Visual Studio 2012 中的 HTTPClient POST

Question

我想将数据发布到 REST API，但它没有创建正确的请求：

using (var client = new HttpClient())

{

client.DefaultRequestHeaders.Add("Accept", "text/csv");

HttpResponseMessage response = null;

string baseUrl = ServiceUrl + "/api/v25/upload/test";

Dictionary<string, string> parameters = new Dictionary<string, string>();

parameters.Add("field1", "value1");

parameters.Add("field2", "value2");

MultipartFormDataContent form = new MultipartFormDataContent();

HttpContent content = new StringContent("long text...");

content.Headers.ContentType = new MediaTypeHeaderValue("text/csv");

HttpContent fields = new FormUrlEncodedContent(parameters);

form.Add(content, "message");

form.Add(fields);

response = client.PostAsync(baseUrl, form).Result;

var message = response.Content.ReadAsStringAsync().Result;

}

它使这个 URL：

POST /api/v25/upload/test HTTP/1.1

这将是正确的地址：

POST /api/v25/upload/test?field1=value1&field2=value2 HTTP/1.1

请问代码错误在哪里？