.Net HttpClient form-data格式请求

             var multipartFormDataContent = new MultipartFormDataContent();
             multipartFormDataContent.Add(new StringContent("admin"), "UserName");
             multipartFormDataContent.Add(new StringContent(""), "Password");
             var client = _clientFactory.CreateClient();
             var response = await client.PostAsync("http://localhost", multipartFormDataContent);
             if (response.IsSuccessStatusCode)
             {
                 //do
             }