I am a fairly new programmer and I'm trying to build an app in Xamarin Forms with C#. I am following a tutorial series from YouTube very closely (https://www.youtube.com/playlist?list=PLV916idiqLvcKS1JY3S3jHWx9ELGJ1cJB). I am using Visual Studio 2019, but the tutorial was made with Visual Studio 2017.
I have now finished my login screen and I am trying to move on to the next page in the app. The login screen runs just fine, but as soon as I hit the "Sign in"-button I get the following error:
Newtonsoft.Json.JsonReaderExeption: 'Unexpected character encountered while parsing value: <. Path ", line 0, position 0.'
It seems as though the problem lies within the exchange of data between the app and the database, although - as I'm very new to this - I'm not too sure.
Here are some links to possible solutions I have found so far:
Unexpected character encountered while parsing value,
jsonreaderexception unexpected character encountered,
https://github.com/docusign/docusign-csharp-client/issues/72,
https://www.codeproject.com/Questions/1227147/Unexpected-character-encountered-while-parsing-val,
I have found some more, but I can't seem to be able to apply their solutions to my code either. Speaking of which - here it is:
public RestService()
{
client = new HttpClient();
client.MaxResponseContentBufferSize = 256000;
client.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/x-www-form-urlencoded"));
}
public async Task<Token> Login(User user)
{
var postData = new List<KeyValuePair<string, string>>();
postData.Add(new KeyValuePair<string, string>("grant_type", grant_type));
postData.Add(new KeyValuePair<string, string>("username", user.Username));
postData.Add(new KeyValuePair<string, string>("password", user.Password));
var content = new FormUrlEncodedContent(postData);
var response = await PostResponseLogin<Token>(Constants.LoginUrl, content);
DateTime dt = new DateTime();
dt = DateTime.Today;
response.expire_date = dt.AddSeconds(response.expire_in);
return response;
}
public async Task<T> PostResponseLogin<T>(string weburl, FormUrlEncodedContent content) where T : class
{
var response = await client.PostAsync(weburl, content);
var jsonResult = response.Content.ReadAsStringAsync().Result;
var responseObject = JsonConvert.DeserializeObject<T>(jsonResult);
return responseObject;
}
public async Task<T> PostResponse<T>(string weburl, string jsonstring) where T : class
{
var Token = App.TokenDatabase.GetToken();
string ContentType = "application/json";
client.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", Token.access_token);
try
{
var Result = await client.PostAsync(weburl, new StringContent(jsonstring, Encoding.UTF8, ContentType));
if (Result.StatusCode == System.Net.HttpStatusCode.OK)
{
var JsonResult = Result.Content.ReadAsStringAsync().Result;
try
{
var ContentResp = JsonConvert.DeserializeObject<T>(JsonResult);
return ContentResp;
}
catch { return null; }
}
}
catch { return null; }
return null;
}
public async Task<T> GetResponse<T>(string weburl) where T : class
{
var Token = App.TokenDatabase.GetToken();
client.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", Token.access_token);
try
{
var response = await client.GetAsync(weburl);
if (response.StatusCode == System.Net.HttpStatusCode.OK)
{
var JsonResult = response.Content.ReadAsStringAsync().Result;
try
{
var ContentResp = JsonConvert.DeserializeObject<T>(JsonResult);
return ContentResp;
}
catch { return null; }
}
}
catch { return null; }
return null;
}
This is the only part in the whole project where json is implemented. I don't know if the error could be coming from another part, but I doubt that.
As I mentioned, I am a pretty new programmer, so it is very hard for me to figure out what's wrong or what I could try.
