Develop Reference

Created Nested JSON array from JSON array

I am pretty new to JSON and C# and have created an Azure Function that ties back to Snowflake which requires a very specific type of JSON response. I would like assistance if any in turning a JSON response I'm getting to a slightly different formatted response.
{
"access_token": "access token value here" , "user": "user_val"
}
to looking like
{
"data":
[
[ 0, { "access_token" : "access token value here", "user" : "user_val" } ]
]
}
I need create a nested array with "data" as the parent and a row number response starting at 0.

Using Json.NET:
using System;
using System.Collections.Generic;
using Newtonsoft.Json;
public class Program
{
public static void Main()
{
string json = #"{
""access_token"": ""access token value here"" , ""user"": ""user_val""
}";
Access a = JsonConvert.DeserializeObject<Access>(json);
var accessCollection = new AccessCollection
{
Data = new List<Access> { a }
};
json = JsonConvert.SerializeObject(accessCollection, Formatting.Indented);
Console.WriteLine(json);
}
}
public class Access
{
[JsonProperty("access_token")]
public string AccessToken
{
get;
set;
}
[JsonProperty("user")]
public string User
{
get;
set;
}
}
public class AccessCollection
{
[JsonProperty("data")]
public List<Access> Data
{
get;
set;
}
}
In addition, I consider the inner array is not usual because the data type are int and object. In general, they should be of same type. Because of that, I use a single dimensional array instead.
Please modify the codes according to situation.
.NET Fiddle

Get JSON Data in variable when only one item is returned

I am trying to get some currency values from an api. it's returning the data in the following format:
{"PKR_PKR":{"val":1}}
I want to show this value in textbox but there's an error
"Object reference not set to an instance of object".
I've tried the following code:
try
{
string endPoint = #"http:urlhere";
string ResultJson = "";
using (WebClient wc = new WebClient())
{
ResultJson = wc.DownloadString(endPoint);
}
JsonData values = JsonConvert.DeserializeObject<JsonData>(ResultJson);
txtBalanceRate.Text = values.CurrencyValue.ToString();
}
catch (Exception ex) { }
Class code:
class JsonData
{
public object CurrencyValue { get; set; }
}
**
UPDATE
**
Note: I can not update PKR_PKR Class becuase every time the name of variable is different for different currencies i.e. it can be USD_PKR , EUR_PKR etc
How can I resolve this?
FOLLOWING IS THE UPDATED CODE:
try
{
string endPoint = #"http://free.currencyconverterapi.com/api/v5/convert?q="+ddlCurrency.SelectedValue.ToString()+"_PKR&compact=y";
string ResultJson = "";
using (WebClient wc = new WebClient())
{
ResultJson = wc.DownloadString(endPoint);
}
RootObject rootObject = JsonConvert.DeserializeObject<RootObject>(ResultJson);
txtBalanceRate.Text = rootObject.PKR_PKR.val.ToString();
}
catch (Exception ex)
{
}
public class PKRPKR
{
public int val { get; set; }
}
public class RootObject
{
public PKRPKR PKR_PKR { get; set; }
}

If you are going to have dynamic object then you should try this out
dynamic data = Newtonsoft.Json.JsonConvert.DeserializeObject(json);
Type typeOfDynamic = data.GetType();
if( typeOfDynamic.GetProperties().Where(p => p.Name.Equals("PKR_PKR")).Any())
{
console.WriteLine(data.PKR_PKR.val);
}
else if( typeOfDynamic.GetProperties().Where(p => p.Name.Equals("USD_PKR")).Any())
{
console.WriteLine(data.USD_PKR.val);
}
else if( typeOfDynamic.GetProperties().Where(p => p.Name.Equals("EUR_PKR")).Any())
{
console.WriteLine(data.EUR_PKR.val);
}
above way is not tried and tested but you can have try like this as you json is dynamic.
Above way is checking property exist or not and get val from dynamci object
Your class structure is incorrect can you please try below class structure
public class PKRPKR
{
public int val { get; set; }
}
public class RootObject
{
public PKRPKR PKR_PKR { get; set; }
}
RootObject rootObject = JsonConvert.DeserializeObject<RootObject>(json);
Console.WriteLine(rootObject.PKR_PKR.val);
Mostly if you see above class structure , you josn each node is represent as class, but I dont go in much detail as Visual studio can do it for me.
When comes to json to object conversion ,I make use of utility provided by Visual studio. which does conversion of json string to proper class structure. here is image of it
Read how to do it full here :
Visual Studio Generate Class From JSON or XML
If you dont have visual studio with this feature you can use this online utility : json2csharp

