Develop Reference

How to get data value in string C#

I have an object like this. How can I parse the Name Surname from this object?
Object
{
"HasError":false,
"AlertType":"success",
"AlertMessage":"Operation has completed successfully",
"ModelErrors":[],
"Data":{
"Count":1,
"Objects":
[{
"Id":291031530,
"FirstName":"Alp",
"LastName":"Uzan",
"MiddleName":"",
"Login":"alp"
}]
}
}
I'm getting this data to an external api using HttpClient but I can't parse it by values. Can you help with this, the type of data is System.String

You have a couple of options. The most type-safe way would be to define C# classes which represent the schema of your JSON content and then deserialise into an instance of those like so:
public class Data
{
public int Count { get; set; }
public List<DataObject> Objects { get; set; }
}
public class DataObject
{
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string MiddleName { get; set; }
public string Login { get; set; }
}
public class MyJSONObject
{
public bool HasError { get; set; }
public string AlertType { get; set; }
public string AlertMessage { get; set; }
public Data Data { get; set; }
}
...
//Deserialise
var json = "<snip>";
var deserialised = JsonSerializer.Deserialize<MyJSONObject>(json);
//Extract the info you want
Console.WriteLine(deserialised.Data.Objects[0].LastName);
A second, more quick and dirty way to do it would be to parse the JSON into a JsonObject (this is using System.Text.Json) and then extract out the info you need:
var jsonObj = JsonObject.Parse(Properties.Resources.JSON);
var objectsArray = ((JsonArray)y["Data"]["Objects"]);
Console.WriteLine(objectsArray[0]["LastName"]);
A similar method would work with Newtonsoft.Json as well, although you'd need to use JObject instead of JsonObject and JArray rather than JsonArray in that case.

If you use c#, save output in string and serialize, usa this library
using Newtonsoft.Json;
JObject json = JObject.Parse(str);
string Name= json.Data.Objects[0].FirstName
string Surname = json.Data.Objects[0].Lastname

If you are using System.Text.Json:
var jsonObject= JsonSerializer.Deserialize<JsonObject>(jsonString);
Then you can use jsonObject["Data"]["Objects"][0]["FirstName"] to get the data.

How can I deserialise a JSON result where its Root is a unique ID into an Object class

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!

Parsing JSON using json.net, Array serialized as properties

I'm trying to deserialize json data formated in a way I haven't seen before.
I'm using json.net and C#.
The class corresponding to the json should be like this:
class Example
{
public Person[] data { get; set; }
}
class Person
{
public string Id { get; set; }
public string Nationality { get; set; }
public string Name { get; set; }
}
And this is how the json looks like:
{
data: {
"123": ["SWE", "Steve"],
"221": ["USA", "Bob"],
"245": ["CAN", "Susan"]
}
}
Is it possible using attributes or do I have to do it all myself?

Your variables on the data object (123, 221, 245) would a type List<string>().
With JSON.NET, your schema needs to match your data; types and names.
EDIT: Looking at your Person object, your POCO classes don't seem correct. You would need a structure like this:
public Data data { get; set; }
where data is...
public class Data
{
public List<string> 123 { get; set; }
...
}

How can I convert JSON to an object?

I'm very new to C# and playing around with Visual Studio and Xamarin.
I have a web service where I get a JSON result from looking like this:
{"Vorname": "MYNAME", "AusweisNr": "894", "MitgliedsNr": "33203", "returnstr": "None", "returncode": "0"}
What I'm trying to do is to use the data I get to fill some text fields with, but I don't understand how to get it converted. I've already played around a bit with JsonConvert but couldn't get it working.

Create a class with those properties:
public class SomeMeaningfulName
{
public string Vorname { get; set; }
public string AusweisNr { get; set; }
public string MitgliedsNr { get; set; }
public string returnstr { get; set; }
public string returncode { get; set; }
}
Then you can deserialize the string into that class:
var myObj = JsonConvert.DeserializeObject<SomeMeaningfulName>(yourJsonString);

You can create a simple class like this:
public class Person
{
public string Vorname { get; set; }
public string AusweisNr { get; set; }
public string MitgliedsNr { get; set; }
public string returnstr { get; set; }
public string returncode { get; set; }
}
And to deserialize it:
string json = "{'Vorname': 'MYNAME', 'AusweisNr': '894', 'MitgliedsNr': '33203', 'returnstr': 'None', 'returncode': '0'}"
Person person = new JavaScriptSerializer().Deserialize<Person>(json);
In this case I use JavascriptSerializer because it very simple to use but you can also use JSONConverter if you realy need it

In order to convert using JsonConvert, you need to have a class with fields that share the names of your JSON object and they all need to be public. Try this
class MyJsonObject
{
public string Vorname;
public int AusweisNr;
public int MitgliedsNr;
public string returnstr;
public int returncode;
}
If you want, you could also make it a public property rather than a variable. To convert, you need to do something like this.
MyJsonObject obj= JsonConvert.DeserializeObject<MyJsonObject>(jsonData);
Where jsonData is a string containing your JSON code. You can then copy all the data to a text field.

Get your JSON string and set in this WebSite, this website will create a class object for you, take this object and put in your project.
example:
public class RootObject // object name
{
//atributtes names
public string Vorname { get; set; }
public string AusweisNr { get; set; }
public string MitgliedsNr { get; set; }
public string returnstr { get; set; }
public string returncode { get; set; }
}
So you will dowloand this JSON and put in a String var
example:
var Apiurl = "http://youAPI.com/something/something/";
var JSONString= new System.Net.WebClient().DownloadString(Apiurl);//this will download all text what the Apiurl return
After that, you will put convert/Deserialize your JsonString in a object.
RootObject objectJSON = JsonConvert.DeserializeObject<RootObject>(JSONString);
whats happen in this last code?
yourJsonObject nameForThisObject = JsonConvert.DeserializeObject<yourObjectJsonClass>(yourJsonString);
note: your ObjectJsonClass(my RootObject) must have the sames Json's attributes.

Problems with DeserializeObject with an json array

So I have a problem with DeserializeObject with an json array and I cant find what I am doing wrong here:
{"name":"Pannbiff n\u00f6tf\u00e4rs stekt","number":1128,"nutrientValues":
{"energyKj":694,"energyKcal":166,"protein":17.2,"fat":7.6,"carbohydrates":7}}
My model looks like this:
And my code looks like:
var responseText = streamReader.ReadToEnd();
var jsonSerializer = JsonConvert.DeserializeObject(responseText);
public class Asware
{
public IEnumerable<NutrientValues> nutrientValues { get; set; }
}
public class NutrientValues
{
public int energyKcal { get; set; }
public double protein { get; set; }
public double carbohydrates { get; set; }
public int fat { get; set; }
}
Can't see what can be wrong here I have also tried:
JsonConvert.DeserializeObject>(responseText)

The problem here is that in your source JSON, nutrientValues is a single object, not an array of objects.
If you change your model as follows it should serialise correctly:
public class Asware
{
public NutrientValues nutrientValues { get; set; }
}
Alternatively, if you have control of the JSON, then you can modify it to contain an array of nutrients as follows, the [ ] characters indicate multiple items.
{"name":"Pannbiff n\u00f6tf\u00e4rs stekt","number":1128,"nutrientValues":
[{"energyKj":694,"energyKcal":166,"protein":17.2,"fat":7.6,"carbohydrates":7}]}