I'm coming today for a little problem where I'm stuck.
I'm making a c# xamarin app and this one receives messages (JSON) from my server.
The thing is, this message contains 2 fixes variables (String Descrption, Int StatusId).
However, a third value is put in this message. This value can be either an object or a range of object. It means that my class can be the two following possibilities:
Case 1 -> I got an object as Result
public class Result
{
public string name { get; set; }
}
public class RootObject
{
public string Description { get; set; }
public Result Results { get; set; }
public int StatusId { get; set; }
}
Case 2 -> I got a list of results as List<Result>
public class Result
{
public string name { get; set; }
}
public class RootObject
{
public string Description { get; set; }
public List<Result> Results { get; set; }
public int StatusId { get; set; }
}
Of course, it's all time a Result object which is get, however, it can be either alone or such as a list.
How can I deserialize this object JSON into the right class if this object can have two possibilities of unserialization?
Related
My goal is to build an API that can load currency data from https://openexchangerates.org/ api into our SQLite database. I am able to get the JSON object formatted like this:
When i run the code below, it returns an errors. I am not sure how to resolve this. Just need to convert this JSON into a C# class without error.
Here's the custom C# object to mapped to JSON obj:
public class ExchangeRate
{
public string Disclaimer { get; set; }
public string License { get; set; }
public string Timestamp { get; set; }
public string Base { get; set; }
public string Rates { get; set; }
}
Here is the api call where its returning the error:
public static async Task<List> GetLatest(string url)
{
var client = new HttpClient();
string results = await client.GetStringAsync(url);
List<ExchangeRate> ratesList = JsonConvert.DeserializeObject<List<ExchangeRate>>(results);
return ratesList;
}
The example JSON is not a list, it's a single object, this is specified in the exception message
...because the type requires a JSON array
, otherwise it would have [ ] around it indicating an array (can be deserialized to list). Also, your model is flawed as Rates is not a string, but an object, and Timestamp is not a string but a long for the datetime as ticks. Change your model like so:
public class ExchangeRate
{
//decorate your properties since the json string uses lowercase
[JsonProperty("disclaimer")]
public string Disclaimer { get; set; }
[JsonProperty("license")]
public string License { get; set; }
[JsonProperty("timestamp")]
public long Timestamp { get; set; }
[JsonProperty("base")]
public string Base { get; set; }
[JsonProperty("rates")]
public Rates Rates { get; set; }
}
public class Rates
{
//create the properties for the Rates class
}
OR make the rates property a Dictionary<string, decimal>, NOTE: this could fail if any key is duplicated.
public class ExchangeRate
{
//decorate your properties since the json string uses lowercase
[JsonProperty("disclaimer")]
public string Disclaimer { get; set; }
[JsonProperty("license")]
public string License { get; set; }
[JsonProperty("timestamp")]
public long Timestamp { get; set; }
[JsonProperty("base")]
public string Base { get; set; }
[JsonProperty("rates")]
public Dictionary<string, decimal> Rates { get; set; }
}
Change your code to this:
ExchangeRate rate = JsonConvert.DeserializeObject<ExchangeRate>(results);
Your C# class model does not match the incoming JSON data structure. Rates is an array of items, but you're treating it like a string in your C# model. Timestamp is a number but you're treating it like a string in your C# model.
public class ExchangeRate
{
public string Disclaimer { get; set; }
public string License { get; set; }
public int Timestamp { get; set; }
public string Base { get; set; }
public Dictionary<string, double> Rates { get; set; }
}
I am currently trying to learn to work with API systems using C# .net core 3 and Newtonsoft.
The following call to Steam API is what I am using
for specific game details. For example http://store.steampowered.com/api/appdetails?appids=72850
This returns JSON similar to this ( I have cut it down for simplicity )
{
"72850": {
"success": true,
"data": {
"type": "game",
"name": "The Elder Scrolls V: Skyrim",
"steam_appid": 72850,
"required_age": 0,
"is_free": false
}
}
}
Each return has the unique ID as the root in this case 72850 and I am at a loss on how to map this into an object class so I can process this data. The "data" element is what I am really interested in but as a beginner, I am at a loss.
This API indexes its response using the internal Identifier of the Item requested.
This is a common scenario and it's also a quite efficient method to organize objects based on an Indexer, which can then be used to store or retrieve these objects, from a database, for example.
