Develop Reference

Get number from API and put it in a variable

I want to get the price value which is usd in this api and put it in a variable:
https://api.coingecko.com/api/v3/simple/price?ids=veco&vs_currencies=usd
I already tried this code but getting an error:
public static void StartGet()
{
HttpWebRequest WebReq = (HttpWebRequest)WebRequest.Create(string.Format(VECO.VecoPriceURL));
WebReq.Method = "GET";
HttpWebResponse WebResp = (HttpWebResponse)WebReq.GetResponse();
string jsonString;
using (Stream stream = WebResp.GetResponseStream())
{
StreamReader reader = new StreamReader(stream, System.Text.Encoding.UTF8);
jsonString = reader.ReadToEnd();
}
List<VECO.Coin> items = JsonConvert.DeserializeObject<List<VECO.Coin>>(jsonString);
foreach (var item in items)
{
Console.WriteLine(item.usd);
}
}
public class VECO
{
public static string VecoPriceURL = "https://api.coingecko.com/api/v3/simple/price?ids=veco&vs_currencies=usd";
public class Coin
{
public string usd { get; set; }
}
}
ERROR:
Newtonsoft.Json.JsonSerializationException: 'Cannot deserialize the current
JSON object (e.g. {"name":"value"}) into type
'System.Collections.Generic.List`1[ConsoleProgram.VECO+Coin]' 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<T>)
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 'veco', line 1, position 8.'

Your Data Structures needs to be slightly different.
public class Veco
{
public decimal usd { get; set; }
}
public class RootObject
{
public Veco veco { get; set; }
}
Please note that Json is a not an array or List, so you need to need List<> in the JsonConvert.DeserializeObject Method as well. Instead, you need to the following.
var result = JsonConvert.DeserializeObject<RootObject>(jsonString);
Example,
var jsonString = #"{'veco':{'usd':0.01558532}}";
var result = JsonConvert.DeserializeObject<RootObject>(jsonString);
Console.WriteLine($"USD Rate : {result.veco.usd}");
Output
USD Rate 0.01558532
Rewriting your method,
public static void StartGet()
{
HttpWebRequest WebReq = (HttpWebRequest)WebRequest.Create(string.Format(VECO.VecoPriceURL));
WebReq.Method = "GET";
HttpWebResponse WebResp = (HttpWebResponse)WebReq.GetResponse();
string jsonString;
using (Stream stream = WebResp.GetResponseStream())
{
StreamReader reader = new StreamReader(stream, System.Text.Encoding.UTF8);
jsonString = reader.ReadToEnd();
}
var item = JsonConvert.DeserializeObject<RootObject>(jsonString);
Console.WriteLine(item.veco.usd);
}
Update
Based on your comment, I would rewrite your method as follows. You no longer need the data structure.
public static void StartGet(string id)
{
var url = $"https://api.coingecko.com/api/v3/simple/price?ids={id}&vs_currencies=usd";
HttpWebRequest WebReq = (HttpWebRequest)WebRequest.Create(url);
WebReq.Method = "GET";
HttpWebResponse WebResp = (HttpWebResponse)WebReq.GetResponse();
string jsonString;
using (Stream stream = WebResp.GetResponseStream())
{
StreamReader reader = new StreamReader(stream, System.Text.Encoding.UTF8);
jsonString = reader.ReadToEnd();
}
var result = JsonConvert.DeserializeObject<JToken>(jsonString);
Console.WriteLine($"For {id},USD Rate : {result[id].Value<string>("usd")}");
}
Now you can use the method as follows
StartGet("veco");
StartGet("eos");
StartGet("uraniumx");
Output
For veco,USD Rate : 0.01581513
For eos,USD Rate : 2.42
For uraniumx,USD Rate : 0.890397

String to JSON to 2D Array C#

I am receiving response from httpWebRequest as a string, which is format of JSON. What I would like, is to change this string to json and then, there are two opitons
1) change json to the 2D array
2) change json to dictionary
The point is I want to have easy access to the variables.
This is a string I am receiving:
"[{\"Year\":2000,\"Name\":\"Ala\",\"Val\":0.5},{\"Year\":2001,\"Name\":\"Ola\",\"Val\":0.6}... {\"Year\":2004,\"Name\":\"Ela\",\"Val\":0.8}]"
So as you can see I could have table with n rows and 3 columns (Year, Name, Val).
This is the code which I use to receive the response
var httpWebRequest = (HttpWebRequest)WebRequest.Create("http://127.0.0.1:5000/");
httpWebRequest.ContentType = "application/json";
httpWebRequest.Method = "POST";
using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
{
//send request data in json format
streamWriter.Write(jsonData);
}
var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
{
//take data as string
var result = streamReader.ReadToEnd();
}
return null;
}
Instead of null I will return this array/dictionary.
Which way is better? Someone know how to make it? I feel lost in c#.
Thank you for help in advance!

