Develop Reference

How to deserialize this JSON to a List?

I have an issue with deserializing the JSON file from the web to a List.
My code is down below, but it does not execute and shows System.NullReferenceException. It happens in the Content() method, when I call callApiAsync() in the List.
class Program
{
static void Main(string[] args)
{
Content();
Console.ReadKey();
}
private async static void Content()
{
List<Coin> coins = await callApiAsync();
for (int i = 0; i < coins.Count; i++)
{
Console.WriteLine(coins[i].price);
}
}
static async Task<List<Coin>> callApiAsync()
{
string url = "https://api.coinstats.app/public/v1/charts?period=all&coinId=bitcoin";
HttpClient httpClient = new HttpClient();
var httpResponse = await httpClient.GetAsync(url);
string jsonResponse = await httpResponse.Content.ReadAsStringAsync();
var data = JsonConvert.DeserializeObject<Root>(jsonResponse);
return data.coins;
}
}
public class Root
{
public List<Coin> coins { get; set; }
}
public class Coin
{
public int time { get; set; }
public int price { get; set; }
}
My JSON for example:
{
"chart":[
[
1372032000,
107.979,
1,
0
],
[
1372118400,
102.982,
1,
0
],
[
1372204800,
103.34,
1,
0
]
]
}

The sample JSON you gave:
{"chart":[[1372032000,107.979,1,0],[1372118400,102.982,1,0],[1372204800,103.34,1,0]]}
Does not have a type that matches the "Root" class you are trying to deserialize to.
You can paste your JSON into a site like https://json2csharp.com/ to find out what the corresponding C# class should look like. In this case, the Root class should look like the following to support deserializing the specified JSON:
public class Root
{
public List<List<double>> chart { get; set; }
}
My guess is that you then intend to interpret the first value in each list as some sort of time stamp, the second value as a "price", and ignore the second and third values in each list. You will have to do the legwork for this after first deserializing the JSON to a list of lists of doubles.
For example:
var data = JsonConvert.DeserializeObject<Root>(jsonResponse);
return data.chart.Select(listOfDoubles => new Coin
{
time = (int)listOfDoubles[0],
price = listOfDoubles[1]
}).ToList();

You only need one string of code to deserialize
return JObject.Parse(jsonResponse)["chart"]
.Select(x => new Coin { time = UnixSecondsToDateTime( (long) x[0]),
price = (decimal)x[1] }
).ToList();
public class Coin
{
public DateTime time { get; set; }
public decimal price { get; set; }
}
public static DateTime UnixSecondsToDateTime(long timestamp, bool local = false)
{
var offset = DateTimeOffset.FromUnixTimeSeconds(timestamp);
return local ? offset.LocalDateTime : offset.UtcDateTime;
}

Unfortunately the API documentations do not tell anything about the response (1, 2).
So, if we can assume that the first number represents an epoch timestamp and the second the average price then you can parse the response with Linq2Json like this
var chart = JObject.Parse(jsonResponse)["chart"] as JArray;
List<(int Time, int Price)> coins = new();
foreach (JArray coin in chart)
{
coins.Add(((int)coin[0], (int)coin[1]));
}

Compare JSON array and JSON object: Cannot convert Array to String error

I am trying to compare json value and based on that i want to update the existing value,for example, currently we have "value" : [r0] in json, i want to compare and if value : [r0] ,then update it to [r0,r1] but iam hiting error that it cannot compare and there is a cast issue, could someone suggest what could be done
public void updateJsonParameter(string file)
{
try
{
var list = new List<string> { "joe", "test" };
JArray array = new JArray(list);
var jobject = JObject.Parse(file);
var ringvalue = (string)jobject["properties"]["parameters"]["ringValue"]["value"]; // unable to case here and compare
jobject["properties"]["parameters"]["ringValue"]["value"] = array; // able to update value but i want to update after comparing the existing values
var result = JsonConvert.SerializeObject(jobject);
}
following is the json format
{
"properties": {
"displayName": "jayatestdefid",
"description": "test assignment through API",
"metadata": {
"assignedBy": "xyz#gmail.com"
},
"policyDefinitionId": "/providers/Microsoft.Management/managementgroups/MGTest/providers/Microsoft.Authorization/policyDefinitions/test",
"parameters": {
"ringValue": {
"value": ["r0"]
}
},
"enforcementMode": "DoNotEnforce",
}
}