A common way to deserialize JSON object indexed like this, is to use a Dictionary, where the Key is Indexer and the Value the RootObject of the class structure (the Model) that further describes the JSON properties.
Some notes on the current JSON:
The API looks like it's built to represent the JSON on a HTML document, since the internal strings are formatted ready for presentation on a HTML page. This can be less useful when used elsewhere and can also create a problem when deserializing.
I've added a trivial clean-up, replacing what can cause a problem for sure:
json = json.Replace(#"\/", "/").Replace(#"\t", "");
I've added some more properties and classes to those presented in the question: it may be useful to see when a JsonProperty attribute is needed and when is it's not. For example: the [JsonProperty("type")] attribute is added to the public string GameType { get; set; } property, since Type is a keyword that may be misinterpreted, as is Name etc.
Json.Net is not case sensitive, so the JSON property background can be assigned to a .Net property public Uri Background { get; set; } without problem.
A couple of WebSites that provide a free service to format, validate and convert JSON object to a class model:
JsonFormatter - Formatting, validation
QuickType - Multi-language Class Model generator
Download the JSON using the WebClient.DownloadString() method, clean up the JSON and deserialize:
var steamUri = new Uri("https://store.steampowered.com/api/appdetails?appids=72850")
string json = new WebClient(steamUri).DownloadString();
json = json.Replace(#"\/", "/").Replace(#"\t", "");
var steamObj = JsonConvert.DeserializeObject<Dictionary<long, SteamApps.SteamAppDetails>>(json);
Class structure:
public class SteamApps
{
public class SteamAppDetails
{
public bool Success { get; set; }
public Data Data { get; set; }
}
public class Data
{
[JsonProperty("type")]
public string GameType { get; set; }
[JsonProperty("name")]
public string GameName { get; set; }
[JsonProperty("steam_appid")]
public long SteamAppid { get; set; }
[JsonProperty("required_age")]
public long RequiredAge { get; set; }
[JsonProperty("is_free")]
public bool IsFree { get; set; }
[JsonProperty("short_description")]
public string ShortDescription { get; set; }
[JsonProperty("supported_languages")]
public string Languages { get; set; }
[JsonProperty("header_image")]
public string HeaderImage { get; set; }
public string WebSite { get; set; }
[JsonProperty("price_overview")]
public PriceOverview PriceOverview { get; set; }
public Dictionary<string, bool> Platforms { get; set; }
public List<Screenshot> Screenshots { get; set; }
public Uri Background { get; set; }
public List<Category> Categories { get; set; }
}
public class PriceOverview
{
public string Currency { get; set; }
public long Initial { get; set; }
public long Final { get; set; }
[JsonProperty("discount_percent")]
public decimal DiscountPercent { get; set; }
[JsonProperty("initial_formatted")]
public string InitialFormatted { get; set; }
[JsonProperty("final_formatted")]
public string FinalFormatted { get; set; }
}
public partial class Screenshot
{
[JsonProperty("id")]
public long Id { get; set; }
[JsonProperty("path_thumbnail")]
public string PathThumbnail { get; set; }
[JsonProperty("path_full")]
public string PathFull { get; set; }
}
public partial class Category
{
[JsonProperty("id")]
public long Id { get; set; }
[JsonProperty("description")]
public string Description { get; set; }
}
}
Since you only need the "Data" element from the json, it is fairly simple using Newtonsoft. First make a class with all the fields that the Data element contains as shown below:
public class Data
{
public string Type { get; set; }
public string Name { get; set; }
public long Steam_AppId { get; set; }
public int Required_Age { get; set; }
public bool Is_Free { get; set; }
}
Now in order to map the json response, which I'm assuming is stored in a string at the moment, you have to Deserialize it to map to your C# class. And you can do that very easily:
Edit: A more elegant solution which avoids all the string manipulation nuisance
//You already have this but I created it in order to test
string jsonResult = "{ \"72850\": " +
"{ \"success\": true, \"data\": " +
"{ \"type\": \"game\", \"name\": \"The Elder Scrolls V: Skyrim\", " +
"\"steam_appid\": 72850, \"required_age\": 0, \"is_free\": false } }";
//JObject is a class in Newtonsoft library for handling json objects
JObject jObject = JObject.Parse(jsonResult);
//Since you're sending a request to the api, either you already have the id
//"72850" or can extract it easily from uri. This line gets data's value
//by 1st searching for key = "72850" and then within that a key = "data"
JToken dataToken = jObject["72850"]["data"];
Data data = dataToken.ToObject<Data>();
Reference: https://www.newtonsoft.com/json/help/html/SerializingJSONFragments.htm
Older solution
//getting the value portion of data element/key
string jsonData = "{" + jsonResult.Substring(jsonResult.IndexOf("\"type"));
//removing the extra } from the end
jsonData = jsonData.TrimEnd('}');
//map the json string to a C# object
var dataObj = JsonConvert.DeserializeObject<Data>(jsonData);
So now you'll see the json values mapped to your Data object which in this case is dataObj. Feel free to ask questions if anything's not clear. Cheers!
