I have xamarin.forms app in which I am trying to consume an API. I can get the results but cant deserialize the data. It says "Childern could not be evaluated"
My Json data
{
"success": true,
"user": {
"auth_uuid": "52320",
"current_store": 9,
"permissions": {
"write_notifications": true,
},
"has_accepted_mobile_one_terms": false,
"store": {
"id": 9,
"name": "South Street",
"number": "0009",
}
},
"message": "User Logged In",
"sidebarItems": [
{
"id": 53,
"name": "Notification Center",
}
],
"token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9"
}
My Corresponding C# class
public clas loginData
{
public class Permissions
{
public bool write_notifications { get; set; }
}
public class Store
{
public int id { get; set; }
public string name { get; set; }
public string number { get; set; }
}
public class User
{
public string auth_uuid { get; set; }
public int current_store { get; set; }
public Permissions permissions { get; set; }
public bool has_accepted_mobile_one_terms { get; set; }
public Store store { get; set; }
}
public class SidebarItem
{
public int id { get; set; }
public string name { get; set; }
}
public class RootObject
{
public bool success { get; set; }
public User user { get; set; }
public string message { get; set; }
public List<SidebarItem> sidebarItems { get; set; }
public string token { get; set; }
}
}
My common class for making API call
public class APICall
{
Uri baseAddress = new Uri(CommonValues.BaseURL);
string apiurl;
string postdata;
public ErrorMessageData errorMessage;
public APICall(string apiurl, string postdata)
{
this.apiurl = apiurl;
this.postdata = postdata;
this.loadingIndicator = loadingIndicator;
errorMessage = null;
}
public T APICallResult<T>()
{
try
{
var client = new HttpClient { BaseAddress = baseAddress };
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
var req = new HttpRequestMessage(HttpMethod.Post, apiurl);
req.Content = new StringContent(postdata, Encoding.UTF8, "application/json");
string stringObtained = "";
Task<string> task = Task.Run(async () => await Threading(client, req));
task.Wait();
stringObtained = task.Result;
var jsonObtained = Regex.Unescape(stringObtained);
var resultJSON = '[' + jsonObtained + ']';
T resultObject;//Generic type object
try
{
resultObject = JsonConvert.DeserializeObject<T>(resultJSON);
return resultObject;
}
catch (Exception)
{
List<ErrorMessageData> errorMessages = JsonConvert.DeserializeObject<List<ErrorMessageData>>(resultJSON);
errorMessage = errorMessages[0];
return default(T);
}
}
catch (Exception e)
{
errorMessage = new ErrorMessageData();
errorMessage.Flag = false;
errorMessage.Message = e.Message;
return default(T);
}
}
async Task<string> Threading(HttpClient client, HttpRequestMessage req)
{
var resp = await client.SendAsync(req);
resp.EnsureSuccessStatusCode();
string stringObtained = await resp.Content.ReadAsStringAsync();
return stringObtained;
}
}
How I am making API call
ObservableCollection<loginData> AuthDataObj;
string postdataForAuth = "{\"email\":\"" + "sample#sam.com" + "\",\"password\":\"" + "1234" + "\"}";
NCAPICall callForAuth = new APICall("/auth/login", postdataForAuth, null);
try
{
AuthDataObj = callForAuth.APICallResult<ObservableCollection<loginData>>();
}
catch (Exception ex)
{
await DisplayAlert("Error", ex.Message, "ok");
}
How to solve this issue? Is this something related to mapping of data to my model class?Any help is appriciated.
You need to use RootObject for the deserialization.
Change this line of code
var AuthDataObj = callForAuth.APICallResult<ObservableCollection<RootObject>>();
Related
I am new to Blazor and I am encountering the following issue when trying to post for data with an authentication token : at the time of the API call, an exception is lifted with the message "The JSON value could not be converted to System.Int32. Path: $ | LineNumber: 0 | BytePositionInLine: 1."
