I am using the code below for populating a list
public class Group : List<Body>
{
public string Title { get; set; }
public Group(string title)
{
Title = title;
}
}
public class Body
{
public string Name { get; set; }
}
private void Button_Clicked(object sender, EventArgs e)
{
var items = new List<Group> {
new Group("Title")
{
new Body { Name = "Dimitris" } }
};
var jsonstring = JsonConvert.SerializeObject(items);
}
My result is
[[{"Name":"Dimitris"}]]
It doesnt get the title property. Is there any way which i can fix this?
Sadly not every object can be serialized into valid json. And as I said in the comments what you want (something that has both a title property but is also a list) cannot be presented in valid json (in json something can have properties {} or something can be a list [] but not both), there are more structures that cannot be represented in valid json (circular dependencies for example) but sadly this is one of them.
Now I understand the need to inherit List<Group> for the ListView so this poses a problem. However this is not a problem that can't be worked around.
You need to separate the json from the models you bind to your views (this is in general a good practice imo). So you create an object that carries the data and can be serialized into valid json:
public class BodyGroupDto
{
public string Title;
public List<Body> Items;
}
This can now be represented by the following json:
[{
"Title": "SomeTitle",
"Items": [{
"Name": "Dimitris"
}]
}]
Now that we have the ability to send the data with json we still need to be able to convert our data object to the actual Group object we want to use in the view.
One way to do this is to add another constructor to the Group class so we can pass it both a title and items:
public class Group : List<Body>
{
public string Title { get; set; }
public Group(string title)
{
Title = title;
}
public Group(string title, IEnumerable<Body> items) : base(items)
{
Title = title;
}
}
And now we can convert this inside the Xamarin Forms application, for example that could look like this:
public List<Group> GetGroups(string json)
{
var bodyGroupList = JsonConvert.DeserializeObject<List<BodyGroupDto>>(json);
return bodyGroupList.Select(bodyGroup => new Group(bodyGroup.Title, bodyGroup.Items)).ToList();
}
And if you ever need to convert the other way around you could do something like this:
public string GetBodyGroupDtoListJson(List<Group> groups)
{
var bodyGroupList = groups.Select(group => new BodyGroupDto
{
Title = group.Title,
Items = group.ToList()
}).ToList();
return JsonConvert.SerializeObject(bodyGroupList);
}
Hope this helps and good luck with your project
Related
So I've looked around for tutorials on this and all the tutorials I've found doesn't have JSON that looks like the one I'm trying to parse.
I'm trying to parse JSON from this website https://www.steamcardexchange.net/api/request.php?GetBadgePrices_Guest
Since it doesn't have any identifiers for each thing like name, id etc I'm not sure how I will go about extracting data from it.
My only interest is really getting the first number of each item
[["449940","! That Bastard Is Trying To Steal Our Gold !"],5,"$0.64","1519294200"]
so what I want to extract from this item would be "449940".
This is what I've got so far
using (var client = new WebClient())
{
client.DownloadFile("https://www.steamcardexchange.net/api/request.php?GetBadgePrices_Guest", "data.json");
}
using (StreamReader r = new StreamReader("data.json"))
{
string json = r.ReadToEnd();
//Parse somehow
}
Any tips?
I took this up out of sheer curiosity because I had no idea how to parse this either. Perhaps there's a much better way.
I started by pasting a fragment of this into json2csharp.com.
The class it generates is
public class RootObject
{
public List<List<object>> data { get; set; }
}
From there I wrote some classes that correspond to what I think the data is supposed to look like. The names of the classes and properties are meaningless, so change them to whatever these actually represent.
public class OutputItem
{
public Message Message { get; set; }
public long Int64Value { get; set; } // 5
public string StringThatLooksLikeCurrency { get; set; } // "$0.64"
public string StringThatLooksNumeric { get; set; } // "1519294200"
}
public class Message
{
public string MessageId { get; set; } // "449940"
public string MessageText { get; set; } // "! That Dude..."
}
And finally, some sample code that takes a fragment of that JSON and converts it to a list of OutputItem. In order to figure this out I first deserialized the JSON to RootObject, then I inspected the deserialized object in the debugger to make sense of what it looked like.
var json = #"{ ""data"": [[[ ""449940"", ""! That Dude Is Trying To Steal Our Gold !"" ], 5, ""$0.64"", ""1519294200"" ], [[ ""303720"", ""#killallzombies"" ], 5, ""$0.56"", ""1519322799"" ]]}";
var parsed = JsonConvert.DeserializeObject<RootObject>(json);
var outputItems = new List<OutputItem>();
foreach (var listOfObject in parsed.data)
{
var outputItem = new OutputItem();
var message = (JArray) listOfObject[0];
outputItem.Message = new Message {MessageId = (string) message[0],
MessageText = (string) message[1]};
outputItem.Int64Value = (long) listOfObject[1];
outputItem.StringThatLooksLikeCurrency = (string) listOfObject[2];
outputItem.StringThatLooksNumeric = (string) listOfObject[3];
outputItems.Add(outputItem);
}
First, this has been asked a number of times but having read all the posts I found none provided an answer that fixed my particular scenario.
