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Access JSON keys in C# from ServiceNow Rest API

I am calling the ServiceNow Incidents table and pulling back one incident like this. https://mydevInstance.service-now.com/api/now/v1/table/incident?sysparm_limit=1
var client = new RestClient("https://mydevInstance.service-now.com/api/now/v1/table/incident?sysparm_limit=1");
client.Timeout = -1;
var request = new RestRequest(Method.GET);
request.AddHeader("Authorization", "Basic myAuthKey");
IRestResponse response = client.Execute(request);
The JSON it returns in RESTSharp looks like this.
{
"result": [
{
"parent": "",
"made_sla": "true",
"caused_by": "",
"watch_list": "",
"upon_reject": "cancel",
"resolved_by": {
"link": "https://mydevInstance.service-now.com/api/now/v1/table/sys_user/5137153cc611227c000bbd1bd8cd2007",
"value": "5137153cc611227c000bbd1bd8cd2007"
},
"approval_history": "",
"number": "INC0000060"
}
]
}
How do I create a C# list or array of all the Keys under result? I can't Serialize the object with JSON.Net because additional keys can be added over time.

You need to grab the sample of the JSON content, then make a C# class using the 'Paste Special' option I described.
Then you can use the JsonConvert.DeserializeObject<T> (in a nuget package by Newtonsoft) to deserialize your web service response in a C# object instance.
Here are the C# classes I generated with your JSON object unaltered:
public class Rootobject
{
public Result[] result { get; set; }
}
public class Result
{
public string parent { get; set; }
public string made_sla { get; set; }
public string caused_by { get; set; }
public string watch_list { get; set; }
public string upon_reject { get; set; }
public Resolved_By resolved_by { get; set; }
public string approval_history { get; set; }
public string number { get; set; }
}
public class Resolved_By
{
public string link { get; set; }
public string value { get; set; }
}
You use this type like this:
var json = "t-b-d"; // From Web Service call
Rootobject response = JsonConvert.DeserializeObject<Rootobject>(json);
// use the response object.
** UPDATED **
If you need a more flexible model, all JSON will deserialize into Dictionary<string, string>, but I have found that serialization / deserialization results are more reliable when the model is consistent
var response = JsonConvert.DeserializeObject<Dictionary<string,string>>(json);

Here is what does work using System.Text.Json
var incidentFields = new List<string>();
var doc = JsonDocument.Parse(json);
foreach (var o in doc.RootElement.GetProperty("result").EnumerateArray())
{
foreach (var p in o.EnumerateObject())
{
incidentFields.Add(p.Name.ToString());
}
}

I created a library that handles that by default. (You can add custom types also)
https://autodati.github.io/ServiceNow.Core/

Parsing data from json in C#

I successfully got data to var content
The code how I did it:
public async void FetchAsync()
{
var client = new RestClient("http://api.locopal.com");
var request = new RestRequest("/countries", Method.POST);
var response = client.Execute(request);
var content = response.Content;
var responseCountries = JArray.Parse(JObject.Parse(content)[""].ToString());
}
But in line: var responseCountries = JArray.Parse(JObject.Parse(content)[""].ToString()); I got An unhandled exception occured.
This is the data from var content:
Countries from here need to be write down to list.

You could declare a class like the following
public class Country
{
[JsonProperty("id")]
public int Id { get; set; }
[JsonProperty("nicename")]
public string Name { get; set; }
}
and then deserialize the json as below:
var responseCountries = JsonConvert.DeserializeObject<IEnumerable<Country>>(content);

You should deserialize the JSON into an object. You can create a POCO object with the properties from the JSON.
Example:
public class Country
{
[JsonProperty("id")]
public int Id { get; set; }
[JsonProperty("nicename")]
public string Name { get; set; }
}
Edit: Follow same casing as in JSON

How to convert HttpResponseMessage having OData to a C# object?