Here's the code in my blazor page's code-behind :
public partial class ContactCreate : AuthenticatedPageBase
{
[Inject]
public IContactDataService ContactDataService { get; set; }
[Inject]
public ICountryDataService CountryDataService { get; set; }
public Contact.Post Model { get; set; } = new Contact.Post();
protected string CountryIdString { get; set; } = string.Empty;
protected string TokenString { get; set; } = string.Empty;
public string ErrorMessage { get; set; } = string.Empty;
protected List<Country.ListItem> Countries { get; set; } = new List<Country.ListItem>();
protected async override Task OnInitializedAsync()
{
await base.OnInitializedAsync();
Countries = (await CountryDataService.GetCountryListAsync(Token.Token)).ToList();
TokenString = Token.Token;
}
protected async Task HandleValidSubmit()
{
try
{
Model.CountryId = int.Parse(CountryIdString);
var response = await ContactDataService.PostContactAsync(TokenString, Model);
NavManager.NavigateTo("/contacts");
}
catch(Exception ex)
{
ErrorMessage = ex.Message;
}
}
protected void HandleInvalidSubmit()
{
ErrorMessage = "Le formulaire n'est pas valide. Veuillez réessayer.";
}
}
and here's the relevant code in the data service :
public async Task<int> PostContactAsync(string token, Contact.Post model)
{
var response = await PostAuthenticatedAsync<int>(token, Url, model);
return response;
}
public async Task<T> PostAuthenticatedAsync<T>(string token, string url, object model)
{
var jsonBody = model.ToJson();
var request = new HttpRequestMessage()
{
RequestUri = new Uri(HttpClient.BaseAddress.ToString() + url),
Method = HttpMethod.Post,
Content = jsonBody
};
request.Headers.Authorization = new AuthenticationHeaderValue("bearer", token);
var response = await HttpClient.SendAsync(request);
return await response.FromJson<T>(Options);
}
...and the extension method that serializes the object into json :
public static StringContent ToJson(this object o)
{
return new StringContent(JsonSerializer.Serialize(o), Encoding.UTF8, "application/json");
}
Here's the object model that I'm passing through :
public class Contact
{
public class Post
{
[MaxLength(50)]
public string FirstName { get; set; }
[MaxLength(50)]
public string LastName { get; set; }
[MaxLength(50)]
public string CompanyName { get; set; }
public string AddressLine1 { get; set; }
public string AddressLine2 { get; set; }
[MaxLength(20)]
public string PostCode { get; set; }
[MaxLength(60)]
public string Locality { get; set; }
public int CountryId { get; set; }
}
}
And, finally, here's the API method that I'm trying to reach :
[HttpPost]
public async Task<ActionResult> PostContact(Contact.Post model)
{
try
{
var createdId = await _contactRepository.CreateAsync(model);
return Ok(new { Id = createdId });
}
catch (Exception ex)
{
return BadRequest(new { ex.Message });
}
}
Any idea what is happening or what actual exception lies behind this cryptic error message ?
P.S. : I know that there is a question with that exact exception message but it concerns .NET Core while I'm targeting .NET Standard 2.1. I've read it and it visibly doesn't apply to this case.
You are not returning an int (the Id). You're returning an anonymous object with an int property named Id.
Try
return Ok(createdId);
When I get a json response from HttpClient () and try to deselize, my Xamarin application freezes (UI works, but the code after in class ExecuteGetRequest line 15 does not work). What can it be because of?
No errors.