jobject.properties.parameters.ringValue.value is an array ["r0"] with one element "r0". If you want to check if it's an array with one element and that element is "r0", do exactly that:
var ringvalue = jobject["properties"]["parameters"]["ringValue"]["value"];
if(ringvalue.length == 1 && ringvalue[0] == "r0")
jobject["properties"]["parameters"]["ringValue"]["value"] = array;

You could compare the ringvalue (which is an JArray) using JArray.DeepEquals and then replace if the comparison returns true. For example,
var list = new List<string> { "joe", "test" };
JArray array = new JArray(list);
JArray valueToCompare = new JArray(new[]{"r0"});
var ringvalue = (JArray)jobject["properties"]["parameters"]["ringValue"]["value"];
if(JArray.DeepEquals(ringvalue,valueToCompare))
{
jobject["properties"]["parameters"]["ringValue"]["value"] = array;
}

First, as Klaycon said in his answer, it's worth noting that your "value" is not a single string. In json, whenever you see [ and ] then you have a collection, or an array, or a list.
When I work with json strings, I always like to be able to convert them into a strongly typed object. There is a very handy online tool I use all the time: http://json2csharp.com/
I took your json string that you provided and pasted it into that website. Here is that your object(s) look like when converted into c# classes:
public class RootObject // You can name this whatever you want
{
public Properties properties { get; set; }
}
public class Metadata
{
public string assignedBy { get; set; }
}
public class RingValue
{
public List<string> value { get; set; }
}
public class Parameters
{
public RingValue ringValue { get; set; }
}
public class Properties
{
public string displayName { get; set; }
public string description { get; set; }
public Metadata metadata { get; set; }
public string policyDefinitionId { get; set; }
public Parameters parameters { get; set; }
public string enforcementMode { get; set; }
}
Now, we can easily do the logic you need as follows:
// This is your json string, escaped and turned into a single string:
string file = "{ \"properties\": { \"displayName\": \"jayatestdefid\", \"description\": \"test assignment through API\", \"metadata\": { \"assignedBy\": \"xyz#gmail.com\" }, \"policyDefinitionId\": \"/providers/Microsoft.Management/managementgroups/MGTest/providers/Microsoft.Authorization/policyDefinitions/test\", \"parameters\": { \"ringValue\": { \"value\": [\"r0\"] } }, \"enforcementMode\": \"DoNotEnforce\", }}";
// Convert your json string into an instance of the RootObject class
RootObject jobject = JsonConvert.DeserializeObject<RootObject>(file);
// Get a list of all the "values"
List<string> values = jobject.properties.parameters.ringValue.value;
// Loop over your colleciton of "value" and do your logic
for (int i = 0; i < values.Count; ++i)
{
if (values[i] == "r0")
{
values[i] = "r0,r1";
}
}
// And finally, turn your object back into a json string
var result = JsonConvert.SerializeObject(jobject);
And this is the final result:
{
"properties":{
"displayName":"jayatestdefid",
"description":"test assignment through API",
"metadata":{
"assignedBy":"xyz#gmail.com"
},
"policyDefinitionId":"/providers/Microsoft.Management/managementgroups/MGTest/providers/Microsoft.Authorization/policyDefinitions/test",
"parameters":{
"ringValue":{
"value":[
"r0,r1"
]
}
},
"enforcementMode":"DoNotEnforce"
}
}

How to itrate JSON object?

