Develop Reference

Newtonsoft.Json.Linq.JArray.Parse(string)' has some invalid arguments

I am trying to extract data from D2L for the dropbox submissions using API's I have a link which returns a Json Array as per told on the documentation and from this Array I just need the Id feild nothing else.
I have tried to convert this Array into dynamic Object but that didn't help.
Here is my code.
var client = new RestClient("https://" + LMS_URL);
var authenticator = new ValenceAuthenticator(userContext);
string Link = "/d2l/api/le/1.12/UnitID/dropbox/folders/UniID/submissions/";
var request = new RestRequest(string.Format(Link));
request.Method = Method.GET;
authenticator.Authenticate(client, request);
var response = client.Execute(request);
string jsonString = Newtonsoft.Json.JsonConvert.SerializeObject(response.Content);
Response.Write(jsonString);
//var splashInfo = JsonConvert.DeserializeObject<ObjectD>(response.Content);
dynamic jsonResponse = JsonConvert.DeserializeObject(response.Content);
var parsedObject = jsonResponse.Parse(jsonResponse);
string json = jsonResponse;
var popupJson = parsedObject["id"].ToString();
What my goal is that grab the list of ID's from this response and loop through them, these ID's are the key for my next API route.
Here is a glance at what I get from the response:
[
{
"Id": 2021,
"CategoryId": null,
"Name": "Graded Assignment: Part 1",
"CustomInstructions": {
"Text": "Directions:\r\nCOMPLETE the following TestOut Activities\r\n\r\n1.2.10 Practice Questions\r\n1.3.8 Practice Questions\r\n\r\nGo to TestOut to complete the Assignment."
//Other properties omitted
}
//Other properties omitted
}
]

The outermost container in the JSON returned is an array, so you need to deserialize to a collection type as specified in the Newtonsoft's Serialization Guide: IEnumerable, Lists, and Arrays.
Since you only care about the Id property of the object(s) in the array, you can use JsonConvert.DeserializeAnonymousType to deserialize just the interesting value(s):
var ids = JsonConvert.DeserializeAnonymousType(response.Content, new [] { new { Id = default(long) } })
.Select(o => o.Id)
.ToList();
And if you are certain the outermost array will contain exactly one item, you can do:
var id = JsonConvert.DeserializeAnonymousType(response.Content, new [] { new { Id = default(long) } })
.Select(o => o.Id)
.Single();
Alternatively, if you think you will later need to deserialize additional properties, you could make an explicit data model as follows:
public class ObjectId
{
public long Id { get; set; }
}
And do:
var ids = JsonConvert.DeserializeObject<List<ObjectId>>(response.Content)
.Select(o => o.Id)
.ToList();
Notes:
You will need to determine from the API documentation whether long or int is more appropriate for the Id value.
As a general rule I recommend not parsing to dynamic because you lose compile-time checking for correctness. When dealing with completely free-form JSON, parsing to JToken may be a better solution -- but your JSON appears to have a fixed schema, so neither is necessary.
Demo fiddle here.