Also, please forgive any incorrect terminology as I may be misusing terms...
I am trying to take the JSON from this query and simply output to a textblock:
http://www.imdb.com/xml/find?json=1&nr=1&nm=on&q=jeniffer+garner
Which produces this:
{
"name_approx":[
{
"id":"nm0004950",
"title":"",
"name":"Jennifer Garner",
"description":"Actress, Dallas Buyers Club"
},
//more code
{
"id":"nm3144518",
"title":"",
"name":"Jennifer Varner",
"description":"Self, THS Investigates: Hot for Student"
}]}
The code I'm trying to use for this as follows.
Classes:
public class Movie
{
public List<Stream> name_approx { get; set; }
public Movie ()
{}
}
public class Stream
{
public string id { get; set; }
public string title { get; set; }
public string name { get; set; }
public string description { get; set; }
public Stream ()
{}
}
and...
searchOutput.Text = "";
searchStatusOutput.Text = "Awaiting Response...";
string userURI = inputAddress.Text;
var response = await httpClient.GetAsync(userURI);
response.EnsureSuccessStatusCode();
var content = await response.Content.ReadAsStringAsync();
Movie output = JsonConvert.DeserializeObject<Movie>(content);
//searchOutput.Text = ??????
When I run this I can see that Movie Output correctly contains one 'name_approx' object and nested within it 20 'Streams' as I expect.
I cannot however figure out how to output this to my text block. I've tried numerous approaches and think I need to use some form of foreach however I'm stuck and cannot work it out.
Now that you have it as a Json object, you could serialize the parent object back to a formatted Json string and display it in <pre> tags to keep the formatting.
Json.Net has a method for this:
string json = JsonConvert.SerializeObject(movieObject, Formatting.Indented);
I have the following issue with this json :
{
"EVTS": {
"EVT": [
{ "ID": "123456",
"KEY1" : "somekey",
"CATEG": [
"cat1",
"cat2",
"cat3"
]
}
]}
}
and this c# class:
public class myClass{
public string ID { get; set; }
public string KEY1 { get; set; }
public list<string> CATEG { get; set; }
}
public class ESObject1
{
[JsonProperty("EVT")]
public List<myClass> EVT { get; set; }
}
public class ESObject0
{
[JsonProperty("EVTS")]
public ESObject1 EVTS { get; set; }
}
}
here i call the deserializer :
ESObject0 globalobject = JsonConvert.DeserializeObject<ESObject0>(json);
But this last code doesnt work, i throws this exception : System.ArgumentException: Could not cast or convert from System.String to System.Collections.Generic.List1[System.String].`
Instead of list<string> i used string [] and only string nothing seems to work.
how can i deserialize this object correctly please.
Thank you.
There doesn't seem to be any apparent problem wit hyour code as this working example illustrates:
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
public class myClass
{
public string ID { get; set; }
public string KEY1 { get; set; }
public List<string> CATEG { get; set; }
}
public class ESObject1
{
[JsonProperty("EVT")]
public List<myClass> EVT { get; set; }
}
public class ESObject0
{
[JsonProperty("EVTS")]
public ESObject1 EVTS { get; set; }
}
class Program
{
static void Main()
{
string json =
#"{
""EVTS"": {
""EVT"": [
{
""ID"": ""123456"",
""KEY1"": ""somekey"",
""CATEG"": [
""cat1"",
""cat2"",
""cat3""
]
}
]
}
}";
ESObject0 globalobject = JsonConvert.DeserializeObject<ESObject0>(json);
foreach (string item in globalobject.EVTS.EVT[0].CATEG)
{
Console.WriteLine(item);
}
}
}
Maybe you just fed a wrong json value to the deserializer which doesn't look like as the one shown in your question. By the way, the one shown i nyour question is invalid JSON as you are missing a , after KEY1 property declaration.
UPDATE:
Now that you have shown your real JSON (coming from http://donnees.ville.quebec.qc.ca/Handler.ashx?id=69&f=JSON) it appears that there's a row where CATEG is not an array of strings but a simple string:
""CATEG"": ""Conférence""
Now that's a pretty bad design because they are mixing arrays and simple properties. I am afraid that in order to deal with this situation you will need to use JObjects and extract the information you need by testing the actual underlying type.
For example:
var obj = JObject.Parse(json);
var events = (JArray)obj["EVTS"]["EVT"];
foreach (JObject evt in events)
{
var categories = evt["CATEG"];
if (categories is JArray)
{
// you've got a list of strings so you can loop through them
string[] cats = ((JArray)categories)
.Select(x => x.Value<string>())
.ToArray();
}
else
{
// you've got a simple string
string cat = categories.Value<string>();
}
}
I have done this many times with many many headaches. My advice is take the json output and use a tool similar to this to write your class for you (http://json2csharp.com/).