I trying to get the id and email list from the JSON. How can i achieve this?
My JSON string is
{
"name":"name1",
"username":"name1",
"id":505,
"state":"active",
"email":"name1#mail.com",
},
{
"name":"name2",
"username":"name2",
"id":504,
"state":"active",
"email":"name2#mail.com",
}
My code is
Dictionary<string, string> engineers = new Dictionary<string, string>();
using (StreamReader r = new StreamReader(#"D:\project\Gitlap\EngineerEmail\jsonlist5.json"))
{
using (JsonTextReader reader = new JsonTextReader(r))
{
JObject o2 = (JObject)JToken.ReadFrom(reader);
string id = o2["id"].ToString();
string email = o2["email"].ToString();
engineers.Add(email, id);
}
}
class UserItems
{
public string id { get; set; }
public string email { get; set; }
}
I can able to get the first person`s mail ID and ID details. I need to iterate this JSON and get all the mail ID and ID.
I don`t know that how to iterate this JSON. I tried some method from the internet but that was not succeeded.
How can I do?

First thing is your JSON input is not valid json, you need to fix it. There are two issues in it. Its not collection of json objects and comma is missing between two objects.
Valid json should look like below.
[{
"name":"name1",
"username":"name1",
"id":505,
"state":"active",
"email":"name1#mail.com",
},
{
"name":"name2",
"username":"name2",
"id":504,
"state":"active",
"email":"name2#mail.com",
}]
Now define a c# class representing your json object.
public class User
{
public string name { get; set; }
public string username { get; set; }
public int id { get; set; }
public string state { get; set; }
public string email { get; set; }
}
Use JSON.Net library to deserialize it as shown below.
private void button1_Click(object sender, EventArgs e)
{
if(File.Exists("json1.json"))
{
string inputJSON = File.ReadAllText("json1.json");
if(!string.IsNullOrWhiteSpace(inputJSON))
{
var userList = JsonConvert.DeserializeObject<List<User>>(inputJSON);
}
}
}

JObject o2 = (JObject)JToken.ReadFrom(reader);
foreach(var obj in o2)
{
string id = obj["id"].ToString();
string Email= obj["Email"].ToString();
engineers.Add(email, id);
}

I would recommend using the Json.NET NuGet package to accomplish this.
Firstly, create a model to represent your JSON data. Typically I would capitalize the first letter of the property names here, but to keep it consistent with the JSON, they are lower case.
public class UserData
{
public string name { get; set; }
public string username { get; set; }
public int id { get; set; }
public string state { get; set; }
public string email { get; set; }
}
You will need to add a using for Json.NET
using Newtonsoft.Json;
Finally, you can load, and deserialize your data into a strongly typed list, which you can then use to populate your engineers dictionary.
string datapath = #"D:\project\Gitlap\EngineerEmail\jsonlist5.json";
Dictionary<string, string> engineers = new Dictionary<string, string>();
List<UserData> data = new List<UserData>();
using (StreamReader r = new StreamReader(datapath))
{
string json = r.ReadToEnd();
data = JsonConvert.DeserializeObject<List<UserData>>(json);
data.ForEach(engineer => engineers.Add(engineer.email, engineer.id.ToString()));
}
As mentioned in another answer, your JSON is also badly formed. This will need correcting before it will deserialize correctly. We just need to add a comma to separate the two objects, and wrap them both in a JSON array, with []
[
{
"name":"name1",
"username":"name1",
"id":505,
"state":"active",
"email":"name1#mail.com"
},
{
"name":"name2",
"username":"name2",
"id":504,
"state":"active",
"email":"name2#mail.com"
}
]
Improvements
As your Id field is an integer, it would be better to change your dictionary from
Dictionary<string, string> engineers = new Dictionary<string, string>();
into
Dictionary<string, int> engineers = new Dictionary<int, string>();
You will then be able to simplify your ForEach query slightly. The ForEach can also be moved outside of the using() block.
data.ForEach(engineer =>
engineers.Add(engineer.email, engineer.id));
Improved solution
This includes the improvements above, I've used var for brevity.
var datapath = #"D:\project\Gitlap\EngineerEmail\jsonlist5.json";
var engineers = new Dictionary<string, int>();
var data = new List<UserData>();
using (var r = new StreamReader(datapath))
{
var json = r.ReadToEnd();
data = JsonConvert.DeserializeObject<List<UserData>>(json);
}
data.ForEach(engineer =>
engineers.Add(engineer.email, engineer.id));