I call the method of obtaining a list of anime user
ShikimoriMain shikimoriMain = new ShikimoriMain();
var UserInformation = await shikimoriMain.GetUserInformation(Convert.ToInt64(UserID));
var UserAnimeList = await shikimoriMain.GetUserAnimeList(Convert.ToInt64(UserID), 1, 5);
string animeName = UserAnimeList.Anime[0].Anime.Name;
ShikimoriMain.GetUserAnimeList
public async Task<ShikimoriUserAnimeList> GetUserAnimeList(long id, int page, int limit)
{
string[] args = new string[] { ShikimoriCategories.UserID + "/" + id + ShikimoriCategories.UserAnimeList + $"?limit={limit}&page={page}" };
return await ExecuteGetRequest<ShikimoriUserAnimeList>(args);
}
ExecuteGetRequest
public async Task<T> ExecuteGetRequest<T>(string[] args) where T : class
{
T returnedObject;
using (var client = new HttpClient())
{
// client.BaseAddress = new Uri($"{httpApiv1}/{args}");
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Get, httpApiv1 + String.Join("/", args));
request.Headers.TryAddWithoutValidation("User-Agent", "Search Anime");
HttpResponseMessage responseMessage = await client.SendAsync(request);
string json = await responseMessage.Content.ReadAsStringAsync(); // successfully get json
returnedObject = JsonConvert.DeserializeObject<T>(json); // after that the code is not executed
return returnedObject;
}
}
ShikimoriUserAnimeList
public class ShikimoriUserAnimeList
{
[JsonProperty()]
public List<GetAnime> Anime { get; set; }
}
public class GetAnime
{
[JsonProperty("id")]
public int ID { get; set; }
[JsonProperty("status")]
public string Status { get; set; }
[JsonProperty("anime")]
public Anime Anime { get; set; }
}
public class Anime
{
[JsonProperty("id")]
public int ID { get; set; }
[JsonProperty("name")]
public string Name { get; set; }
[JsonProperty("russian")]
public string NameRU { get; set; }
[JsonProperty("image")]
public AnimeImage AnimeImage { get; set; }
[JsonProperty("kind")]
public string King { get; set; }
[JsonProperty("score")]
public string Score { get; set; }
[JsonProperty("status")]
public string Status { get; set; }
[JsonProperty("episodes")]
public int Episodes { get; set; }
}
public class AnimeImage
{
[JsonProperty("original")]
public string Original { get; set; }
[JsonProperty("preview")]
public string Preview { get; set; }
[JsonProperty("x96")]
public string ImageX96 { get; set; }
[JsonProperty("x48")]
public string ImageX48 { get; set; }
}
For the sake of completion:
An error was being thrown but was not visible in the device log. Wrapping the JsonConvert.DeserializeObject<T>(json) in a try catch block helped finding the Exceptionbeing thrown.
try
{
returnedObject = JsonConvert.DeserializeObject<T>(json); // after that the code is not executed
return returnedObject;
}
catch (Exception ex)
{
... (debug and fix the error that occurred)
}
I had same problem, I've realized that using HttpClient async will cause deadlock in winforms or xamarin (however it works well with Asp) and I changed these lines
HttpResponseMessage responseMessage = await client.SendAsync(request);
string json = await responseMessage.Content.ReadAsStringAsync(); // successfully get json
Like these (Make them work synchronous):
HttpResponseMessage responseMessage = client.SendAsync(request).Result;
string json = responseMessage.Content.ReadAsStringAsync().Result; // successfully get json
And change your method as default synchronous
Take a look at Here
I'm running into an error when a nested value is null. If the value is not null everything works as expected. This does not happen if the value is not nested.
The error is:
InvalidCastException: Unable to cast object of type 'System.String' to type 'System.Collections.Generic.IDictionary`2[System.String,System.Object]'.
The error happens when I'm checking response.ErrorException != null on the List Contract
Json returned: Contract administrator is nested and blank error: ends is not nested blank and no error:
"result": [
{
"sys_id": "06dc3133db1747808c47499e0b96192e",
"number": "CNTR001234",
"short_description": "Contract 123",
"u_internal_contact": {
"link": "https://website",
"value": "5b4080490a0a3c9e016cb2a9f4eb57b1"
},
"vendor": {
"link": "https://website",
"value": "b7e7c073c0a801690143e7b7d29eb408"
},
"ends": "",
"payment_amount": "60000",
"u_status": "Active",
"starts": "2018-01-01",
"contract_administrator": ""
}
]
}
Code
public class Results
{
public List<Contract> items { get; set; }
}
public class Contract
{
public string sys_id { get; set; }
public string number { get; set; }
public string short_description { get; set; }
public string ends { get; set; }
public string payment_amount { get; set; }
public string u_status { get; set; }
public string starts { get; set; }
public Vendor vendor { get; set; }
public ContractAdmin contract_administrator { get; set; }
public InternalContact u_internal_contact { get; set; }
}
public class Vendor
{
public string link { get; set; }
public string value { get; set; }
