I am trying to access a simple REST Api, https://api.cryptonator.com/api/ticker/btc-usd
The result of the same is like this format:
{"ticker":{"base":"BTC","target":"USD","price":"9969.76308171","volume":"127575.47420967","change":"-197.36472278"},"timestamp":1517410741,"success":true,"error":""}
Now, when I am trying to get result from it, I find ticker objet of json null, timestamp and error objects are getting filled.
So, I suspect there might be the problem datamembers are not matching with json text. My Modeldto looks like this:
public class CurtoUsd
{
public ticker tick { get; set; }
public Single timestamp { get; set; }
public bool success { get; set; }
public string error { get; set; }
}
public class ticker
{
public string _base { get; set; }
public string target { get; set; }
public string price { get; set; }
public string volume { get; set; }
public string change { get; set; }
}
Please have a look, I was suppose to use base as variable but it is the keyword, so instead i used _base.
And I am using httpclient to in asp.net core 2.0 webapi and the code looks like this:
HttpClient client = new HttpClient();
if (client.BaseAddress == null)
{
client.BaseAddress = new Uri("https://api.cryptonator.com/");
}
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
HttpResponseMessage response = await client.GetAsync(baseUrl);
CurtoUsd usdrate = new CurtoUsd();
if (response.IsSuccessStatusCode)
{
usdrate = await response.Content.ReadAsJsonAsync<CurtoUsd>();
}
return CommonFunctions.ConvertDouble(usdrate.tick.price);
Detail
of function:
public static class HttpContentExtensions
{
public static async Task<T> ReadAsJsonAsync<T>(this HttpContent content)
{
string json = await content.ReadAsStringAsync();
T value = JsonConvert.DeserializeObject<T>(json);
return value;
}
}
May I know what's wrong I am doing? Is the point I have pointed out correct, is there any solution if it is so.
Please help.
You can use # in C# to use keywords as identifiers, e.g. foo.#base.#class.
So your DTO becomes:
public class Ticker
{
public string #base { get; set; } // Escape the `base` keyword with `#`
public string target { get; set; }
public string price { get; set; }
public string volume { get; set; }
public string change { get; set; }
}
Note that you should use PascalCase for type identifiers n C#/.NET (so class Ticker instead of class ticker), and for public members too.
Note that Newtonsoft.Json is actually case-insensitive for member names by default (unless you specifically configure it otherwise) so you can use PascalCase for the properties, this also stops them from being C# keywords too, and it will still work:
public class Ticker
{
public string Base { get; set; } // `Base` is not a keyword
public string Target { get; set; }
public string Price { get; set; }
public string Volume { get; set; }
public string Change { get; set; }
}
Related
I'm looking to parse this JSON and I've had nothing but problems. The link to the JSON is here. I'm trying to access the "href" field. While writing this up, I realized that that the data field is actually an array so that is part of my problem.