I'm using the API of www.textlocal.in, which returns a JSON formatted object.
JSON
{
"warnings":[
{
"message":"Number is in DND",
"numbers":"917000000000"
}
],
"balance":900,
"batch_id":311110011,
"cost":1,
"num_messages":1,
"message":{
"num_parts":1,
"sender":"TXTLCL",
"content":"Test1"
},
"receipt_url":"",
"custom":"",
"inDND":[
"917000000000"
],
"messages":[
{
"id":"1350123781",
"recipient":918819437284
}
],
"status":"success"
}
My code with which I'm trying to parse the JSON:
private void button1_Click(object sender, EventArgs e)
{
var a = JsonConvert.DeserializeObject<List<jsonToObj[]>>(richTextBox1.Text);
}
public class jsonToObj
{
public warnings[] warnings { get; set; }
public int balance { get; set; }
public int batch_id { get; set; }
public int cost { get; set; }
public int num_messages { get; set; }
public message message { get; set; }
public string receipt_url { get; set; }
public string custom { get; set; }
public messages[] messages { get; set; }
public string status { get; set; }
}
public class warnings
{
public string message { get; set; }
public string numbers { get; set; }
}
public class messages
{
public string id { get; set; }
public int recipient { get; set; }
}
public class message
{
public int num_part { get; set; }
public string sender { get; set; }
public string content { get; set; }
}
I'm getting an exception with the following message:
Newtonsoft.Json.JsonSerializationException: 'Cannot deserialize the
current JSON object (e.g. {"name":"value"}) into type
'System.Collections.Generic.List`1[WindowsFormsApp1.Form2+jsonToObj[]]'
because the type requires a JSON array (e.g. [1,2,3]) to deserialize
correctly. To fix this error either change the JSON to a JSON array
(e.g. [1,2,3]) or change the deserialized type so that it is a normal
.NET type (e.g. not a primitive type like integer, not a collection
type like an array or List) that can be deserialized from a JSON
object. JsonObjectAttribute can also be added to the type to force it
to deserialize from a JSON object. Path 'warnings', line 1, position
12.'
First of all you have to figure out what your API returns.
Right now you're trying to parse a List of jsonToObj Arrays (List<jsonToObj[]>). You have to decide whether to use a jsonToObj[] or List<jsonToObj> or a simple jsonToObj which your API provides now:
var a = JsonConvert.DeserializeObject<jsonToObj>(richTextBox1.Text);
But this then throws:
JSON integer 918819437284 is too large or small for an Int32. Path 'messages[0].recipient', line 25, position 33."
So make sure you use a Long for that.
public class messages
{
public string id { get; set; }
public long recipient { get; set; }
}
Furthermore you can add inDND to your jsonToObj class if you need the info:
public class jsonToObj
{
...
public string[] inDND { get; set; }
...
}
Based on string you class structure should be like this :
public class Warning
{
public string message { get; set; }
public string numbers { get; set; }
}
public class Message
{
public int num_parts { get; set; }
public string sender { get; set; }
public string content { get; set; }
}
public class Message2
{
public string id { get; set; }
public long recipient { get; set; }
}
public class RootObject
{
public List<Warning> warnings { get; set; }
public int balance { get; set; }
public int batch_id { get; set; }
public int cost { get; set; }
public int num_messages { get; set; }
public Message message { get; set; }
public string receipt_url { get; set; }
public string custom { get; set; }
public List<string> inDND { get; set; }
public List<Message2> messages { get; set; }
public string status { get; set; }
}
It looks like your class structure is not proper, Make use of visual studio and generate C# class from json string and then using that generated class try to deserialize class.