}
public class ContractAdmin
{
public string link { get; set; }
public string value { get; set; }
}
public class InternalContact
{
public string link { get; set; }
public string value { get; set; }
}
public class refResults
{
public List<refName> itemName { get; set; }
}
public class refName
{
public string name { get; set; }
}
class ImportContracts
{
public static void ProcessImport()
{
RestClient contractsRequest = new RestClient(Properties.Settings.Default.RestURL);
contractsRequest.Authenticator = new HttpBasicAuthenticator(Properties.Settings.Default.userName, Properties.Settings.Default.password);
contractsRequest.AddHandler("application/json", new RestSharp.Deserializers.JsonDeserializer());
RestRequest request = new RestRequest();
request.RootElement = "result";
request.OnBeforeDeserialization = resp => { resp.ContentType = "application/json"; };
IRestResponse<List<Contract>> response = contractsRequest.Execute<List<Contract>>(request);
Console.WriteLine(response.Content);
if (response.ErrorException != null)
{
const string message = "Error retrieving response. Check inner details for more info.";
var ex = new ApplicationException(message, response.ErrorException);
throw ex;
}
foreach (Contract contract in response.Data)
{
//Console.WriteLine(contract.sys_id);
string strVendor = GetName(contract.vendor.link.ToString());
string strInternalContact = GetName(contract.u_internal_contact.link.ToString());
string strContractAdmin = GetName(contract.contract_administrator.ToString());
}
}
static public string GetName (string link)
{
RestClient nameRequest = new RestClient(link);
nameRequest.Authenticator = new HttpBasicAuthenticator(Properties.Settings.Default.userName, Properties.Settings.Default.password);
nameRequest.AddHandler("application/json", new RestSharp.Deserializers.JsonDeserializer());
RestRequest requestedName = new RestRequest();
requestedName.RootElement = "result";
requestedName.OnBeforeDeserialization = resp => { resp.ContentType = "application/json"; };
IRestResponse<List<refName>> response = nameRequest.Execute<List<refName>>(requestedName);
if (response.ErrorException != null)
{
const string message = "Error retrieving response. Check inner details for more info.";
var ex = new ApplicationException(message, response.ErrorException);
throw ex;
}
foreach (refName refname in response.Data)
{
return refname.name;
}
return "name not found";
}
}
Any help would be appreciated!
Looking at your JSON, "contract_administrator" is not null, it's an empty string. Your contract requires a ContractAdmin object, so what it's likely doing is attempting to cast an empty string to a ContractAdmin.
If you change "contract_administrator" to be null instead of an empty string, I'm willing to bet that it will parse correctly.
I am connecting to an API, but not having any luck retrieving the data in Json. I have different endpoints to use, but cant seem the any to work. I believe /products should give me the entire list but am having no luck.
class Program
{
static void Main(string[] args)
{
RunAsync().Wait();
}
static async Task RunAsync()
{
using (var client = new HttpClient())
{
//go get the data
string token = "auth token";
client.BaseAddress = new Uri("");
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Add("Authorization", "Bearer " + token);
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
Console.WriteLine("GET");
HttpResponseMessage response = await client.GetAsync("/products/6");
if (response.IsSuccessStatusCode)
{
Console.WriteLine("Connected");
RootObject product = await response.Content.ReadAsAsync<RootObject>();
Console.WriteLine("{0}\t{1}\t{2}\t{3}\t{4}", product.data.id,product.data.name,product.data.sort,product.data.designation_id,product.data.designation_id);
}
else
{
Console.WriteLine("Failed");
Console.WriteLine(response.Headers);
}
}
}
}
The response I am getting in the console on this is:
0
1/1/0001 12:00:00 AM
1/1/0001 12:00:00 AM
Product class:
public class RootObject
{
public Product data { get; set; }
}
public class Product
{
public int id { get; set; }
public object designation_id { get; set; }
public string name { get; set; }
public object alternate_name { get; set; }
public object description { get; set; }
public int sort { get; set; }
public string created_at { get; set; }
public string updated_at { get; set; }
}
The response I get when testing connection with postman is as follows:
{
"data": {
"id": 6,
"designation_id": null,
"name": "Multirate Fork Springs Kit",
"alternate_name": null,
"description": null,
"sort": 0,
"created_at": "2016-06-17 20:47:51",
"updated_at": "2018-05-25 09:40:50"
}
}
nuget Newtonsoft.Json
and you can do something like this:
using Newtonsoft.Json;
in client, using response
Product product = JsonConvert.DeserializeObject<Product>(your response string);
this works really well, as long as your product class has all the right attributes you should be good to go!