class Program
{
static void Main(string[] args)
{
var json = System.IO.File.ReadAllText(#"C:\Users\...\file.json");
Root myDeserializedClass = JsonConvert.DeserializeObject<Root>(json);
var x = myDeserializedClass.result.extractorData.data;
Console.Write(x.ToString());
}
public class Newcolumn
{
public string text { get; set; }
public string xpath { get; set; }
public string href { get; set; }
public string filepath { get; set; }
public string fileMimeType { get; set; }
public int fileTotalBytes { get; set; }
public string fileLastModifiedTime { get; set; }
}
public class Group
{
public List<Newcolumn> Newcolumn { get; set; }
}
public class Datum
{
public List<Group> group { get; set; }
}
public class ExtractorData
{
public string url { get; set; }
public List<Datum> data { get; set; }
}
public class PageData
{
public int statusCode { get; set; }
public long timestamp { get; set; }
}
public class Inputs
{
public string _url { get; set; }
}
public class Result
{
public ExtractorData extractorData { get; set; }
public PageData pageData { get; set; }
public Inputs inputs { get; set; }
public string taskId { get; set; }
public long timestamp { get; set; }
public int sequenceNumber { get; set; }
}
public class Root
{
public string url { get; set; }
public Result result { get; set; }
}
}
This ends up returning: System.Collections.Generic.List`1[ConsoleApp3.Datum]
I notice that the field name data actually turns into an array though I'm not sure how to structure that. data.[0].new Column.[0].group.etc... does not work obviously. The space in the "new Column" field is also problematic. Additionally, when I debug and look at the JSON viewer, the "new column field is null. I also tried this code:
public static void Main()
{
var json = System.IO.File.ReadAllText(#"C:\Users\...\file.json");
dynamic stuff = JsonConvert.DeserializeObject(json);
var a = stuff.result.extractorData.data;
string b = a.ToString();
Console.WriteLine(b);
Console.WriteLine("Press any key to exit.");
System.Console.ReadKey();
}
This actually does return the data field object however, if I do stuff.result.extractorData.data.group; I get this:
Microsoft.CSharp.RuntimeBinder.RuntimeBinderException
HResult=0x80131500
Message='Newtonsoft.Json.Linq.JArray' does not contain a definition for 'group'
Source=<Cannot evaluate the exception source>
StackTrace:
<Cannot evaluate the exception stack trace>
I assume that this is probably because of the array contained within the data field, regardless the "new Column' field is also an issue with this method due to the space.
in your above code
public class ExtractorData
{
public string url { get; set; }
public List<Datum> data { get; set; }
}
where data is List and you are trying to access as string
Console.Write(x.ToString());
in data variable Datum is List ( where your variable have multiple Data) and in every element there is a List. (Nestest List Concept Applied in This JSON)
Try to Add Break Point on below Line and check the line by line Excution of Code.
var a = stuff.result.extractorData.data;
After Looking Your JSON File Image Try This Code
Console.Write(a.FirstOrDefault()?.group.FirstOrDefault()?.Newcolumn.FirstOrDefault()?.href);
I am creating a UWP app, simply put I have an async void GetWeather function that reads JSON from an API and creates an object. Calling the Forecast.getWeather() function I get the error " object reference required from non-static method". I have done my research but have not found a solution to this with a void method as I don't want to return an object just yet. Also if this is not possible (and maybe a better idea) how would I return the Object so it can be used on many different pages throughout the app or would the object values still be accessible if created in the void method?
Forecast.cs
class Forecast
{
public async void GetWeather()
{
var uri = new Uri("MY API URI HERE");
using (HttpClient client = new HttpClient())
{
using (HttpResponseMessage response = await client.GetAsync(uri))
{
using (IHttpContent content = response.Content)
{
var json = await content.ReadAsStringAsync();
var result = JsonConvert.DeserializeObject<RootObject>(json);
Debug.WriteLine("In async method");
}
}
}
}
}
MainPage
public sealed partial class MainPage : Page
{
public MainPage()
{
this.InitializeComponent();
Forecast.GetWeather();
}
}
Weather.cs
namespace WeatherForecast
{
public class Main
{
public double temp { get; set; }
public double temp_min { get; set; }
public double temp_max { get; set; }
public double pressure { get; set; }
public double sea_level { get; set; }
public double grnd_level { get; set; }
public int humidity { get; set; }
public double temp_kf { get; set; }
}
public class Weather
{
public int id { get; set; }
public string main { get; set; }
public string description { get; set; }
public string icon { get; set; }
}
public class Clouds
{
public int all { get; set; }
}
public class Wind
{
public double speed { get; set; }
public double deg { get; set; }
}
public class Snow
{
public double __invalid_name__3h { get; set; }
}
public class Sys
{
public string pod { get; set; }
}
public class List
{
public int dt { get; set; }
public Main main { get; set; }
public List<Weather> weather { get; set; }
public Clouds clouds { get; set; }
public Wind wind { get; set; }
public Snow snow { get; set; }
public Sys sys { get; set; }
public string dt_txt { get; set; }
}
public class Coord
{
public double lat { get; set; }
public double lon { get; set; }
}
public class City
{
public int id { get; set; }
public string name { get; set; }
public Coord coord { get; set; }
public string country { get; set; }
}
public class RootObject
{
public string cod { get; set; }
public double message { get; set; }
public int cnt { get; set; }
public List<List> list { get; set; }
public City city { get; set; }
}
}
The problem is that your method is not static, so you need to create an instance of the Forecast class to access it. You can read more on this in this SO question and also here.