First, to make work with JSON easier you can install Newtonsoft.Json package
Install-Package Newtonsoft.Json -Version 11.0.2
Then add using Newtonsoft.Json;
Look at this example
public class Item
{
public int Year { get; set; }
public string Name { get; set; }
public double Val { get; set; }
}
public class Program
{
public static void Main()
{
string json = "[{\"Year\":2000,\"Name\":\"Ala\",\"Val\":0.5},{\"Year\":2001,\"Name\":\"Ola\",\"Val\":0.6},{\"Year\":2004,\"Name\":\"Ela\",\"Val\":0.8}]";
List<Item> items = JsonConvert.DeserializeObject<List<Item>>(json);
foreach(var item in items)
{
Console.WriteLine("Year: {0}; Name: {1}; Val: {2}", item.Year, item.Name, item.Val);
}
}
}
Here I create a new class Item witch will be represents one object from array from your JSON. Then using Newtonsoft.Json deserialize json string to list of items.

JSON Numeric Keys

Sorry for asking this question again, but I just don't seem to understand the given answers :(
I need to read some JSON using JSON.net. some of the keys start with numbers, eg.
"24h_rate":22.65826595,"
When I put the JSON into http://json2csharp.com/ to make my classes, it makes it into __invalid_name__24h_total.
I am using the following to read and Deserialize the JSON
public class JsonWebClient
{
public async Task<System.IO.TextReader> DoRequestAsync(WebRequest req)
{
var task = Task.Factory.FromAsync((cb, o) => ((HttpWebRequest)o).BeginGetResponse(cb, o), res => ((HttpWebRequest)res.AsyncState).EndGetResponse(res), req);
var result = await task;
var resp = result;
var stream = resp.GetResponseStream();
var sr = new System.IO.StreamReader(stream);
return sr;
}
public async Task<T> getJsonAsync<T>(string url)
{
HttpWebRequest req = HttpWebRequest.CreateHttp(url);
req.AllowReadStreamBuffering = true;
var ret = await DoRequestAsync(req);
var response = await ret.ReadToEndAsync();
return Newtonsoft.Json.JsonConvert.DeserializeObject<T>(response);
}
}
What do I need to change to make this work?
Thanks very much.

Playing around with it a bit I found out that the deserializer you're using can't 'handle' key names that start with a number for some reason, even though it's perfectly valid JSON (checked with http://jsonlint.com/)
If you change it to this instead
{ "rate_24h":22.65826595 }
it works:
public class RootObject
{
public double rate_24h { get; set; }
}
Thanks to #Ulugbek Umirov:
Your rate_24h property should be attributed with [JsonProperty("24h_rate")] to be property deserialized by JSON.NET.

Convert JSON String To C# Object

Trying to convert a JSON string into an object in C#. Using a really simple test case:
JavaScriptSerializer json_serializer = new JavaScriptSerializer();
object routes_list = json_serializer.DeserializeObject("{ \"test\":\"some data\" }");
The problem is that routes_list never gets set; it's an undefined object. Any ideas?

Or, you can use the Newtownsoft.Json library as follows:
using Newtonsoft.Json;
...
var result = JsonConvert.DeserializeObject<T>(json);
Where T is your object type that matches your JSON string.

