如何使用HttpClient发布数据？

我从Nuget获得了这个HttpClient。

当我想获取数据时，可以这样：

var response = await httpClient.GetAsync(url);
var data = await response.Content.ReadAsStringAsync();

但是问题是我不知道如何发布数据？我必须发送一个发布请求，并在其中发送以下值：comment="hello world"和questionId = 1。我不知道这些可以是类的属性。

更新我不知道如何将这些值添加到HttpContent后方法需要它。httClient.Post(string, HttpContent);

您需要使用：

await client.PostAsync(uri, content);

像这样：

var comment = "hello world";
var questionId = 1;

var formContent = new FormUrlEncodedContent(new[]
{
    new KeyValuePair<string, string>("comment", comment), 
    new KeyValuePair<string, string>("questionId", questionId) 
});

var myHttpClient = new HttpClient();
var response = await myHttpClient.PostAsync(uri.ToString(), formContent);

如果您需要在发布后获得回复，则应使用：

var stringContent = await response.Content.ReadAsStringAsync();

希望能帮助到你 ;）

尝试使用此：

using (var handler = new HttpClientHandler() { CookieContainer = new CookieContainer() })
{
    using (var client = new HttpClient(handler) { BaseAddress = new Uri("site.com") })
    {
        //add parameters on request
        var body = new List<KeyValuePair<string, string>>
        {
            new KeyValuePair<string, string>("test", "test"),
            new KeyValuePair<string, string>("test1", "test1")
        };

        HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, "site.com");

        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/x-www-form-urlencoded; charset=UTF-8"));
        client.DefaultRequestHeaders.Add("Upgrade-Insecure-Requests", "1");
        client.DefaultRequestHeaders.Add("X-Requested-With", "XMLHttpRequest");
        client.DefaultRequestHeaders.Add("X-MicrosoftAjax", "Delta=true");
        //client.DefaultRequestHeaders.Add("Accept", "*/*");

        client.Timeout = TimeSpan.FromMilliseconds(10000);

        var res = await client.PostAsync("", new FormUrlEncodedContent(body));

        if (res.IsSuccessStatusCode)
        {
            var exec = await res.Content.ReadAsStringAsync();
            Console.WriteLine(exec);
        }                    
    }
}

使用UploadStringAsync方法：

WebClient webClient = new WebClient();
webClient.UploadStringCompleted += (s, e) =>
{
    if (e.Error != null)
    {
        //handle your error here
    }
    else
    {
        //post was successful, so do what you need to do here
    }
};

webClient.UploadStringAsync(new Uri(yourUri), UriKind.Absolute), "POST", yourParameters);