Serialize Enum Values and Names to JSON

This question is related, but IMHO not identical to
How do I serialize a C# anonymous type to a JSON string?
Serialize C# Enum Definition to Json
Whilst testing, I've also stumbled across this culprit LinqPad which made my life difficult:
Why does LINQPad dump enum integer values as strings?
Now, my actual question:
My application (in particular SyncFusion component datasources, such as MultiSelect) requires enumerations in JSON format, e.g. something like this:
[ {"Id":0,"Name":"Unknown"},{"Id":1,"Name":"Open"},{"Id":2,"Name":"Closed"},{"Id":3,"Name":"Approve"} ]
UPDATE
As dbc pointed out, my question may not have been clear enough. I do not want to serialize one entry of the enumeration, but the whole struct. The JSON could then be used for a data source in Javascript, e.g. for a , simplified:
<option value=0>Unknown</option>
<option value=1>Open</option> etc
The JSON object is identical to an Enum in a namespace (with the exception that I have given the a property name to the Key and Value of each entry:
public enum ListOptions
{
Unknown = 0,
Open = 1,
Closed = 2,
Approve = 3
}
I've struggled with Enums, all the other approaches such as specifying a Json StringConverter etc did't yield all options in an array, so I ended up using Linq. My View Model now has a string property like this:
public string CrewListOption => JsonConvert.SerializeObject(Enum.GetValues(typeof(ListOptions))
.Cast<int>()
.Select(e => new { Id = (int) e, Name = typeof(ListOptions).GetEnumName(e) }));
Given that I'm pretty much a beginner with ASP.Net Core, I find it hard to believe that this should be a good solution. Yet I find it hard to find straight-forward better examples of the same thing.
I'd appreciate it if you might be able to help me improve this, and make it potentially more generically useful to "export" whole enumerations to JSON.
Here's the full LinqPad (where Newtonsoft.Json is imported from GAC):
void Main()
{
Enum.GetValues(typeof(ListOptions)).Cast<int>().Select(e => new { Id = e, Name = (ListOptions) e } ).Dump(); // these are identical, except for the typeof()
Enum.GetValues(typeof(ListOptions)).Cast<int>().Select(e => new { Id = (int) e, Name = typeof(ListOptions).GetEnumName(e) }).Dump(); // is typeof(MyEnumType) better?
string JsonString = JsonConvert.SerializeObject(Enum.GetValues(typeof(ListOptions)).Cast<int>().Select(e => new { Id = (int) e, Name = typeof(ListOptions).GetEnumName(e) }));
JsonString.Dump(); // [{"Id":0,"Name":"Unknown"},{"Id":1,"Name":"Open"},{"Id":2,"Name":"Closed"},{"Id":3,"Name":"Approve"}]
}
public enum ListOptions {
Unknown = 0,
Open = 1,
Closed = 2,
Approve = 3
};

You may have static method like
public static EnumToDictionary<string, string> EnumToDictionary<T>() where T: Enum
{
var res = Enum.GetValues(typeof(T)).Cast<T>()
.ToDictionary(e => Convert.ToInt32(e).ToString(), e => e.ToString());
return res;
}
then for Serializing as object
var enumValues= EnumToDictionary<ListOptions>();
var result = JsonConvert.SerializeObject(enumValues);
for serializing as array
var enumValues= EnumToDictionary<ListOptions>().ToArray();
var result = JsonConvert.SerializeObject(enumValues);

Here is an example from Microsoft Docs that convert Enum to Dictionary
https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/generics/constraints-on-type-parameters#enum-constraints
Then you can serialize the dictionary to JSON.

Converting API call Json URL string (Json Objects) into C# Datatable (Without using any constructive class with getters and setters or poco)

