辑：\n好吧，现在我正在使用cookie发送，但它没有再次命中方法。\n这是我的更新：\n

HttpClient clientPage = new HttpClient()
{
    BaseAddress = new Uri("https://localhost:44356/user")
};
var pageWithToken = await clientPage.GetAsync(clientPage.BaseAddress);
String verificationToken = GetVerificationToken(await pageWithToken.Content.ReadAsStringAsync());
List> cookiesInfo = new List>();
foreach (var item in pageWithToken.Headers)
{
    cookiesInfo.Add(new KeyValuePair(item.Key, item.Value.ToString()));
}
cookiesInfo.Add(new KeyValuePair("field", "value"));
cookiesInfo.Add(new KeyValuePair("__RequestVerificationToken", verificationToken));
CookieContainer cookieContainer = new CookieContainer();
using (var handler = new HttpClientHandler() { CookieContainer = cookieContainer })
{
    using (var client = new HttpClient(handler) { BaseAddress = new Uri("https://localhost:44356/user") })
    {
        var content = new FormUrlEncodedContent(cookiesInfo);
        cookieContainer.Add(client.BaseAddress, new Cookie("__RequestVerificationToken", verificationToken));
        foreach (var item in cookiesInfo)
        {
            cookieContainer.Add(client.BaseAddress, new Cookie(item.Key, item.Value));
        }
        var result = client.PostAsync(new Uri("https://localhost:44356/user/test"), content).Result;
        result.EnsureSuccessStatusCode();
    }
};

\n这让我抓狂...好吧，测试是在本地主机上，但很快这个应用程序将在Azure上运行，这是一个先决条件...\n编辑：GetVerificationToken方法：\n

private string GetVerificationToken(String verificationToken)
{
    if (verificationToken != null && verificationToken.Length > 0)
    {
        verificationToken = verificationToken.Substring(verificationToken.IndexOf("__RequestVerificationToken"));
        verificationToken = verificationToken.Substring(verificationToken.IndexOf("value=\"") + 7);
        verificationToken = verificationToken.Substring(0, verificationToken.IndexOf("\""));
    }
    return verificationToken;
}