It looks like you're trying to deserialize to a raw object. You could create a Class that represents the object that you're converting to. This would be most useful in cases where you're dealing with larger objects or JSON Strings.
For instance:
class Test {
String test;
String getTest() { return test; }
void setTest(String test) { this.test = test; }
}
Then your deserialization code would be:
JavaScriptSerializer json_serializer = new JavaScriptSerializer();
Test routes_list =
(Test)json_serializer.DeserializeObject("{ \"test\":\"some data\" }");
More information can be found in this tutorial:
http://www.codeproject.com/Tips/79435/Deserialize-JSON-with-Csharp.aspx

You probably don't want to just declare routes_list as an object type. It doesn't have a .test property, so you really aren't going to get a nice object back. This is one of those places where you would be better off defining a class or a struct, or make use of the dynamic keyword.
If you really want this code to work as you have it, you'll need to know that the object returned by DeserializeObject is a generic dictionary of string,object. Here's the code to do it that way:
var json_serializer = new JavaScriptSerializer();
var routes_list = (IDictionary<string, object>)json_serializer.DeserializeObject("{ \"test\":\"some data\" }");
Console.WriteLine(routes_list["test"]);
If you want to use the dynamic keyword, you can read how here.
If you declare a class or struct, you can call Deserialize instead of DeserializeObject like so:
class MyProgram {
struct MyObj {
public string test { get; set; }
}
static void Main(string[] args) {
var json_serializer = new JavaScriptSerializer();
MyObj routes_list = json_serializer.Deserialize<MyObj>("{ \"test\":\"some data\" }");
Console.WriteLine(routes_list.test);
Console.WriteLine("Done...");
Console.ReadKey(true);
}
}

Using dynamic object with JavaScriptSerializer.
JavaScriptSerializer serializer = new JavaScriptSerializer();
dynamic item = serializer.Deserialize<object>("{ \"test\":\"some data\" }");
string test= item["test"];
//test Result = "some data"

Newtonsoft is faster than java script serializer. ... this one depends on the Newtonsoft NuGet package, which is popular and better than the default serializer.
one line code solution.
var myclass = Newtonsoft.Json.JsonConvert.DeserializeObject<dynamic>(Jsonstring);
Myclass oMyclass = Newtonsoft.Json.JsonConvert.DeserializeObject<Myclass>(Jsonstring);

You can accomplished your requirement easily by using Newtonsoft.Json library. I am writing down the one example below have a look into it.
Class for the type of object you receive:
public class User
{
public int ID { get; set; }
public string Name { get; set; }
}
Code:
static void Main(string[] args)
{
string json = "{\"ID\": 1, \"Name\": \"Abdullah\"}";
User user = JsonConvert.DeserializeObject<User>(json);
Console.ReadKey();
}
this is a very simple way to parse your json.

Here's a simple class I cobbled together from various posts.... It's been tested for about 15 minutes, but seems to work for my purposes. It uses JavascriptSerializer to do the work, which can be referenced in your app using the info detailed in this post.
The below code can be run in LinqPad to test it out by:
Right clicking on your script tab in LinqPad, and choosing "Query
Properties"
Referencing the "System.Web.Extensions.dll" in "Additional References"
Adding an "Additional Namespace Imports" of
"System.Web.Script.Serialization".
Hope it helps!
void Main()
{
string json = #"
{
'glossary':
{
'title': 'example glossary',
'GlossDiv':
{
'title': 'S',
'GlossList':
{
'GlossEntry':
{
'ID': 'SGML',
'ItemNumber': 2,
'SortAs': 'SGML',
'GlossTerm': 'Standard Generalized Markup Language',
'Acronym': 'SGML',
'Abbrev': 'ISO 8879:1986',
'GlossDef':
{
'para': 'A meta-markup language, used to create markup languages such as DocBook.',
'GlossSeeAlso': ['GML', 'XML']
},
'GlossSee': 'markup'
}
}
}
}
}
";
var d = new JsonDeserializer(json);
d.GetString("glossary.title").Dump();
d.GetString("glossary.GlossDiv.title").Dump();
d.GetString("glossary.GlossDiv.GlossList.GlossEntry.ID").Dump();
d.GetInt("glossary.GlossDiv.GlossList.GlossEntry.ItemNumber").Dump();
d.GetObject("glossary.GlossDiv.GlossList.GlossEntry.GlossDef").Dump();
d.GetObject("glossary.GlossDiv.GlossList.GlossEntry.GlossDef.GlossSeeAlso").Dump();
d.GetObject("Some Path That Doesnt Exist.Or.Another").Dump();
}
// Define other methods and classes here
public class JsonDeserializer
{
private IDictionary<string, object> jsonData { get; set; }
public JsonDeserializer(string json)
{
var json_serializer = new JavaScriptSerializer();
jsonData = (IDictionary<string, object>)json_serializer.DeserializeObject(json);
}
public string GetString(string path)
{
return (string) GetObject(path);
}
public int? GetInt(string path)
{
int? result = null;
object o = GetObject(path);
if (o == null)
{
return result;
}
if (o is string)
{
result = Int32.Parse((string)o);
}
else
{
result = (Int32) o;
}
return result;
}
public object GetObject(string path)
{
object result = null;
var curr = jsonData;
var paths = path.Split('.');
var pathCount = paths.Count();
try
{
for (int i = 0; i < pathCount; i++)
{
var key = paths[i];
if (i == (pathCount - 1))
{
result = curr[key];
}
else
{
curr = (IDictionary<string, object>)curr[key];
}
}
}
catch
{
// Probably means an invalid path (ie object doesn't exist)
}
return result;
}
}