I'm new to Json API call string parsing in C#, I have a requirement where I need to get Json string from a API call and convert that into C# data-table then show the results in a web page using Asp.Net GridView.
I tried several ways. I faced different type of issues in each approach only succeed with my Approach 4(mentioned below). But I don't want to create a separate class (With getter and setters) and converting Json string into object of that class. As I have more than 150 fields for each record in my Json file and also object names are dynamic they are generated randomly. I don't want one to one mapping (Class field to Json field).
Here is my Json file format,
{
"R_aabdcDgjZwp0ch":{ Record 1 information key value pair } // Here R_aabdcDgjZwp0ch are randomly generated value
"R_lkYnksdY6qXaPb":{ Record 2 information key value pair } //R_lkYnksdY6qXaPb random
………
"R_7GhjsnB29xWBjp":{ Record n information key value pair }//R_7GhjsnB29xWBjp not fixed value
}
Sample Records from Json string:
{
"R_3dSKpqkb0JuH0TW":{"ResponseSet":"Default Response Set","Name":"John, Smith","ExternalDataReference":"811221273","EmailAddress":"smithaa#gmail.com","IPAddress":"123.232.12.21","Status":"","StartDate":"2015-07-06 11:10:26","EndDate":"2015-07-06 11:10:55","Finished":"1","RecipientEmail":"smithaa#gmail.com","RecipientLastName":"John","RecipientFirstName":"Smith","MI":"Mia","EntryTerm":"","Classification":"","Type":"","MajorCode":"","Major":"","DeptCode":"","Dept":"","College":"","Age":"","Ethnicity":"","Gender":"","CB1":"","PIDM":"71121027","Military":"","OrientationDate":"4\/7\/2016","H1":1,"H2":1,"H3":2,"H4":2,"H5":"","Q1":"","Q2":"","Q3_1":"","Q3_2":"","Q3_3":"","Q3_4":"","Q3_5":"","Q3_6":"","Q3_7":"","Q3_7_TEXT":"","Q4_1":"","Q4_2":"","Q4_3":"","Q4_4":"","Q4_5":"","Q4_6":"","Q4_7":"","Q4_8":"","Q4_9":"","Q4_10":"","Q4_11":"","Q4_12":"","Q4_12_TEXT":"","Q5":"","Q5_TEXT":"","Q6_1":"","Q6_2":"","Q6_3":"","Q7":"","Q8":"","Q9":"","Q10_1":"","Q10_2":"","Q10_3":"","Q10_4":"","Q11_1":"","Q11_2":"","Q11_3":"","Q11_4":"","Q12_1":"","Q12_2":"","Q12_3":"","Q12_4":"","Q13":"","Q13_TEXT":"","Q14":"","Q14_TEXT":"","Q15_1":"","Q15_2":"","Q15_3":"","Q15_4":"","Q15_5":"","Q15_6":"","Q15_7":"","Q15_8":"","Q16_1":"","Q16_2":"","Q16_3":"","Q16_4":"","Q16_5":"","Q16_6":"","Q16_7":"","Q16_8":"","Q17_1":"","Q17_2":"","Q17_3":"","Q17_4":"","Q17_5":"","Q17_6":"","H6":"","Q18_1":"","Q18_2":"","Q18_3":"","Q19_1":"","Q19_2":"","Q19_3":"","Q19_4":"","Q20":"","Q21_1":"","Q21_2":"","Q22_1":"","Q22_2":"","Q23_1":"","Q23_2":"","Q23_3":"","Q23_4":"","Q24":"","Q24_TEXT":"","Q25":"","Q26":"","Q27":"","Q28":"","H7":"","Q29_1":"","Q29_2":"","Q29_3":"","Q29_4":"","Q29_5":"","Q30":"","Q30_TEXT":"","Q31":"","Q31_TEXT":"","Q32":"","Q33_1":"","Q33_2":"","Q33_3":"","Q33_4":"","Q33_5":"","Q33_6":"","Q33_6_TEXT":"","Q34":"","Q34_TEXT":"","Q35":"","Q35_TEXT":"","Q36_1":"","Q36_2":"","Q36_3":"","Q36_4":"","Q36_5":"","Q36_6":"","Q36_7":"","Q36_7_TEXT":"","Q37":"","H8":1,"H9":1},
"R_1kYrTV300hwdvPP":{"ResponseSet":"Default Response Set","Name":"priya, Sam","ExternalDataReference":"8901212","EmailAddress":"sam12#gmail.com","IPAddress":"123.232.12.21","Status":"","StartDate":"2015-07-06 11:14:18","EndDate":"2015-07-06 11:14:59","Finished":"1","RecipientEmail":"sam#gmail.com","RecipientLastName":"sam","RecipientFirstName":"priya","MI":"","EntryTerm":"","Classification":"","Type":"","MajorCode":"","Major":"","DeptCode":"","Dept":"","College":"","Age":"","Ethnicity":"","Gender":"","CB1":"","PIDM":"71121028","Military":"","OrientationDate":"6\/27\/2016","H1":1,"H2":1,"H3":2,"H4":2,"H5":"","Q1":"","Q2":"","Q3_1":"","Q3_2":"","Q3_3":"","Q3_4":"","Q3_5":"","Q3_6":"","Q3_7":"","Q3_7_TEXT":"","Q4_1":"","Q4_2":"","Q4_3":"","Q4_4":"","Q4_5":"","Q4_6":"","Q4_7":"","Q4_8":"","Q4_9":"","Q4_10":"","Q4_11":"","Q4_12":"","Q4_12_TEXT":"","Q5":"","Q5_TEXT":"","Q6_1":"","Q6_2":"","Q6_3":"","Q7":"","Q8":"","Q9":"","Q10_1":"","Q10_2":"","Q10_3":"","Q10_4":"","Q11_1":"","Q11_2":"","Q11_3":"","Q11_4":"","Q12_1":"","Q12_2":"","Q12_3":"","Q12_4":"","Q13":"","Q13_TEXT":"","Q14":"","Q14_TEXT":"","Q15_1":"","Q15_2":"","Q15_3":"","Q15_4":"","Q15_5":"","Q15_6":"","Q15_7":"","Q15_8":"","Q16_1":"","Q16_2":"","Q16_3":"","Q16_4":"","Q16_5":"","Q16_6":"","Q16_7":"","Q16_8":"","Q17_1":"","Q17_2":"","Q17_3":"","Q17_4":"","Q17_5":"","Q17_6":"","H6":"","Q18_1":"","Q18_2":"","Q18_3":"","Q19_1":"","Q19_2":"","Q19_3":"","Q19_4":"","Q20":"","Q21_1":"","Q21_2":"","Q22_1":"","Q22_2":"","Q23_1":"","Q23_2":"","Q23_3":"","Q23_4":"","Q24":"","Q24_TEXT":"","Q25":"","Q26":"","Q27":"","Q28":"","H7":"","Q29_1":"","Q29_2":"","Q29_3":"","Q29_4":"","Q29_5":"","Q30":"","Q30_TEXT":"","Q31":"","Q31_TEXT":"","Q32":"","Q33_1":"","Q33_2":"","Q33_3":"","Q33_4":"","Q33_5":"","Q33_6":"","Q33_6_TEXT":"","Q34":"","Q34_TEXT":"","Q35":"","Q35_TEXT":"","Q36_1":"","Q36_2":"","Q36_3":"","Q36_4":"","Q36_5":"","Q36_6":"","Q36_7":"","Q36_7_TEXT":"","Q37":"","H8":1,"H9":1}
