NullReference Exception在Z61AA5CCE7B7B72EC74B1DFA878AA2BDB56Z.Z6450242531912981C3683CAE888A32A66Z上致电postAsync。

Question

When I try to call, it throws me this error: System.NullReferenceException Message=Object reference not set to an instance of an object. Is there something wrong with the code? Need Help!

public Command RegisterUser
    {
        get
        {
            return new Command(async () =>
            {
                UserInfo user = new UserInfo();
                //try
                //{
                    user.UserId = 99;
                    user.LoginId = "aaaa";
                    user.FirstName = "aaa";
                    user.SecondName = "ddd";
                    user.ThirdName = "dd";
                    user.DOB = DateTime.Now.Date;
                    user.PhoneNo = "332323";
                    user.Email = "aa.aa.com";
                    user.Password = "aaaa";

                    string jsonData = JsonConvert.SerializeObject(user);
                    string url = "http://192.168.18.22:44368/api/User";
                    HttpClient client1 = new HttpClient();
                    client1.MaxResponseContentBufferSize = int.MaxValue;
                    StringContent content = new StringContent(jsonData, Encoding.UTF8, "application/json");
                    HttpResponseMessage response1 = await client1.PostAsync(url, content);
                    string result = "";
                    if (response1 != null)
                        result = await response1.Content.ReadAsStringAsync();

                //}

                //catch (Exception ex)
                //{
                //    string eee = "";
                //}

            });
        }
    }

Answer 1

You maybe should check content on null as well as response1, seems like here is the problem. More info about stack trace can help also

 if (response1 != null) result = await response1.Content?.ReadAsStringAsync();