Read : Visual Studio Generate Class From JSON or XML
I simulated your problem and made the following changes that worked:
Change the method that deserializes to this:
var a = JsonConvert.DeserializeObject<jsonToObj>(richTextBox1.Text);
The result of the JSON you receive is not a List, so it will not work to deserialize to List<>.
The recipient property of the messages class receives values larger than an integer, so it must be transformed into a long like this:
public long recipient { get; set; }
These changes solve your problem.
Looks like this is a very old post, still thought of answering.
First of all, your Json data is singular which means, either
var a = JsonConvert.DeserializeObject<List<jsonToObj[]>>(richTextBox1.Text);
or
var a = JsonConvert.DeserializeObject<List<jsonToObj>>(richTextBox1.Text);
may not work for you.
You can either try:
var a = JsonConvert.DeserializeObject<jsonToObj>(richTextBox1.Text);
or
enclose the data with [ and ], which would do the trick.
make sure your parsing single object vs list of objects.
I have a web api that returns a complex object that looks like this:
public class CanDeleteRumsaAttributeResponse
{
public CanDeleteRumsaAttributeResponse()
{
}
public CanDeleteRumsaAttributeResponse(int attributeId)
{
RumsaAttributeId = attributeId;
}
public int RumsaAttributeId { get; set; }
public bool AttributeFound { get; set; }
public List<RumsaRoom> AffectedRumsaRooms { get; set; } = new List<RumsaRoom>();
public List<RumsaAttribute> AffectedLinkedRumsaAttributes { get; set; } = new List<RumsaAttribute>();
[JsonIgnore]
public bool CanDelete
{
get
{
return AffectedRumsaRooms.Count == 0&&AttributeFound&&AffectedLinkedRumsaAttributes.Count==0;
}
}
}
When I debug it I can see that the controller return that object and that the list AffectedLinkedRumsaAttributes has several objects in the list
When the client receives the list all but the first object are null.
I've tried returning the object as Ok(CanDeleteRumsaAttributeResponse) and I've tried serializing it like this:
RoomAttributesUtils utils = new RoomAttributesUtils(db);
string json = JsonConvert.SerializeObject(utils.GetCanDeleteColor(id));
var response = this.Request.CreateResponse(HttpStatusCode.OK);
response.Content = new StringContent(json, Encoding.UTF8, "application/json");
return response;
In the second case I can search the json string and find the missing data.
So its being serialized in the second case.
I've checked fiddler to see what is being sent and I can see that something is not right in the json-data.
The missing objects gets values like $ref: "4" and so on, but nothing else.
Here is the json-string I'm afraid I dont know how to format it properly for Stackoverflow, but I think that the information is there as well, but when I look at it using a viewer, its not and it sure doesnt deserialize to the correct objects.
The other list in the object can have any number of objects and they all return fine. Also, other endpoints are returning lists of the same type perfectly fine.
The three objects have unique values on the Code property and they are V30, V31 and V12 (if you want to identify them in the json string).
Any ideas?
Here is the json string
{"RumsaAttributeId":4797,"AttributeFound":true,"AffectedRumsaRooms":[{"$id":"1","RoomName":"STÄD","RoomNumber":"U12102-1150","Building":"U1","PartOfBuilding":"21","Plan":"02","Number":"1150","RoomDescriptions":[],"IsDeleted":false,"PMs":[],"IDNR":"175D_40","Exclude":false,"Department":"VN40 Lokalvård","Comments":"","Area":"23.19","HygeneClass":null,"CeilingHeight":"","UniqueRoomId":"d00e5325-7918-4d01-b273-813a770b46ca-010591d3","SolviegHasOpenedThis":true,"LastSynchedFromRevit":"1900-01-01T00:00:00","LastUpdatedFromRevit":"1900-01-01T00:00:00","Id":25772}],"AffectedLinkedRumsaAttributes":[{"$id":"2","AMACode":"KBC.3211","Malning":"56-03510","AvaliableColors":[{"$id":"3","AvaliableMaterials":[{"$ref":"2"},{"$id":"4","AMACode":"MBE.221","Malning":"-","AvaliableColors":[{"$ref":"3"}],"RoomDescriptions":[],"Code":"V30","ShortDescription":"Kakel, vattenavvisande beklädnad","LongDescription":"-","Comment":"-","PartOfRoom":null,"PartOfRoomId":960,"Id":1438},{"$id":"5","AMACode":"MBE.222","Malning":"-","AvaliableColors":[{"$ref":"3"}],"RoomDescriptions":[],"Code":"V31","ShortDescription":"Kakel, vattentät beklädnad","LongDescription":"-","Comment":"-","PartOfRoom":null,"PartOfRoomId":960,"Id":1439}],"RoomDescriptions":[],"Code":"V31_01","ShortDescription":"Kakel, vattentät beklädnad","LongDescription":"Marazzi SistemC Arch ME83, kulör Bianco(vit)200x200x5 mm. Fog Mapei Ultracolor Plus kulör 111 Silver Grey","Comment":"På 1 fondvägg","PartOfRoom":null,"PartOfRoomId":960,"Id":4797}],"RoomDescriptions":[],"Code":"V12","ShortDescription":"Gipsskivor, hygienklass 2","LongDescription":"Hög standard, hygienklass 2\n","Comment":"-","PartOfRoom":null,"PartOfRoomId":960,"Id":1425},{"$ref":"4"},{"$ref":"5"}]}
I had a similar situation in which I found that due to circular references, the serialization was not completed.