try to create class that represent the data in json object for example
Class obj
{
public int Id { get ; set; }
public string email { get ; set; }
public string username { get ; set; }
public string state { get ; set; }
public string email { get ; set; }
}
then
using System.Web.Script.Serialization;
var js = new JavaScriptSerializer();
List<obj> list = js.Deserialize<List<obj>>(jsonString);
after that you can access all list items id and email by using foreach

How do deserialize JSON with non-standard (and varying) property names (in .NET)

I have to read a JSON stream (which I have no control over), which is in the form:
{"files":
{
"/some_file_path.ext": {"size":"1000", "data":"xxx", "data2":"yyy"},
"/other_file_path.ext": {"size":"2000", "data":"xxx", "data2":"yyy"},
"/another_file_path.ext": {"size":"3000", "data":"xxx", "data2":"yyy"},
}
}
So, I have an object named files, which has a number of properties, which have 1) different names every time, 2) different number of them every time, and 3) names with characters which can't be used in C# properties.
How do I deserialize this?
I'm putting this into a Portable Library, so I can't use the JavaScriptSerializer, in System.Web.Script.Serialization, and I'm not sure about JSON.NET. I was hoping to use the standard DataContractJsonSerializer.
UPDATE: I've changed the sample data to be closer to the actual data, and corrected the JSON syntax in the area the wasn't important. (Still simplified quite a bit, but the other parts are fairly standard)

You can model your "files" object as a Dictionary keyed by the JSON property name:
public class RootObject
{
public Dictionary<string, PathData> files { get; set; }
}
public class PathData
{
public int size { get; set; }
public string data { get; set; }
public string data2 { get; set; }
}
Then, only if you are using .Net 4.5 or later, you can deserialize using DataContractJsonSerializer, but you must first set DataContractJsonSerializerSettings.UseSimpleDictionaryFormat = true:
var settings = new DataContractJsonSerializerSettings { UseSimpleDictionaryFormat = true };
var root = DataContractJsonSerializerHelper.GetObject<RootObject>(jsonString, settings);
With the helper method:
public static class DataContractJsonSerializerHelper
{
public static T GetObject<T>(string json, DataContractJsonSerializer serializer = null)
{
using (var stream = GenerateStreamFromString(json))
{
var obj = (serializer ?? new DataContractJsonSerializer(typeof(T))).ReadObject(stream);
return (T)obj;
}
}
public static T GetObject<T>(string json, DataContractJsonSerializerSettings settings)
{
return GetObject<T>(json, new DataContractJsonSerializer(typeof(T), settings));
}
private static MemoryStream GenerateStreamFromString(string value)
{
return new MemoryStream(Encoding.Unicode.GetBytes(value ?? ""));
}
}
Alternatively, you can install Json.NET and do:
var root = JsonConvert.DeserializeObject<RootObject>(jsonString);
Json.NET automatically serializes dictionaries to JSON objects without needing to change settings.