I am calling a REST service from my C# application which connects to CRM.
This returns HttpResponseMessage.
response.Content.ReadAsStringAsync().Result
The above statement returns following output. I need to convert this to Account object, which already has "accountnumber, and accountid properties.
{
"#odata.context":"https://APIURL/api/data/v8.1/$metadata#account(accountnumber)","value":[
{
"#odata.etag":"W/\"12496866\"","accountnumber":"D00208","accountid":"30417c0f-7b8c-e611-80f3-5065f38bd4d1"
} ] }
I have tried following code
Account return = JsonConvert.DeserializeObject<Account>(response.Content.ReadAsStringAsync().Result);
But this doesn't fill up the object, and it always has null values in accountnumber, and accountid fields.
Any idea of how to properly convert this response to the C# type.

you should do it like this -
public class Value
{
[JsonProperty("#odata.etag")]
public string etag { get; set; }
public string accountnumber { get; set; }
public string accountid { get; set; }
}
public class RootObject
{
[JsonProperty("#odata.context")]
public string context { get; set; }
public List<Value> value { get; set; }
}
then deserialize-
var value = JsonConvert.DeserializeObject<RootObject>(json);

We can parse and create Anonymous Type based on that. In your case, replace the Anonymous Type with Account object.
Given the JSON string:
string json = #"{
'#odata.context':'https://APIURL/api/data/v8.1/$metadata#account(accountnumber)',
'value':[
{
'#odata.etag':'W/\'12496866\'',
'accountnumber':'D00208',
'accountid':'30417c0f-7b8c-e611-80f3-5065f38bd4d1'
}
]
}";
It can be parsed as below:
var jsonObject = JObject.Parse(json);
var dataObject = new
{
Context = jsonObject["#odata.context"],
Values = jsonObject["value"].AsEnumerable<JToken>()
.Select(v => new
{
ETag = v["#odata.etag"],
AccountNumber = v["accountnumber"],
AccountId = v["accountid"]
}).ToArray()
};
In order to convert to Account object where the object is defined as below:
public class Account
{
public string Number { get; set; }
public string Id { get; set; }
}
Then the JSON object can be parsed as below (if looking for only first node; It can also be converted to list of Accounts:
var jsonObject = JObject.Parse(json);
var account = jsonObject["value"].AsEnumerable<JToken>()
.Select(v => new Account()
{
Number = v["accountnumber"].ToString(),
Id = v["accountid"].ToString()
}).FirstOrDefault();

You can generalize the accepted answer by using a generic class to deserialize json web response:
class RootObject<T>
{
public List<T> Value { get; set; }
}
var odata = JsonConvert.DeserializeObject<RootObject<POCO>>(json);
Try it with live Demo

write data from JSON in C#

I have JSON like this:
{
'surveys': [
{
'title': 'first',
'id': 100,
},
{
'title': 'second',
'id': 101,
},
{
'title': 'third',
'id': 102,
},
]
}
I want to have the output like this:
title: first
title: second
title: third
and my program in C# is like this:
WebClient client = new WebClient();
var json = client.DownloadString("http://www.test.com/api/surveys/?api_key=123");
Debug.WriteLine(json); //write all data from json
//add
var example = JsonConvert.DeserializeObject<Example>(json);
Debug.WriteLine(example.Data.Length);
class Example
{
public surveys[] Data { get; set; }
}
class surveys
{
public string title { get; set; }
public int id { get; set; }
}
I get this error:
Thrown: "Object reference not set to an instance of an object." (System.NullReferenceException) Exception Message = "Object reference not set to an instance of an object.", Exception Type = "System.NullReferenceException", Exception WinRT Data = ""
at this line: Debug.WriteLine(example.Data.Length);
where is the problem?

