HttpClient 中的 PostAsync 不向我的 webapi 发送数据

Question

I've created a HttpClient instance to invoke an API with post method.

    using (var client = new HttpClient())
            {
           
                var person = new Stu();
                person.ApplicantId = "48751889-D86E-487B-9508-000EAB65F11F";
                

                var json = JsonConvert.SerializeObject(person);
                var data = new StringContent(json, Encoding.UTF8, "application/json");

                var url = "http://localhost:52085/api/CollegeService/IsCoolegeStudent";
                // var client = new HttpClient();

                var response = await client.PostAsync(url, data);

                string result = response.Content.ReadAsStringAsync().Result;
                Console.WriteLine(result);

            }
    public class Stu
    {
        public string ApplicantId { get; set; }
      
    }

When I check my API out , I receive ApplicantId of my object is Null.

I cant not figure out why ApplicantId is Null.

Finally I've changed my [FromForm] to [FromBody] in my API and it worked correctly but it stuck on this line var response = await client.PostAsync(url, data); and doesn't go on.

the await keyboard make my app stuck ,I've changed it this way var response = await client.PostAsync(url, data).ConfigureAwait(false); but I didn't figure it out why it cause this problem.

Answer 1

If you using FromForm attribute, you should use FormUrlEncodedContent instead of StringContent as content type when you send POST message. If you still want send json - change FromForm at IsCoolegeStudent method to FromBody .