As tripletdad99 said
var result = JsonConvert.DeserializeObject<T>(json);
but if you don't want to create an extra object you can make it with Dictionary instead
var result = JsonConvert.DeserializeObject<Dictionary<string, string>>(json_serializer);

add this ddl to reference to your project: System.Web.Extensions.dll
use this namespace: using System.Web.Script.Serialization;
public class IdName
{
public int Id { get; set; }
public string Name { get; set; }
}
string jsonStringSingle = "{'Id': 1, 'Name':'Thulasi Ram.S'}".Replace("'", "\"");
var entity = new JavaScriptSerializer().Deserialize<IdName>(jsonStringSingle);
string jsonStringCollection = "[{'Id': 2, 'Name':'Thulasi Ram.S'},{'Id': 2, 'Name':'Raja Ram.S'},{'Id': 3, 'Name':'Ram.S'}]".Replace("'", "\"");
var collection = new JavaScriptSerializer().Deserialize<IEnumerable<IdName>>(jsonStringCollection);

Copy your Json and paste at textbox on json2csharp and click on Generate button.
A cs class will be generated use that cs file as below
var generatedcsResponce = JsonConvert.DeserializeObject(yourJson);
Where RootObject is the name of the generated cs file;

Another fast and easy way to semi-automate these steps is to:
take the JSON you want to parse and paste it here: https://app.quicktype.io/ . Change language to C# in the drop down.
Update the name in the top left to your class name, it defaults to "Welcome".
In visual studio go to Website -> Manage Packages and use NuGet to add Json.Net from Newtonsoft.
app.quicktype.io generated serialize methods based on Newtonsoft.
Alternatively, you can now use code like:
WebClient client = new WebClient();
string myJSON = client.DownloadString("https://URL_FOR_JSON.com/JSON_STUFF");
var myClass = Newtonsoft.Json.JsonConvert.DeserializeObject(myJSON);

Convert a JSON string into an object in C#. Using below test case.. its worked for me. Here "MenuInfo" is my C# class object.
JsonTextReader reader = null;
try
{
WebClient webClient = new WebClient();
JObject result = JObject.Parse(webClient.DownloadString("YOUR URL"));
reader = new JsonTextReader(new System.IO.StringReader(result.ToString()));
reader.SupportMultipleContent = true;
}
catch(Exception)
{}
JsonSerializer serializer = new JsonSerializer();
MenuInfo menuInfo = serializer.Deserialize<MenuInfo>(reader);

First you have to include library like:
using System.Runtime.Serialization.Json;
DataContractJsonSerializer desc = new DataContractJsonSerializer(typeof(BlogSite));
string json = "{\"Description\":\"Share knowledge\",\"Name\":\"zahid\"}";
using (var ms = new MemoryStream(ASCIIEncoding.ASCII.GetBytes(json)))
{
BlogSite b = (BlogSite)desc.ReadObject(ms);
Console.WriteLine(b.Name);
Console.WriteLine(b.Description);
}

Let's assume you have a class name Student it has following fields and it has a method which will take JSON as a input and return a string Student Object.We can use JavaScriptSerializer here Convert JSON String To C# Object.std is a JSON string here.
public class Student
{
public string FirstName {get;set:}
public string LastName {get;set:}
public int[] Grades {get;set:}
}
public static Student ConvertToStudent(string std)
{
var serializer = new JavaScriptSerializer();
Return serializer.Deserialize<Student>(std);
}