I am trying to get a field from the response from the rest services in the Web API we are building. The JSON looks like this:
{
"d": {
"results": [{
"__metadata": {
"id": "Web/Lists(guid'4ddc-41e2-bb44-0f92ad2c0b07')/Items(164)",
"uri": "https://teams.ax.org/sites/js/project/_api/Web/Lists(guid'4ddc-41e2-bb44-0f92ad2c0b07')/Items(164)",
"etag": "\"6\"",
"type": "SP.Data.St_x0020_CdsListItem"
},
"Folder": {
"__deferred": {
"uri": "https://teams.ax.org/sites/js/project/_api/Web/Lists(guid'4ddc-41e2-bb44-0f92ad2c0b07')/Items(164)/Folder"
}
},
"ParentList": {
"__deferred": {
"uri": "https://teams.ax.org/sites/js/project/_api/Web/Lists(guid'4ddc-41e2-bb44-0f92ad2c0b07')/Items(164)/ParentList"
}
},
"PM_x0020_NameId": 220,
"St_x0020_Name": "<div class=\"ExternalClassA14DB0FF86994403B827D91158CF34B0\">KO</div>",
}]
}}
I created these model classes:
public class SharepointDTO
{
public class Metadata
{
[JsonProperty("id")]
public string id { get; set; }
[JsonProperty("uri")]
public string uri { get; set; }
[JsonProperty("etag")]
public string etag { get; set; }
[JsonProperty("type")]
public string type { get; set; }
}
public class Deferred
{
[JsonProperty("uri")]
public string uri { get; set; }
}
public class Folder
{
[JsonProperty("__deferred")]
public Deferred __deferred { get; set; }
}
public class ParentList
{
[JsonProperty("__deferred")]
public Deferred __deferred { get; set; }
}
public class Result
{
[JsonProperty("__metadata")]
public Metadata __metadata { get; set; }
[JsonProperty("Folder")]
public Folder Folder { get; set; }
[JsonProperty("ParentList")]
public ParentList ParentList { get; set; }
[JsonProperty("PM_x0020_NameId")]
public int PM_x0020_NameId { get; set; }
[JsonProperty("St_x0020_Name")]
public string St_x0020_Name { get; set; }
}
public class D
{
[JsonProperty("results")]
public IList<Result> results { get; set; }
}
public class RootObject
{
[JsonProperty("d")]
public D d { get; set; }
}
}
No trying to call the rest service from the Web API and need to get the St_x0020_Name from response and store in a string.
SharepointDTO.RootObject retSharepointobj = await GetfromSharepoint(StNumber);
string StName = retSharepointobj.d.results.St_x0020_Name.ToString();
I am deserializing the JSON in the GetfromSharepoint method like
using (var client_sharePoint = new HttpClient(handler))
{
var response = client_sharePoint.GetAsync(SP_URL).Result;
var responsedata = await response.Content.ReadAsStringAsync();
var returnObj = JsonConvert.DeserializeObject<SharepointDTO.RootObject>(responsedata);
return returnObj;
}
But it throws an error:
'System.Collections.Generic.IList' does not contain a definition for 'St_x0020_Name' and no extension method 'St_x0020_Name' accepting a first argument of type 'System.Collections.Generic.IList' could be found (are you missing a using directive or an assembly reference?)
results is an array, so you have either loop thru like
foreach(var item in retSharepointobj.d.results){
string StName = item.St_x0020_Name.ToString();
}
or get a specific element, for example a first element like:
SharepointDTO.RootObject retSharepointobj = await GetfromSharepoint(StNumber);
string StName = retSharepointobj.d.results[0].St_x0020_Name.ToString();
or you can add an extra check like that
SharepointDTO.RootObject retSharepointobj = await GetfromSharepoint(StNumber);
if(retSharepointobj.d.results.length > 0){
string StName = retSharepointobj.d.results[0].St_x0020_Name.ToString();
}
Shouldn't this line:
string StName = retSharepointobj.d.results.St_x0020_Name.ToString();
Be like this?
string StName = retSharepointobj.d.results.First().St_x0020_Name.ToString();