Then go over any nullable variables and add nullable type (ex. using int? for int) where needed.
I have a JSON data as follows
{"id": "367501354973","from": {
"name": "Bret Taylor",
"id": "220439" }
which is returned by an object(result) of IDictionary[String, Object]
In my C# code:
I have made a class for storing the JSON value which is as follows
public class SContent
{
public string id { get; set; }
public string from_name { get; set; }
public string from_id { get; set; }
}
My main C# function which stores the parses the JSON data and stores the value inside the class properties is as follows:
List<object> data = (List<object>)result["data"];
foreach (IDictionary<string, object> content in data)
{
SContent s = new SContent();
s.id = (string)content["id"];
s.from_name = (string)content["from.name"];
s.from_id = (string)content["from.id"];
}
When i execute this code, i get an exception saying System cannot find the Key "from.name" and "from.id"
When i comment the two lines (s.from_name = (string)content["from.name"];s.from_id = (string)content["from.id"];) my code runs fine.
I think i am not able to refer the nested JSON data properly.
Can anyone just validate it and please tell me how to refer nested data in JSON in C#?
Thanks
I'm not sure how you are parsing the JSON string. Are you using a class in the Framework to do the deserialization?
You could use the JavaScriptSerializer Class defined in the System.Web.Script.Serialization Namespace (you may need to add a reference to System.Web.dll)
Using that class, you would write your code like this:
public class SContent
{
public string id { get; set; }
public SFrom from { get; set; }
}
public class SFrom
{
public string name { get; set; }
public string id { get; set; }
}
Then deserialization looks like this:
var json = new JavaScriptSerializer();
var result = json.Deserialize<SContent>(/*...json text or stream...*/);
See JavaScriptSerializer on MSDN. You might also want to check out this similar question.
I have the following Json string that I need to deserialize.
{"123456789":
{"short_description":"Delivered",
"detail_description":"Your item has been delivered"
}
}
The first field "123456789" is an id number, so basically this value can be different depending on the data being queried.
I'm using C# in visual studio. Obviously because the value of the first field can change I can't use a predefined class to deserialize the JSON into because this field will be used as the class name but the field value won't match the class name.
Is there a way to deserialize this into some sort of dynamic class but still access the fields as if it was a predefined class?
Alternatively is there a way to deserialize this into a predefined class even thought the class name doesn't match?
The service providing this data is a third party one so i don't have any control over it.
Here is one way which I use in production code. It might not be perfect, but it gets the job done.
using using System.Web.Script.Serialization;
// .....
public object GetJson(string url)
{
var json = Get(url); // I have code that makes this work, it gets a JSON string
try
{
var deserializer = new JavaScriptSerializer();
var result = deserializer.DeserializeObject(json);
return result;
}
catch (ArgumentException e)
{
// Error handling....
}
}
The object you receive back will be a generic Map, List, or whatever depending on the structure of the JSON. If you know what structure to expect, this is very useful without writing a customized parser or target object type.
You could then enumerate the keys of the Map, for example, to find your key that varies. A wrapper or conversion would then provide a consistent API to the rest of your application layer. Something like:
public class Order {
public string OrderNum { private set; get; }
public string ShortDesc { private set; get; }
public string Desc { private set; get; }
public static Order FromJson(object jsonResult)
{
var m = jsonResult as Map<string, object>;
// Handle errors, but I am not
var firstPair = m.First();
var detail = firstPair.Value as Map<string, object>;
var dummy = new Order()
{
OrderNum = firstPair.Key,
ShortDesc = detail["short_description"].ToString();
Desc = detail["detail_description"].ToString();
}
return dummy;
}
}
I liked answer above so I refactored it a bit. You'll need references to System.Web.Extensions.dll and System.Web.Script.Serialization.
Here's the class:
public class Order
{
public string OrderNum { private set; get; }
public string ShortDesc { private set; get; }
public string Desc { private set; get; }
public static Order FromJson(string jsonResult)
{
JavaScriptSerializer js = new JavaScriptSerializer();
// Should deserialize right to Dictionary<string, object>
// var result = ((Dictionary<string, object>)js.Deserialize<dynamic>(jsonResult)).First();
var result = js.Deserialize<Dictionary<string, object>>(jsonResult).First();
var detail = (Dictionary<string, object>)result.Value;
return new Order()
{
OrderNum = result.Key,
ShortDesc = detail["short_description"].ToString(),
Desc = detail["detail_description"].ToString()
};
}
}
And how to call it:
string json = "{\"123456789\": {\"short_description\":\"Delivered\", \"detail_description\":\"Your item has been delivered\" } }";
Order o = Order.FromJson(json);
You'll need to implement error handling on your own however.