We need to first convert this Invalid JSON to a Valid JSON. So a Valid JSON should look like this
{
"files":
{
"FilePath" : "C:\\some\\file\\path",
"FileData" : {
"size": 1000,
"data": "xxx",
"data2": "yyy"
},
"FilePath" :"C:\\other\\file\\path",
"FileData" : {
"size": 2000,
"data": "xxx",
"data2": "yyy"
},
"FilePath" :"C:\\another\\file\\path",
"FileData" : {
"size": 3000,
"data": "xxx",
"data2": "yyy"
}
}
}
To make it a valid JSON we might use some string functions to make it looks like above. Such as
MyJSON = MyJSON.Replace("\\", "\\\\");
MyJSON = MyJSON.Replace("files", "\"files\"");
MyJSON = MyJSON.Replace("data:", "\"data:\"");
MyJSON = MyJSON.Replace("data2", "\"data2\"");
MyJSON = MyJSON.Replace(": {size", ",\"FileData\" : {\"size\"");
MyJSON = MyJSON.Replace("C:", "\"FilePath\" :\"C:");
Than we can create a class like below to read the
public class FileData
{
public int size { get; set; }
public string data { get; set; }
public string data2 { get; set; }
}
public class Files
{
public string FilePath { get; set; }
public FileData FileData { get; set; }
}
public class RootObject
{
public Files files { get; set; }
}

Assuming you have a valid JSON you could use JavaScriptSerializer to return a list of objects
string json = "{}"
var serializer = new JavaScriptSerializer();
var deserializedValues = (Dictionary<string, object>)serializer.Deserialize(json, typeof(object));
Alternatively you could specify Dictionary<string, List<string>> as the type argument
strign json = "{}";
JavaScriptSerializer serializer = new JavaScriptSerializer();
var deserializedValues = serializer.Deserialize<Dictionary<string, List<string>>>(json);
foreach (KeyValuePair<string, List<string>> kvp in deserializedValues)
{
Console.WriteLine(kvp.Key + ": " + string.Join(",", kvp.Value));
}

convert json String to datatable?

While converting json string datatable facing an issue with , (comma) value in value field.
actualy my json string is [{"BNo":"345","GNo":"3453","FirstName":"fjai","LastName":"ljai","Address":"BARETI,CEVO, 13/2","Telephone":"051682247","BirthDate":"23-Jan-1981","Email":""}]
In that please look at the address scenario "Address":"BARETI,CEVO, 13/2"
It has the , in the values field. While converting the string to data base i got error. Here the code which i used convert json string to datatable
public DataTable JsonStringToDataTbl(string jsonString)
{
DataTable dt = new DataTable();
string[] jsonStringArray = Regex.Split(jsonString.Replace("[", "").Replace("]", ""), "},{");
List<string> ColumnsName = new List<string>();
foreach (string jSA in jsonStringArray)
{
string[] jsonStringData = Regex.Split(jSA.Replace("{", "").Replace("}", ""), ",");
foreach (string ColumnsNameData in jsonStringData)
{
try
{
int idx = ColumnsNameData.IndexOf(":");
string ColumnsNameString = ColumnsNameData.Substring(0, idx - 1).Replace("\"", "");
if (!ColumnsName.Contains(ColumnsNameString))
{
ColumnsName.Add(ColumnsNameString);
}
}
catch (Exception ex)
{
throw new Exception(string.Format("Error Parsing Column Name : {0}", ColumnsNameData));
}
}
break;
}
foreach (string AddColumnName in ColumnsName)
{
dt.Columns.Add(AddColumnName);
}
foreach (string jSA in jsonStringArray)
{
string[] RowData = Regex.Split(jSA.Replace("{", "").Replace("}", ""), ",");
DataRow nr = dt.NewRow();
foreach (string rowData in RowData)
{
try
{
int idx = rowData.IndexOf(":");
string RowColumns = rowData.Substring(0, idx - 1).Replace("\"", "");
string RowDataString = rowData.Substring(idx + 1).Replace("\"", "");
nr[RowColumns] = RowDataString;
}
catch (Exception ex)
{
continue;
}
}
dt.Rows.Add(nr);
}
return dt;
}
The code must omit the , in the value field.. what can i do

