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Mapping JSON from Yahoo! Finance API to C# objects [duplicate]

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Deserialize JSON data with C#
(4 answers)
Closed 1 year ago.
I am a student working on a project. I am trying to use the Yahoo! Finance API as a source for my data https://www.yahoofinanceapi.com . I can use HttpWebRequests to call the API and get the "OK" code, see the code below on how I did it:
string BaseURL = "https://yfapi.net/v6/finance/quote?symbols=AAPL";
string addSymbol = "%2C";
string URL = BaseURL;
foreach (string stock in stocks)
{
URL += addSymbol + stock;
}
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URL);
request.Headers.Add("X-API-KEY", "[My API key]");
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Console.WriteLine(response.ContentType);
Console.WriteLine(response.StatusCode);
response.ContentType gives back "application/json".
response.StatusCode gives back "OK".
Since the response is a JSON I tried to parse it into a string using .ToString() but this obviously doesn't work. When I print it, it just says "System.Net.HttpWebResponse" instead of the showing the actual data in the JSON.
After that I tried to deserialize it using newtonsoft
Results result = JsonConvert.DeserializeObject<Results>(request.GetResponse().ToString());
where Results is a class I made where there is a list of stocks, Stock is also a class I made with some variables in it with the same names of variables in the JSON response.
I got a JSON response from PostMan when I tested the API, opened the response to see what kind of data it contained.
When I ran my code I got the following error message:
Newtonsoft.Json.JsonReaderException: 'Unexpected character encountered while parsing value: S. Path '', line 0, position 0.'
This was as far as I got, I tested a few other methods trying to get this working but this one worked the "best".
My biggest issue at the moment is mapping the response into a c# object.
Anything that can help me understand is appreciated :D

You're trying to serialise the HttpWebResponse object into Results, which means deserialisation won't work.
The data is still wrapped & won't be in the format of the Results object.
The GetResponseStream() method can be used to get the contents of the HTTP response as a stream, which can then be deserialised directly, in this case, using Json.NET.
Replace this section:
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Console.WriteLine(response.ContentType);
Console.WriteLine(response.StatusCode);
With this:
var serializer = new JsonSerializer();
using (var response = (HttpWebResponse)request.GetResponse())
{
var encoding = Encoding.GetEncoding(response.CharacterSet);
using var responseStream = response.GetResponseStream();
using var reader = new StreamReader(responseStream, encoding);
using (var jsonTextReader = new JsonTextReader(reader))
{
Console.WriteLine(response.ContentType);
Console.WriteLine(response.StatusCode);
Results result = serializer.Deserialize<Results>(jsonTextReader);
}
}
Alternatively, a much better solution if you're using .NET 4.5 <= would be to use HttpClient like below:
private static readonly HttpClient httpClient = new HttpClient();
...
string BaseURL = "https://yfapi.net/v6/finance/quote?symbols=AAPL";
string addSymbol = "%2C";
string URL = BaseURL;
foreach(string stock in stocks) {
URL += addSymbol + stock;
}
client.DefaultRequestHeaders.Add("X-API-KEY", "[My API key]");
var data = await httpClient.GetStringAsync(address);
Results result = JsonConvert.DeserializeObject<Results>(data);

C# eBay Listing Recommendation API

I'm having trouble getting any type of response from the Listing Recommendation API. I keep getting a generic 500 message on my return. I've set up my headers the way they recommend here: https://developer.ebay.com/devzone/listing-recommendation/Concepts/MakingACall.html
I've tried using the information from the documentation on the call here: https://developer.ebay.com/devzone/listing-recommendation/CallRef/itemRecommendations.html#Samples
But every variation of my code comes up bad. Below is a sample of the code. I've tried it with and without the commented out line of code with the same results. It always fails on the line response.GetResponseStream. Thanks for your help.
public static void test(string AuthToken, string listing, log4net.ILog log)
{
string url = "https://svcs.ebay.com/services/selling/listingrecommendation/v1/item/" + listing + "/itemRecommendations/?recommendationType=ItemSpecifics";
var listingRecommendationRequest = (HttpWebRequest)WebRequest.Create(url);
listingRecommendationRequest.Headers.Add("Authorization", "TOKEN " + AuthToken);
listingRecommendationRequest.ContentType = "application/json";
listingRecommendationRequest.Accept = "application/json";
listingRecommendationRequest.Headers.Add("X-EBAY-GLOBAL-ID", "EBAY-US");
listingRecommendationRequest.Method = "GET";
//listingRecommendationRequest.Headers.Add("recommendationType", "ItemSpecifics");
var response = (HttpWebResponse)listingRecommendationRequest.GetResponse();
string result;
using (var streamReader = new StreamReader(response.GetResponseStream()))
{
result = streamReader.ReadToEnd();
}
var reader = new JsonTextReader(new StringReader(result));
while (reader.Read())
{
if (reader.Value != null)
{
// Read Json values here
var pt = reader.Path;
var val = reader.Value.ToString();
}
}
}
Edit: Adding image of what I'm trying to accomplish. I'm trying to get the item specifics recommendations that are suggested by eBay when manually editing a listing. These suggestions change based on what is in your title.