Or, you can use the System.Text.Json library as follows:
using System.Text.Json;
...
var options = new JsonSerializerOptions()
{
PropertyNameCaseInsensitive = true
});
var result = JsonSerializer.Deserialize<List<T>>(json, options);
Where T is your object type that matches your JSON string.
System.Text.Json is available in:
.NET Core 2.0 and above
.NET Framework 4.6.1 and above

JSON Twitter List in C#.net

My code is below. I am not able to extract the 'name' and 'query' lists
from the JSON via a DataContracted Class (below)
I have spent a long time trying to work this one out, and could really do
with some help...
My Json string:
{"as_of":1266853488,"trends":{"2010-02-22
15:44:48":[{"name":"#nowplaying","query":"#nowplaying"},{"name":"#musicmonday","query":"#musicmonday"},{"name":"#WeGoTogetherLike","query":"#WeGoTogetherLike"},{"name":"#imcurious","query":"#imcurious"},{"name":"#mm","query":"#mm"},{"name":"#HumanoidCityTour","query":"#HumanoidCityTour"},{"name":"#awesomeindianthings","query":"#awesomeindianthings"},{"name":"#officeformac","query":"#officeformac"},{"name":"Justin
Bieber","query":"\"Justin Bieber\""},{"name":"National
Margarita","query":"\"National Margarita\""}]}}
My code:
WebClient wc = new WebClient();
wc.Credentials = new NetworkCredential(this.Auth.UserName, this.Auth.Password);
string res = wc.DownloadString(new Uri(link));
//the download string gives me the above JSON string - no problems
Trends trends = new Trends();
Trends obj = Deserialise<Trends>(res);
private T Deserialise<T>(string json)
{
T obj = Activator.CreateInstance<T>();
using (MemoryStream ms = new MemoryStream(Encoding.Unicode.GetBytes(json)))
{
DataContractJsonSerializer serialiser = new DataContractJsonSerializer(obj.GetType());
obj = (T)serialiser.ReadObject(ms);
ms.Close();
return obj;
}
}
[DataContract]
public class Trends
{
[DataMember(Name = "as_of")]
public string AsOf { get; set; }
//The As_OF value is returned - But how do I get the
//multidimensional array of Names and Queries from the JSON here?
}

I've run into this very issue while developing Twitterizer. The issue is that the dataset isn't in a traditional object-oriented design.
If you were to map that as objects, you would see:
object root
int as_of
object trends
array[object] <date value of as_of>
string query
string name
As you can see, the trend object has a property that's name changes. The name is based on the as_of date value. As such, it can't be automatically deserialized.
My first solution was to use System.Web.Script.Serialization.JavaScriptSerializer.DeserializeObject(). That method returns a hierarchy of weakly typed, nested dictionary instances. I then stepped through the results myself.
internal static TwitterTrendTimeframe ConvertWeakTrend(object value)
{
Dictionary<string, object> valueDictionary = (Dictionary<string, object>)value;
DateTime date = new DateTime(1970, 1, 1, 0, 0, 0).AddSeconds((int)valueDictionary["as_of"]);
object[] trends = (object[])((Dictionary<string, object>)valueDictionary["trends"])[date.ToString("yyyy-MM-dd HH:mm:ss")];
TwitterTrendTimeframe convertedResult = new TwitterTrendTimeframe()
{
EffectiveDate = date,
Trends = new Collection<TwitterTrend>()
};
for (int i = 0; i < trends.Length; i++)
{
Dictionary<string, object> item = (Dictionary<string, object>)trends[i];
TwitterTrend trend = new TwitterTrend()
{
Name = (string)item["name"]
};
if (item.ContainsKey("url"))
{
trend.Address = (string)item["url"];
}
if (item.ContainsKey("query"))
{
trend.SearchQuery = (string)item["query"];
}
convertedResult.Trends.Add(trend);
}
return convertedResult;
}
It's ugly, but it worked.
I've since embraced the use of Json.NET for it's speed and simplicity.

have you considered using JSON.net ?

Consider this example:
public struct TwitterResponse
{
public int32 as_of;
public Trend[] Trends;
}
public struct Trends
{
public String name;
public String query;
}
Trend[] obj = JavaScriptConvert.DeserializeObject<TwitterResponse>( res ).Trends;
Probably needs finetuning, but that's the general idea on how to do it.