}
I have tried several ways to parse/consume Json url string to Datatable. I’m receiving below errors.
Approach 1: Using Json.Net and directly converting from Json string to Data Table using Newtonsoft.Json. JsonConvert.DeserializeObject
Sample Code:
string url ="test.com/json...etc"; //Here actual url to call api
var json_data = string.Empty;
// attempt to download JSON data as a string
json_data = w.DownloadString(url); // we are passing API url here
DataTable items = JsonConvert.DeserializeObject<DataTable>(json_data); // Exception coming here
Exception: Newtonsoft.Json.JsonSerializationException: Unexpected JSON token when reading DataTable. Expected StartArray, got StartObject. Path '', line 1, position 1.
Approach 2: I have used http://json2csharp.com/# (Which Converts Json input file/Json url into constructive class which will have getters and setters with Root Object to access data from sub classes). But I end up with an exception. However I don't want this approach.
Exception: Newtonsoft.Json.JsonSerializationException: Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1[matrix+RANFpZfdGjZwp0ch]' 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 'R_ANFpZfdGjZwp0ch', line 1, position 21.
Approach 3: I have tried using below. But ended with an exception.
DataTable dt = (DataTable)JsonConvert.DeserializeObject(json, (typeof(DataTable)));
Exception: Newtonsoft.Json.JsonSerializationException: Unexpected JSON token when reading DataTable. Expected StartArray, got StartObject. Path '', line 1, position 1.
Tried below to solve this Approach 3 issue. But didn't work.
Newtonsoft.Json JsonConvert To Datatable
http://www.codeproject.com/Questions/817608/Newtonsoft-Json-JsonConvert-To-Datatable
Converting JSON string to DataTable
Parsing with Json.NET: "Unexpected token: StartObject"
Approach 4: With this approach I succeed using constructive class with getters and setters.
string url ="test.com/json...etc"; //Here actual url to call api
using (var w = new WebClient())
{
var json = string.Empty;
// attempt to download JSON data as a string
try
{
json = w.DownloadString(url);
}
catch (Exception) { }
User obj = new User(json);
Response.Write(obj.name);
}
public class User
{
/********* Used from https://stackoverflow.com/questions/2246694/how-to-convert-json-object-to-custom-c-sharp-object **********/
public User(string json)
{
JObject jObject = JObject.Parse(json);
JToken jUser = jObject["R_XYZanOp0ch"]; //R_XYZanOp0ch this value is randomly generated. I gave it constant to check for one record. In actual Json file there are so many randomly generated object names exist.
name = (string)jUser["Name"];
email = (string)jUser["Email"];
ExternalDataReference = (string)jUser["NumberReference"];
}
public string name { get; set; }
public string ExternalDataReference { get; set; } // student ID
public string email { get; set; }
}
I got some result using this Approach 4. But problem is that we have more than 150 fields and we don't want to make getters and setters for each field and object names are dynamic not fixed. Unfortunately we need all fields data.
Below are my references I used for above approaches.
Convert Json String to C# Object List
Convert JSON to DataTable
How to convert json into datatable?
Thanks for reading. Sorry for my long text. Don't consider this post as duplicate, As I tried all ways but still I didn't get desired outcome, hence posting here.
Can anyone help me or guide me as per my Json string structure, do I need to change any of code? Any samples or reading notes would be helpful.
Thank you.
Update : I tried both, I got System.FormatException: Input string was not in a correct format exception at array.ToObject(); please let me know If I miss any step in between.
var obj = JObject.Parse(json);
var array = new JArray(obj.Values());
//Response.Write("<br/>array[0]" + array[0].ToString()); // I could able to view the record 1 data
var dt = array.ToObject<DataTable>(); // Having issue here.