public class Blog
{
public int BlogId { get; set; }
public string Url { get; set; }
public List<Post> Posts { get; set; }
}
public class Post
{
public int PostId { get; set; }
public string Title { get; set; }
public string Content { get; set; }
public int BlogForeignKey { get; set; }
[ForeignKey("BlogForeignKey")]
public Blog Blog {get;set;}
}
I just deleted the child to parent relationship and included the foreingkey anotation to the entity set.
public class Blog
{
public int BlogId { get; set; }
public string Url { get; set; }
[ForeignKey("BlogForeignKey")]
public List<Post> Posts { get; set; }
}
public class Post
{
public int PostId { get; set; }
public string Title { get; set; }
public string Content { get; set; }
public int BlogForeignKey { get; set; }
}
Also consider LoopReferenceHandling
I am developing an application in c# that gets the players backpack value on a game called TF2 using Backpack.tf's api.
At the moment the code is:
(MAIN CLASS)
JsonConvert.DeserializeObject<Json1>(json);
(END OF MAIN CLASS)
public class Json1 {
public static List<Json2> response { get; set; }
}
public class Json2
{
public static int success { get; set; }
public static int current_time { get; set; }
public static IEnumerable<Json4> players { get; set; }
}
public class Json4 {
public static int steamid { get; set; }
public static int success { get; set; }
public static double backpack_value { get; set; }
public static string name { get; set; }
}
I've cut out all the other crap out of the main class etc but suffice it to say that yes i've got the json code into the json string ready for deserializing (Tested it with Console.Writeline)
The problem is. Whenever I use things like Json4.name (when writing to console)
it always returns 0.
Sorry if I've made a stupid mistake but I think I've tried things like removing static, changing variable types etc but I still can't get it to work. Please note this is my first attemopt at deserializing Json code and I wrote the classes at bottom myself because some reason http://json2csharp.com/ didn't work. Heres the Json I am trying to deserialize:
{
"response":{
"success":1,
"current_time":1365261392,
"players":{
"0":{
"steamid":"76561198045802942",
"success":1,
"backpack_value":12893.93,
"backpack_update":1365261284,
"name":"Brad Pitt",
"stats_tf_reputation":2257,
"stats_tf_supporter":1,
"notifications":0
},
"1":{
"steamid":"76561197960435530",
"success":1,
"backpack_value":4544.56,
"backpack_update":1365254794,
"name":"Robin",
"notifications":0
}
}
}
}
(formatting messed up a bit. Also please excuse some spelling mistakes :) )
You have several problems with your code:
a) All your fields are static. Remove static; you need them to be instance members.
b) The response property in Json1 should be just a single instance, not a list.
c) Players needs to be a dictionary (or custom type), not an IEnumerable, since it is not an array in the JSON.
d) StreamId has really big numbers that will not fit into an int; change this to long (or string).
public class Json1
{
public Json2 response { get; set; }
}
public class Json2
{
public int success { get; set; }
public int current_time { get; set; }
public IDictionary<int, Json4> players { get; set; }
}
public class Json4
{
public long steamid { get; set; }
public int success { get; set; }
public double backpack_value { get; set; }
public string name { get; set; }
}