One problem I see is that your outer class has a property named Data, which is an array of 'surveys' objects, but your Json has a list of 'surverys' objects under the property 'surveys'. Hence the 'Data' property is never populated.
Consider the following C# class structure:
class Example
{
public survey[] surveys{ get; set; }//Data renames to surveys
}
class survey //Singular
{
public string title { get; set; }
public int id { get; set; }
}

Why can't you do so?:
JObject data = JObject.Parse(json);
foreach (var survey in data["surveys"].Children())
{
Debug.WriteLine("title: " + survey["title"]);
}

You need to use JSON.Net and use the class JsonConvert and the method DeserializeObject<T>.
If you run this:
JsonConvert.DeserializeObject<JObject>();
Then you will get back a list of de-serialized JObject objects.
Use, NuGet to download the package. I think it is called JSON.net.
Here is the weblink
WebClient client = new WebClient();
var json = client.DownloadString("http://www.test.com/api/surveys/?api_key=123");
Debug.WriteLine(json); //write all data from json
//add
var example = JsonConvert.DeserializeObject<Survey>(json);
Debug.WriteLine(example.length); // this could be count() instead.
class Survey
{
public string title { get; set; }
public int id { get; set; }
}
This should work!

Use json2csharp to generate c# classes from json.
You will also need to use Json.NET.
public class Survey
{
public string title { get; set; }
public int id { get; set; }
}
public class RootObject
{
public List<Survey> surveys { get; set; }
}
Then you can do:
var client = new WebClient();
string json = client.DownloadString(some_url);
RootObject root = JsonConvert.DeserializeObject<RootObject>(json);
foreach (Survey s in root.surveys)
{
// Do something with your survey
}
Don't forget to use Newtonsoft.Json namespace once you add a reference to it within your project.
using Newtonsoft.Json;
Edit: I have tested it using:
string json = "{'surveys': [{'title': 'first','id': 100,},{'title': 'second','id': 101,},{'title': 'third','id': 102,},]}";
instead of using the WebClient, and it works.

JavaScriptDeseializer : Can not serialize array

My application is asp.net. I have to send some values back to server. For this I create a object serialize it and send it to server. At server I try to de-serialize it
Following is my code
[Serializable]
public class PassData
{
public PassData()
{
}
public List<testWh> SelectedId { get; set; }
public string SelectedControlClientId { get; set; }
public string GroupTypeId { get; set; }
public string SectionTypeId { get; set; }
}
[Serializable]
public class testWh
{
public testWh()
{
}
public string Id { get; set; }
}
JavaScriptSerializer serializer = new JavaScriptSerializer();
//this can not serialize the SelectedId and the count remains 0
PassData data = serializer.Deserialize<PassData>(jsonString);
//this serialize in an anonymous object with key value pair
var data2 = serializer.DeserializeObject(textHiddenArguments.Text);
Following is my Json Serialized String
{
"SelectedId":{"0":"ABCD","1":"JKLM"},
"SelectedControlClientId":"YTUTOOO",
"GroupTypeId":3,
"SectionTypeId":"1"
}
quotes escaped string
"{\"SelectedId\":{\"0\":\"ABCD\",\"1\":\"JKLM\"},\"SelectedControlClientId\":\"YTUTOOO\",\"GroupTypeId\":3,\"SectionTypeId\":\"1\"}"
My Problem is Selected Id is array of testWH object. But when I try to desrialize it, the SelectedId property of PassData which is list does not get serialized and count remains zero.
I tried using array instead of List, which gave an exception "no parameter less constructor..."
Could any one explain the what I am doing wrong here ?

The key problem here is that the JSON doesn't match the objects you have constructed. You can see this by writing the data you want and serializing:
var obj = new PassData
{
SelectedId = new List<testWh>
{
new testWh { Id = "ABCD"},
new testWh { Id = "JKLM"}
},
GroupTypeId = "3",
SectionTypeId = "1",
SelectedControlClientId = "YTUTOOO"
};
string jsonString = serializer.Serialize(obj);
which gives JSON like:
{"SelectedId":[{"Id":"ABCD"},{"Id":"JKLM"}],
"SelectedControlClientId":"YTUTOOO","GroupTypeId":"3","SectionTypeId":"1"}
So now you need to decide which you want to change; the JSON or the classes. The following alternative class works fine with your original JSON, for example:
public class PassData
{
public Dictionary<string,string> SelectedId { get; set; }
public string SelectedControlClientId { get; set; }
public string GroupTypeId { get; set; }
public string SectionTypeId { get; set; }
}