Json.NET has a built-in converter for DataTable. It formats the table as an array, like so:
[
{
"Column1Name" : value11,
"Column2Name" : value21
},
{
"Column1Name" : value12,
"Column2Name" : value22
},
// And so on
}
What you have is a dictionary with random keys, not an array, so you need to transform your JSON to an array before deserialization. This can be done with LINQ to JSON. If you do not need the random key names, you can do:
var obj = JObject.Parse(json);
var array = new JArray(obj.Values());
var dt = array.ToObject<DataTable>();
If you need the random key names, you could add them as a column to the DataTable like so:
var obj = JObject.Parse(json);
string keyColumnName = "__key";
var query = from p in obj.Properties()
select new JObject(p.Value.OfType<JProperty>().Concat(new [] { new JProperty(keyColumnName, p.Name) }));
var array = new JArray(query);
var dt = array.ToObject<DataTable>();
Sample fiddle.

Thank you dbc. I appreciate your input it helped me to figure out middle layer (Converting Json to Array) in between Json to DataTable.
I modified your code little bit and used data-table conversion method call from https://stackoverflow.com/a/24339121/4425471
At movement we are ignoring the Random Key. Finally I got my desired outcome. I can able to convert Json to DataTable and then to the GridView.
Here is my final code. Thank you SO.
string json = "test.com/json..."; // actual API call url
DataTable dt = toDataTable(json);
GridView1.DataSource = dt;
GridView1.DataBind();
public static DataTable toDataTable(string json)
{
var result = new DataTable();
var obj = JObject.Parse(json);
var jArray = new JArray(obj.Values());
//Initialize the columns
foreach (var row in jArray)
{
foreach (var jToken in row)
{
var jproperty = jToken as JProperty;
if (jproperty == null) continue;
if (result.Columns[jproperty.Name] == null)
result.Columns.Add(jproperty.Name,typeof(string));
}
}
foreach (var row in jArray)
{
var datarow = result.NewRow();
foreach (var jToken in row)
{
var jProperty = jToken as JProperty;
if (jProperty == null) continue;
datarow[jProperty.Name] = jProperty.Value.ToString();
}
result.Rows.Add(datarow);
}
return result;
}