The quick solution also would be to make your Forecast class static (as long as you don't want to have multiple different instances of it):
static class Forecast
{
public static async void GetWeather()
{
var uri = new Uri("MY API URI HERE");
using (HttpClient client = new HttpClient())
{
using (HttpResponseMessage response = await client.GetAsync(uri))
{
using (IHttpContent content = response.Content)
{
var json = await content.ReadAsStringAsync();
var result = JsonConvert.DeserializeObject<RootObject>(json);
Debug.WriteLine("In async method");
}
}
}
}
}
But now we come upon a bigger problem. Your method is async and is async void. This is something you should do only when absolutely necessary as async void methods are so-called fire-and-forget. They start, but when they reach the first true asynchronous call, they will execute on their own and if something bad happens inside the method (like an exception) you will never know about it until the symptoms start appearing elsewhere in a hard-to-debug way. Also you never know when the result is actually ready for you to use.
The best solution is then Task return type. This presents a promise that the result will be available when the method execution is finished.
static class Forecast
{
public static RootObject Result {get; private set;}
public static async Task GetWeatherAsync()
{
var uri = new Uri("MY API URI HERE");
using (HttpClient client = new HttpClient())
{
using (HttpResponseMessage response = await client.GetAsync(uri))
{
using (IHttpContent content = response.Content)
{
var json = await content.ReadAsStringAsync();
Result = JsonConvert.DeserializeObject<RootObject>(json);
Debug.WriteLine("In async method");
}
}
}
}
}
You can see the method is no longer void but it still does not return the RootObject directly (as you requested, otherwise you could use Task<RootObject> to return it). I also added a Result property so that the result is accessible when the execution is finished. Because the class is static, the property is accessible from anywhere after the GetWeatherAsync method call finished.
Now how can you use this? Instead of the constructor you can call the method in OnNavigatedTo handler:
public override async void OnNavigatedTo(NavigationEventArgs e)
{
base.OnNavigatedTo( e );
try
{
await Forecast.GetWeatherAsync();
//after await finishes, Result is ready
//do something with Forecast.Result
}
catch
{
//handle any exceptions
}
}
You may notice that I violated the rule that async methods should not be void. However, in this case, we are dealing with event handler which has a fixed notation so you have no other choice. However, I have added a try-catch block so that we can handle any exceptions if they happen.
I recommend reading more on async-await in documentation as it will help you understand the concept much better. I also suggest you to check out more detailed info on instance vs. static to better understand the distinction and when to use each of them.
I am trying to set a class for a token using DeserializeObject from the json object i get back from my api. However when i run the below code it sets all the values to null or 0, not the result i am getting from the api.
cs code
var resultString = await result.Content.ReadAsStringAsync();
var post = JsonConvert.DeserializeObject<Token>(resultString);
class
public class Token : ContentPage
{
public int StaffID { get; set; }
public string TokenApi { get; set; }
public string StaffForename { get; set; }
public string StaffSurname { get; set; }
public string StaffEmail { get; set; }
public int PrimaryStaffRoleID { get; set; }
}
JSON response
"{\"code\":201,\"status\":\"Success\",\"message\":\"Object found\",\"data\":{\"StaffID\":14,\"StaffSurname\":\"Test\",\"StaffForename\":\"Test\",\"StaffEmail\":\"test#test.com\",\"PrimaryStaffRoleID\":5,\"TokenApi\":\"testToken\"}}"
Firstly the data which you are trying to map is inside another property in your json called Data and secondly your json does not have a property with name Token
The problem actually is you are not using the correct type that reflects your json, means you don't have correct c# type which would get mapped to json, you can generate correct types using json2charp.com , the correct classes for it are :
public class Data
{
public int StaffID { get; set; }
public string StaffSurname { get; set; }
public string StaffForename { get; set; }
public string StaffEmail { get; set; }
public int PrimaryStaffRoleID { get; set; }
public string TokenApi { get; set; }
}
public class RootObject
{
public int code { get; set; }
public string status { get; set; }
public string message { get; set; }
public Data data { get; set; }
}
Now deserializing using RootObject as type parameter would work perfectly fine like:
var resultString = await result.Content.ReadAsStringAsync();
var post = JsonConvert.DeserializeObject<RootObject>(resultString);
A more good option is to use QuickType.IO which would even generate code for you in c# or any other language that they are supporting.