Note: I can not update PKR_PKR Class becuase evert time the name of
variable is different for different currencies i.e. it can be USD_PKR
, EUR_PKR etc How can I resolve this?
SOLUTION
if json string {"PKR_PKR":{"val":1}} is fixed in your case, you can use following solution for any currency name you got.
static void Main(string[] args)
{
string json1 = "{ \"PKR_PKR\":{ \"val\":1}}";
string json2 = "{ \"USD_PKR\":{ \"val\":2}}";
string json3 = "{ \"EUR_PKR\":{ \"val\":3}}";
JToken token1 = (JToken)JsonConvert.DeserializeObject(json1);
Console.WriteLine(token1.First().First()["val"]);
JToken token2 = (JToken)JsonConvert.DeserializeObject(json2);
Console.WriteLine(token2.First().First()["val"]);
JToken token3 = (JToken)JsonConvert.DeserializeObject(json3);
Console.WriteLine(token3.First().First()["val"]);
Console.ReadLine();
}

I think your receiving object should contain a dictionary, not a single string:
Check this
Or you have to improve your object structure implementing a root item which contains a PKR_PKR sub object

How to avoid fields when deserialize the JSON response directly into a strongly typed object?

I have a json response displayed as below. I am using datacontractserializer to serialize.
If I need only "text" and "created time" from this Json response...how should be my DataContract looks like?
Do I need to have all these six properties in my data contract ? and use "IgnoreDataMember" as attribute?
Also, do I need to give same name for my properties in datacontract (Ex : screenName, text as property name ?)
"abcDetails":[
{
"screenName":"my name",
"text":"tweet desc",
"createdTime":1423494304000,
"entities":{ },
"name":"abc",
"id":"123"
}]

To answer your questions:
You can omit properties that you do not need and DataContractJsonSerializer will skip over them.
You class's property names can differ from the JSON property names as long as you set the DataMemberAttribute.Name value to be the same as the name appearing in the JSON.
Your JSON is invalid, it is missing outer braces. I assume that's just a copy/paste error in your question.
Thus your classes could look like:
[DataContract]
public class Detail
{
[DataMember(Name="text")]
public string Text { get; set; }
[DataMember(Name="createdTime")]
public long CreatedTimeStamp { get; set; }
}
[DataContract]
public class RootObject
{
[DataMember(Name="abcDetails")]
public List<Detail> Details { get; set; }
}
And to test:
string json = #"
{
""abcDetails"":[
{
""screenName"":""my name"",
""text"":""tweet desc"",
""createdTime"":1423494304000,
""entities"":{ },
""name"":""abc"",
""id"":""123""
}]
}
";
var response = DataContractJsonSerializerHelper.GetObject<RootObject>(json);
foreach (var detail in response.Details)
{
Console.WriteLine(string.Format("Created Time: {0}; Text: \"{1}\"", detail.CreatedTimeStamp, detail.Text));
}
produces the output
Created Time: 1423494304000; Text: "tweet desc"
using the helper class:
public static class DataContractJsonSerializerHelper
{
public static T GetObject<T>(string json) where T : class
{
DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(T));
return GetObject<T>(json, serializer);
}
public static T GetObject<T>(string json, DataContractJsonSerializer serializer)
{
using (var stream = GenerateStreamFromString(json))
{
var obj = serializer.ReadObject(stream);
return (T)obj;
}
}
private static MemoryStream GenerateStreamFromString(string value)
{
return new MemoryStream(Encoding.Unicode.GetBytes(value ?? ""));
}
}