How to cross join deserialization json data in C#

I have two lists of deserialized json data, and I want to cross join the tables. The example data is item1:name, item2:date for both lists. I have the return type as List but my return type is not valid. Not sure what I am doing wrong here.
What I have so far:
List<JsonData> jdOne = GetDeserializedData(jsonUrlOne);
List<JsonData> jdTwo = GetDeserializedData(jsonUrlTwo);
var query = from urlOne in jdOne
from urlTwo in jdTwo
select new { urlOne, urlTwo };
return query;

You probably want to use a Tuple to do this....
public List<Tuple<JsonData,JsonData>> myFunc() {
List<JsonData> jdOne = GetDeserializedData(jsonUrlOne);
List<JsonData> jdTwo = GetDeserializedData(jsonUrlTwo);
var query = from urlOne in jdOne
from urlTwo in jdTwo
select Tuple.Create(urlOne, urlTwo);
return query.ToList();
}
Then with your results you can access the two items like so.
var results=myFunc();
var x1=results[0].Item1;
var x2=results[0].Item2;
x1 contains the first pair from the first list result, x2 contains the second pair.

Is this what you want by using Linq: Zip
var result = jdOne.Zip(jdTwo, (urlOne, urlTwo) => new {urlOne, urlTwo});

Looks like you trying to return anonymous type from function. Declare type to hold both values, and return it
select new YourType(){Field1 = urlOne, Field2 = urlTwo}

json.net IEnumerable

I have the following json file
{"fields":[
{
"status":"active",
"external_id":"title",
"config":{},
"field_id":11848871,
"label":"Title",
"values":[
{
"value":"Test Deliverable"
}
],
"type":"text"
},{
"status":"active",
"external_id":"client-name",
"config":{},
"field_id":12144855,
"label":"Client Name",
"values":[
{
"value":"Chcuk Norris"
}
],
"type":"text"
}}
And I want to select the value of the field that has its external_id = "title" for example, I'm using Json.Net and already parsed the object. How do i do this using lambda or linq on the Json object, I trird something like this
JObject o = JObject.Parse(json);
Title = o["fields"].Select(q => q["extenral_id"].Values[0] == "title");
Which is not event correct in terms of syntax. I'm not very proficient in Lambda or Linq thought its been there for a while. Appreciate the help
Thanks
Yehia

Or you can do this:
string json = "{\"fields\":[{\"status\":\"active\",\"external_id\":\"title\",\"config\":{},\"field_id\":11848871,\"label\":\"Title\",\"values\":[{\"value\":\"Test Deliverable\"}],\"type\":\"text\"},{\"status\":\"active\",\"external_id\":\"client-name\",\"config\":{},\"field_id\":12144855,\"label\":\"Client Name\",\"values\":[{\"value\":\"Chcuk Norris\"}],\"type\":\"text\"}]}";
JObject obj = JObject.Parse(json);
JArray arr = (JArray)obj["fields"];
var externalIds = arr.Children().Select(m=>m["external_id"].Value<string>());
externalIds is a IEnumerable array of string
Or you can chain it together and select the object in one line:
var myVal = JObject.Parse(json)["fields"].Children()
.Where(w => w["external_id"].ToString() == "title")
.First();
From there you can append whatever selector you want ie if you want the external_id value then append ["external_id"].ToString() to the end of the first() selector.

Build classes for your objects first, then parse them so you can access them correctly and its no anonymous type anymore.
For example this classes:
class MyJson {
public List<MyField> fields {get;set;}
}
class MyField {
public string status {get;set;}
public string external_id {get;set;}
// and so on
}
Then use that class for parsing the json (don't know the exact syntax right now) like this:
var o = Json.Parse(json, typeof(MyJson));
And then you can select your data easily with Linq and have intellisense in VS (or similar dev env):
var myData = o.fields.Where(q=>q.external_id=="title");

If you had your JSON converted to objects (basically what Marc suggested), the LINQ query would look something like:
o.fields.Single(q => q.external_id == "title")
But if you don't want to do that, you have to access the values by string keys. If you don't want to convert the type of the value, you can simply use indexing (["key"]). But if you want to convert the type, you can use Value<Type>("key"). Putting it together, the whole query might be:
o["fields"].Single(q => q.Value<string>("external_id") == "title")