If your keys are unknown at the time of being read, then you can use the JObject and the JProperty classes from JSON.Net to retrieve the keys and their values like this:
private void printKeysAndValues(string json)
{
var jobject = (JObject)((JArray)JsonConvert.DeserializeObject(json))[0];
foreach (var jproperty in jobject.Properties())
{
Console.WriteLine("{0} - {1}", jproperty.Name, jproperty.Value);
}
}
Applied to two different JSON input string, retrieves the key/value pair:
var json1 = #"[{""BNo"":""345"",""GNo"":""3453"",""FirstName"":""fjai"",""LastName"":""ljai"",""Address"":""BARETI,CEVO, 13/2"",""Telephone"":""051682247"",""BirthDate"":""23-Jan-1981"",""Email"":""""}]";
var json2 = #"[{""Test"": ""A"", ""Text"":""some text"", ""Numbers"":""123""}]";
printKeysAndValues(json1);
Console.WriteLine("-------------------");
printKeysAndValues(json2);
And the output is:
BNo - 345
GNo - 3453
FirstName - fjai
LastName - ljai
Address - BARETI,CEVO, 13/2
Telephone - 051682247
BirthDate - 23-Jan-1981
Email -
-------------------
Test - A
Text - some text
Numbers - 123
One possibility would be to use the dynamic keyword. You can directly access the field like this:
var json = #"[{""BNo"":""345"",""GNo"":""3453"",""FirstName"":""fjai"",""LastName"":""ljai"",""Address"":""BARETI,CEVO, 13/2"",""Telephone"":""051682247"",""BirthDate"":""23-Jan-1981"",""Email"":""""}]";
dynamic data = JsonConvert.DeserializeObject(json);
// take the first element of the array
string address = data[0].Address;
Console.WriteLine(address.Replace(",", " "));
The output is:
BARETI CEVO 13/2
Note that String.Replace does not fail, if the symbol that should be replaced is not currently present, so "test".Replace(",", " "); will return test.
Another possibility is to use the in ASP.NET build in JSON converter (serializer/deserializer) - NewtonSoft JSON.Net. You can use it in order to regain the structured data. You need to create a class that represents the JSON structure:
public class Data
{
public string BNo { get; set; }
public string GNo { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string Address { get; set; }
public string Telephones { get; set; }
public string BirthDates { get; set; }
public string Emails { get; set; }
}
Then the current JSON can be converted to an object of type Data using the JsonConvert.DeserializeObject method:
var json = #"[{""BNo"":""345"",""GNo"":""3453"",""FirstName"":""fjai"",""LastName"":""ljai"",""Address"":""BARETI,CEVO, 13/2"",""Telephone"":""051682247"",""BirthDate"":""23-Jan-1981"",""Email"":""""}]";
// remove square braces [ and ] at the start resp. end
var data = JsonConvert.DeserializeObject<Data>(json.Substring(1).Substring(0, json.Length - 2));
Now you can access the Address field and for example replace the , symbol:
Console.WriteLine(data.Address.Replace(",", " "));
The output is:
BARETI CEVO 13/2
I think your service returns also the wrong JSON format. JSON always starts with an object (when not in JavaScript), meaning that everything at the top level must be enclosed within curly braces { and }. If the service should return an array, then it should look like this {"results": [{"BNo":"...},{...}]}. If you can't change the service, then you can adapt / correct the returned string. Add a typed model for the array:
public class DataHolder
{
public Data[] data { get; set; }
}
and then create a correct JSON object holding an array:
var data = JsonConvert.DeserializeObject<DataHolder>("{\"data\":" + json + "}");
Console.WriteLine(data.data[0].Address.Replace(",", " "));
The output is again the same.

You can convert the JSON value to C# objects using Newtonsoft. This would be easy for you. Once you have converted to the below object, you can easily modify the Address property to remove the ',' value.
public class RootObject
{
public string BNo { get; set; }
public string GNo { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string Address { get; set; }
public string Telephone { get; set; }
public string BirthDate { get; set; }
public string Email { get; set; }
}
Use the below line to convert to C# object
var jsonString = "The output of your webservice";
var obj = Newtonsoft.Json.JsonConvert.DeserializeObject<RootObject>(jsonString);
Now obj instance holds the C# object which is very easy to manipulate.