Substring a HTTP Response into a Variable [C# Winforms]

Im trying to get a cryptocurrency last price value from a HTTP API:
The following piece of code:
// Create the web request
HttpWebRequest request =
WebRequest.Create("APISITE") as
HttpWebRequest;
// Get response
using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
{
// Get the response stream
StreamReader reader = new StreamReader(response.GetResponseStream());
// Console application output
currentXRPPrice.Text = (reader.ReadToEnd());
}
Gives me the following response which is correct:
{"high": "1.15600", "last": "1.08269", "timestamp": "1518697359", "bid": "1.08034", "vwap": "1.09634", "volume": "40858340.75727354", "low": "1.03051", "ask": "1.08269", "open": "1.13489"}
What I want is just the value of "last" which is "1.08269".
I have tried using this post: [link] (Remove characters after specific character in string, then remove substring?)
which has worked wonders for me on previous projects. But I cant seem to figure out where I am going wrong.
Iv tried below to get the value of "last" but its completely wrong, I have tried many of the different combinations to get it right but its not working to show me just the value for "Last".
response = currentXRPPrice.Text;
response = response.Remove(response.LastIndexOf(":") + 1);
profitLossText.Text = response; //Still wrong tried 4 combinations none work.
Thanks for any help!

You need to install Newtonsoft.Json from Nuget packages and use Parse method from JObject:
var lastValue = JObject.Parse(currentXRPPrice.Text).SelectToken("last").ToString();

First of all, if you have Json string, you can define a class which represent this object and then you just deserialize this string to object using generic method.
var jsonString = currentXRPPrice.Text;
var deserializedResponse = JsonConvert.DeserializeObject<ReponseType>(jsonString);
var lastValue = deserializedResponse.Last;
public class ReponseType
{
...
public float Last { get; set; }
...
}
You can do it by Regex too:
var lastValue = Regex.Match(jsonString, #"last\": \"(\\d+\\.\\d+)"").Groups[0];

send list<xmldocument> to wcf, how to do it?

I'm trying to send List to wcf.
i want to send it as json, is there a way ?
when I'm trying to serialize, i get empty string, why ?
public string ImportXml(List<XmlDocument> docs,string token)
{
Account user = GetCurrentUser(token);
string url = string.Format("{0}ImportXml/{1}", ServiceUrl, user.Unumber);
string contentType = "text/json";
x.Serialize(Console.Out, docs);
string jsonReq = _serializer.Serialize(docs);
bool response = false;
HttpRequestHandler handler = new HttpRequestHandler();
string result = handler.HttpPostWithToken(url, jsonReq, contentType, token);
return result ;
}

Each element of the collection docs before sending into WCF is must be serialized into the JSON for example in this way:
string jsonText = JsonConvert.SerializeXmlNode(doc);
where doc is XmlDocument.
Or for Javascript in this way: Converting between XML and JSON
After you get collection of XmlDocument into WCF method try convert each element of entrance collection:
var documents = new List<XmlDocument>();
foreach (var doc in docs)
{
XmlDocument xmlDoc = JsonConvert.DeserializeXmlNode(doc);
documents.Add(xmlDoc);
}

finnally i got list of strings with xml in it.
it is much better, because that way we can work with anyone, and not only C#.
and i moved to newtonsoft instead JSS.
List<string>

using dynamic keyword when parse JSON

I'm newbie to using the dynamic keyword in C#. It seems simple enough, but I can't seem to use it effectively.
I see this example from Facebook:
var client = new FacebookClient();
dynamic me = client.Get("totten");
string firstname = me.first_name;
it works fine, but if you look at me in a debugger, then you can see that client.Get() returns simple JSON. The same it's said in Facebook documentation:
The result of this request is a dynamic object containing various
properties such as first_name, last_name, user name, etc. You can see
the values of this request by browsing to
http://graph.facebook.com/totten in your web browser. The JSON result
is shown below.
I want to do the same dodge with returned JSON from Foursquare:
private static string GetReturnedUrlFromHttp(string url)
{
HttpWebRequest webRequest = WebRequest.Create(url) as HttpWebRequest;
webRequest.Timeout = 10000;
webRequest.Method = "GET";
WebResponse response = webRequest.GetResponse();
string responseStr = String.Empty;
using (var stream = response.GetResponseStream())
{
var r = new StreamReader(stream);
responseStr = r.ReadToEnd();
}
return responseStr;
}
public static void FillDataFromFoursquareUsingDynamic()
{
string foursquare_url_detail = "https://api.foursquare.com/v2/venues/4b80718df964a520e57230e3?locale=en&client_id=XXX&client_secret=YYY&v=10102013";
dynamic responseStr = GetReturnedUrlFromHttp(foursquare_url_detail);
var response = responseStr.response;
}
I got the following error:
'string' does not contain a definition for 'response'
Why am I getting this error and is it possible to 'parse' any JSON string like in Facebook?

FacebookClient.Get doesn't really return the JSON string. Instead it parses the string into a dynamic object with properties matching the names of the values in the JSON string.
Using dynamic doesn't magically turn a string into an object with the properties defined in the string. Instead, you need to first parse the string with the help of a JSON library like JSON.NET.