How to get property from dynamic JObject programmatically

I'm parsing a JSON string using the NewtonSoft JObject.
How can I get values from a dynamic object programmatically?
I want to simplify the code to not repeat myself for every object.
public ExampleObject GetExampleObject(string jsonString)
{
ExampleObject returnObject = new ExampleObject();
dynamic dynamicResult = JObject.Parse(jsonString);
if (!ReferenceEquals(dynamicResult.album, null))
{
//code block to extract to another method if possible
returnObject.Id = dynamicResult.album.id;
returnObject.Name = dynamicResult.album.name;
returnObject.Description = dynamicResult.albumsdescription;
//etc..
}
else if(!ReferenceEquals(dynamicResult.photo, null))
{
//duplicated here
returnObject.Id = dynamicResult.photo.id;
returnObject.Name = dynamicResult.photo.name;
returnObject.Description = dynamicResult.photo.description;
//etc..
}
else if..
//etc..
return returnObject;
}
Is there any way I can extract the code blocks in the "if" statements to a separate method e.g:
private void ExampleObject GetExampleObject([string of desired type goes here? album/photo/etc])
{
ExampleObject returnObject = new ExampleObject();
returnObject.Id = dynamicResult.[something goes here?].id;
returnObject.Name = dynamicResult.[something goes here?].name;
//etc..
return returnObject;
}
Is it even possible since we can't use reflection for dynamic objects. Or am I even using the JObject correctly?
Thanks.

Assuming you're using the Newtonsoft.Json.Linq.JObject, you don't need to use dynamic. The JObject class can take a string indexer, just like a dictionary:
JObject myResult = GetMyResult();
returnObject.Id = myResult["string here"]["id"];
Hope this helps!

Another way of targeting this is by using SelectToken (Assuming that you're using Newtonsoft.Json):
JObject json = GetResponse();
var name = json.SelectToken("items[0].name");
For a full documentation: https://www.newtonsoft.com/json/help/html/SelectToken.htm

with dynamic keyword like below:
private static JsonSerializerSettings jsonSettings;
private static T Deserialize<T>(string jsonData)
{
return JsonConvert.DeserializeObject<T>(jsonData, jsonSettings);
}
//if you know what will return
var jresponse = Deserialize<SearchedData>(testJsonString);
//if you know return object type you should sign it with json attributes like
[JsonObject(MemberSerialization = MemberSerialization.OptIn)]
public class SearchedData
{
[JsonProperty(PropertyName = "Currency")]
public string Currency { get; set; }
[JsonProperty(PropertyName = "Routes")]
public List<List<Route>> Routes { get; set; }
}
// if you don't know the return type use dynamic as generic type
var jresponse = Deserialize<dynamic>(testJsonString);

Confusion in fetching data from JSON

I am trying to use one web service which returns demanded data in json format. Now the actual point is I can fetch the data from the particular web service url in string.
string url= #"http://api.oodle.com/api/v2/listings?key=TEST&region=chicago&category=vehicle&format=json";
string jsonString = new WebClient().DownloadString(url);
Now the point is I get the data in string (in JSON format). But I dont know how to convert the string into JSON string and how to fetch data from this string.
Let me give you example so you can easily understand
if my jsonString is like
{
"current":{
"region":{
"id":"chicago",
"name":"Chicago"
},
"category":{
"id":"vehicle",
"name":"Cars & Vehicles",
"abbrev":"Vehicles"
},
"start":1,
"num":10
}
}
How can i get region_name from that string ? Hope you understand me ! Try to use Test Link !

Add a reference to System.Web and then add to your using section
using System.Web.Script.Serialization;
Then (using your example json string)
string jsonString = "{\"current\":{\"region\":{\"id\":\"chicago\",\"name\":\"Chicago\"},\"category\":{\"id\":\"vehicle\",\"name\":\"Cars & Vehicles\",\"abbrev\":\"Vehicles\"},\"start\":1, \"num\":10}}";
JavaScriptSerializer serializer = new JavaScriptSerializer();
CurrentRecord currentRecord = serializer.Deserialize<CurrentRecord>(jsonString);
string regionName = currentRecord.current.region.name;
Also add the following classes to your project:
[Serializable]
public class CurrentRecord
{
public current current;
}
[Serializable]
public class current
{
public region region;
public category category;
public int start;
public int num;
}
[Serializable]
public class region
{
public string id;
public string name;
}
[Serializable]
public class category
{
public string id;
public string name;
public string abbrev;
}

Are you processing the JSON return string in Java, or JavaScript?
If you are processing the JSON response string in Java, you may make use of GSON. Here is a tutorial showing you how: Parsing a JSON String into an object with GSON easily.
For your case, you need a class like:
class Current{
private Region region;
private Category category;
private int start;
private int num;
// getters and setters
class Region{
private String id;
private String name;
// getters and setters
}
class Category{
private String id;
private String name;
private String abbreviation;
// getters and setters
}
}
Else if you are processing this JSON response String in Javascript, then you can have a look at this: http://www.json.org/js.html
alert(jsonReturnString.current.region.name);