If you analyze the JSON that you posted, the object that you're trying to Deserialize is inside the "data" property of your json.
I suggest you creating a class to represent the JsonResponse with a Data property. This will be your Token
You are retrieved a string that match this object
public string code {get;set;}
public string Success {get;set;} ...
And Token is matching data in json, so
var post = JsonConvert.DeserializeObject<Token>(resultString.data);
would be better.
I have a web api that returns a complex object that looks like this:
public class CanDeleteRumsaAttributeResponse
{
public CanDeleteRumsaAttributeResponse()
{
}
public CanDeleteRumsaAttributeResponse(int attributeId)
{
RumsaAttributeId = attributeId;
}
public int RumsaAttributeId { get; set; }
public bool AttributeFound { get; set; }
public List<RumsaRoom> AffectedRumsaRooms { get; set; } = new List<RumsaRoom>();
public List<RumsaAttribute> AffectedLinkedRumsaAttributes { get; set; } = new List<RumsaAttribute>();
[JsonIgnore]
public bool CanDelete
{
get
{
return AffectedRumsaRooms.Count == 0&&AttributeFound&&AffectedLinkedRumsaAttributes.Count==0;
}
}
}
When I debug it I can see that the controller return that object and that the list AffectedLinkedRumsaAttributes has several objects in the list
When the client receives the list all but the first object are null.
I've tried returning the object as Ok(CanDeleteRumsaAttributeResponse) and I've tried serializing it like this:
RoomAttributesUtils utils = new RoomAttributesUtils(db);
string json = JsonConvert.SerializeObject(utils.GetCanDeleteColor(id));
var response = this.Request.CreateResponse(HttpStatusCode.OK);
response.Content = new StringContent(json, Encoding.UTF8, "application/json");
return response;
In the second case I can search the json string and find the missing data.
So its being serialized in the second case.
I've checked fiddler to see what is being sent and I can see that something is not right in the json-data.
The missing objects gets values like $ref: "4" and so on, but nothing else.
Here is the json-string I'm afraid I dont know how to format it properly for Stackoverflow, but I think that the information is there as well, but when I look at it using a viewer, its not and it sure doesnt deserialize to the correct objects.
The other list in the object can have any number of objects and they all return fine. Also, other endpoints are returning lists of the same type perfectly fine.
The three objects have unique values on the Code property and they are V30, V31 and V12 (if you want to identify them in the json string).
Any ideas?
