public static async Task<string> GetData(string url, string data)
{
    UriBuilder fullUri = new UriBuilder(url);

    if (!string.IsNullOrEmpty(data))
        fullUri.Query = data;

    HttpClient client = new HttpClient();

    HttpResponseMessage response = await client.PostAsync(new Uri(url), /*expects HttpContent*/);

    response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
    response.EnsureSuccessStatusCode();
    string responseBody = await response.Content.ReadAsStringAsync();

    return responseBody;
}

PostAsync接受另一个需要为HttpContent的参数。

我如何设置一个HttpContent?任何地方都没有适用于Windows Phone 8的文档。

如果我做GetAsync，它工作得很好!但它需要POST，内容为key="bla"， something="yay"

/ /编辑

非常感谢你的回答……这很有效，但仍有一些不确定因素:

    public static async Task<string> GetData(string url, string data)
    {
        data = "test=something";

        HttpClient client = new HttpClient();
        StringContent queryString = new StringContent(data);

        HttpResponseMessage response = await client.PostAsync(new Uri(url), queryString );

        //response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
        response.EnsureSuccessStatusCode();
        string responseBody = await response.Content.ReadAsStringAsync();

        return responseBody;
    }

我假设数据“test=something”会在api端作为post数据“test”，显然它不是。在另一个问题上，我可能需要通过post数据发布整个对象/数组，所以我认为json将是最好的。关于我如何获得post数据有什么想法吗?

也许是这样的:

class SomeSubData
{
    public string line1 { get; set; }
    public string line2 { get; set; }
}

class PostData
{
    public string test { get; set; }
    public SomeSubData lines { get; set; }
}

PostData data = new PostData { 
    test = "something",
    lines = new SomeSubData {
        line1 = "a line",
        line2 = "a second line"
    }
}
StringContent queryString = new StringContent(data); // But obviously that won't work