Here is the json string
{"RumsaAttributeId":4797,"AttributeFound":true,"AffectedRumsaRooms":[{"$id":"1","RoomName":"STÄD","RoomNumber":"U12102-1150","Building":"U1","PartOfBuilding":"21","Plan":"02","Number":"1150","RoomDescriptions":[],"IsDeleted":false,"PMs":[],"IDNR":"175D_40","Exclude":false,"Department":"VN40 Lokalvård","Comments":"","Area":"23.19","HygeneClass":null,"CeilingHeight":"","UniqueRoomId":"d00e5325-7918-4d01-b273-813a770b46ca-010591d3","SolviegHasOpenedThis":true,"LastSynchedFromRevit":"1900-01-01T00:00:00","LastUpdatedFromRevit":"1900-01-01T00:00:00","Id":25772}],"AffectedLinkedRumsaAttributes":[{"$id":"2","AMACode":"KBC.3211","Malning":"56-03510","AvaliableColors":[{"$id":"3","AvaliableMaterials":[{"$ref":"2"},{"$id":"4","AMACode":"MBE.221","Malning":"-","AvaliableColors":[{"$ref":"3"}],"RoomDescriptions":[],"Code":"V30","ShortDescription":"Kakel, vattenavvisande beklädnad","LongDescription":"-","Comment":"-","PartOfRoom":null,"PartOfRoomId":960,"Id":1438},{"$id":"5","AMACode":"MBE.222","Malning":"-","AvaliableColors":[{"$ref":"3"}],"RoomDescriptions":[],"Code":"V31","ShortDescription":"Kakel, vattentät beklädnad","LongDescription":"-","Comment":"-","PartOfRoom":null,"PartOfRoomId":960,"Id":1439}],"RoomDescriptions":[],"Code":"V31_01","ShortDescription":"Kakel, vattentät beklädnad","LongDescription":"Marazzi SistemC Arch ME83, kulör Bianco(vit)200x200x5 mm. Fog Mapei Ultracolor Plus kulör 111 Silver Grey","Comment":"På 1 fondvägg","PartOfRoom":null,"PartOfRoomId":960,"Id":4797}],"RoomDescriptions":[],"Code":"V12","ShortDescription":"Gipsskivor, hygienklass 2","LongDescription":"Hög standard, hygienklass 2\n","Comment":"-","PartOfRoom":null,"PartOfRoomId":960,"Id":1425},{"$ref":"4"},{"$ref":"5"}]}
I had a similar situation in which I found that due to circular references, the serialization was not completed.
public class Blog
{
public int BlogId { get; set; }
public string Url { get; set; }
public List<Post> Posts { get; set; }
}
public class Post
{
public int PostId { get; set; }
public string Title { get; set; }
public string Content { get; set; }
public int BlogForeignKey { get; set; }
[ForeignKey("BlogForeignKey")]
public Blog Blog {get;set;}
}
I just deleted the child to parent relationship and included the foreingkey anotation to the entity set.
public class Blog
{
public int BlogId { get; set; }
public string Url { get; set; }
[ForeignKey("BlogForeignKey")]
public List<Post> Posts { get; set; }
}
public class Post
{
public int PostId { get; set; }
public string Title { get; set; }
public string Content { get; set; }
public int BlogForeignKey { get; set; }
}
Also consider LoopReferenceHandling
I am setting a class in C# to hold a response that I will be receiving from a web service call. I'm using RestSharp to handle the calling / parsing of the JSON data.
The web service documentation describes the response as:
OUTPUT: JSON object similar to example below.
{
"response":"[success] or [failed]",
"messages":"Process succeeded.",
"logonkey":"[logon key]",
"tokenkey":"[security token]",
"reccount":"1",
"filelist":
{
"fileid":"12345",
"status":"N",
"filename":"data.tar",
"fulfilled":"2012-06-15"
}
}
My question is how can I define the filelist array element in my class?
I was thinking something like this:
public class Files
{
public string Response { get; set; }
public string Messages { get; set; }
public string LogonKey { get; set; }
public string TokenKey { get; set; }
public int RecordCount { get; set; }
public List<FileList>
}
public class FileList
{
public string FileID { get; set; }
public string Status { get; set; }
public string Filename { get; set; }
public DateTime Fulfilled { get; set; }
}
However, I'm having a problem with the "public List" statement.
Any suggestions on the best way to handle this scenario would be appreciated.
Also you forgot to give it a name, for example try this
public List<FileList> MyFavouriteList {get;set;}.
A proprety is declared like this "access modifier", "Type", "identifier(or name)", "getter and setter".
The filelist in JSON sample doesn't look like list of objects. Instead it is a single object.
You could try,
public class Files
{
public string Response { get; set; }
public string Messages { get; set; }
public string LogonKey { get; set; }
public string TokenKey { get; set; }
public int RecordCount { get; set; }
public FileList File {get; set; }
}
If you are sure the filelist in JSON is really list of object, you could try,
public List<FileList> Files = new List<FileList>();