I have flat C# class with lots of properties and I want to serialize an instance of that class into JSON using Json.NET. While serializing, I need to produce a JSON string that is nested. I know that I can create subclasses to achieve this but this is unnecessary overhead.
Let's assume I have this class:
public class MyClass{
[JsonProperty("subgroupa.myotherproperty")]
public int MyProperty {get;set;} = 5;
}
How can I get this JSON:
{
"subgroupa": {
"myotherproperty": 5
}
}
In the past, I was able to deserialize such a nested JSON string into a flat object. Therefore, I believe Json.NET can also do the opposite.
using System.Text.Json;
public class MyClass{
[JsonProperty("subgroupa.myotherproperty")]
public int MyProperty {get;set;} = 5;}
string subgroupa = JsonSerializer.Serialize(MyClass);
Related
I have some JSON:
{
"foo" : [
{ "bar" : "baz" },
{ "bar" : "qux" }
]
}
And I want to deserialize this into a collection. I have defined this class:
public class Foo
{
public string bar { get; set; }
}
However, the following code does not work:
JsonConvert.DeserializeObject<List<Foo>>(jsonString);
How can I deserialize my JSON?
That JSON is not a Foo JSON array. The code JsonConvert.DeserializeObject<T>(jsonString) will parse the JSON string from the root on up, and your type T must match that JSON structure exactly. The parser is not going to guess which JSON member is supposed to represent the List<Foo> you're looking for.
You need a root object, that represents the JSON from the root element.
You can easily let the classes to do that be generated from a sample JSON. To do this, copy your JSON and click Edit -> Paste Special -> Paste JSON As Classes in Visual Studio.
Alternatively, you could do the same on http://json2csharp.com, which generates more or less the same classes.
You'll see that the collection actually is one element deeper than expected:
public class Foo
{
public string bar { get; set; }
}
public class RootObject
{
public List<Foo> foo { get; set; }
}
Now you can deserialize the JSON from the root (and be sure to rename RootObject to something useful):
var rootObject = JsonConvert.DeserializeObject<RootObject>(jsonString);
And access the collection:
foreach (var foo in rootObject.foo)
{
// foo is a `Foo`
}
You can always rename properties to follow your casing convention and apply a JsonProperty attribute to them:
public class Foo
{
[JsonProperty("bar")]
public string Bar { get; set; }
}
Also make sure that the JSON contains enough sample data. The class parser will have to guess the appropriate C# type based on the contents found in the JSON.
I have a class Response with generic parameter:
public class Response<T> where T : class {
public bool Result;
public T Data;
}
Also, I have a class Instance with simple parameters
public sealed class Instance {
public long Rank { get; set; }
public int ID_Member { get; set; }
}
And then I have a class where I use last ones
public sealed class InstanceResponse : Response<IList<Instance>> { }
And I try to add a constructor to last class and don't understand how to do it
I've tried like there, but it's doesn't work, JsonString contains serialized class InstanceResponse
public sealed class InstanceResponse : Response<IList<Instance>> {
public InstanceResponse(string JsonString) {
this = JsonConvert.DeserializeObject<InstanceResponse>(JsonString);
}
}
I've got an error Cannot assign to 'this' because it is read-only
How it possible?
It's not possible to deserialize json to the object and assign it directly in ctor to the object itself using this keyword.
Provided that
Json contains serialized class InstanceResponse
You can do something like this:
public sealed class InstanceResponse : Response<IList<Instance>> {
public InstanceResponse(string JsonString) {
var response = JsonConvert.DeserializeObject<InstanceResponse>(JsonString);
this.Data = response.Data;
this.Result = response.Result;
}
}
Another possible solution is to deserialize json in a code that creates instance of InstanceResponse (call's ctor) somewhere.
Instead of:
var response = new InstanceResponse(json);
You could deserialize json right there:
var response = JsonConvert.DeserializeObject<InstanceResponse>(json);
P.S.
With that being said, an interesting point was raised by #Lasse Vågsæther Karlsen regarding the subject. It is actually possible to assign something to this however it is only working inside of a structs ctor and use cases for it are very limited...(thanks Lasse)
I have some JSON:
{
"foo" : [
{ "bar" : "baz" },
{ "bar" : "qux" }
]
}
And I want to deserialize this into a collection. I have defined this class:
public class Foo
{
public string bar { get; set; }
}
However, the following code does not work:
JsonConvert.DeserializeObject<List<Foo>>(jsonString);
How can I deserialize my JSON?
That JSON is not a Foo JSON array. The code JsonConvert.DeserializeObject<T>(jsonString) will parse the JSON string from the root on up, and your type T must match that JSON structure exactly. The parser is not going to guess which JSON member is supposed to represent the List<Foo> you're looking for.
You need a root object, that represents the JSON from the root element.
You can easily let the classes to do that be generated from a sample JSON. To do this, copy your JSON and click Edit -> Paste Special -> Paste JSON As Classes in Visual Studio.
Alternatively, you could do the same on http://json2csharp.com, which generates more or less the same classes.
You'll see that the collection actually is one element deeper than expected:
public class Foo
{
public string bar { get; set; }
}
public class RootObject
{
public List<Foo> foo { get; set; }
}
Now you can deserialize the JSON from the root (and be sure to rename RootObject to something useful):
var rootObject = JsonConvert.DeserializeObject<RootObject>(jsonString);
And access the collection:
foreach (var foo in rootObject.foo)
{
// foo is a `Foo`
}
You can always rename properties to follow your casing convention and apply a JsonProperty attribute to them:
public class Foo
{
[JsonProperty("bar")]
public string Bar { get; set; }
}
Also make sure that the JSON contains enough sample data. The class parser will have to guess the appropriate C# type based on the contents found in the JSON.
Currently, I have some JSON data that I am attempting to deserialize using the DataContractJsonSerializer class. However, one of the arrays in the data contains multiple types of objects. Is there a way to deserialize this data properly? I am aware that a very similar question exists, but I would prefer not to use Json.NET or any other third-party libraries.
EDIT: A small example:
In this instance, let's say the JSON is of form [{"foo":string},{"bar":string},{"foo":string},{"foo":string},...] where each element is either of form {"foo":string} or {"bar":string}. Then, the contracts could be set up as such:
[DataContract]
class Foo { [DataMember] public string foo; }
[DataContract]
class Bar { [DataMember] public string bar; }
In this context, my question is, how do I deserialize this array of Foos and Bars?
This does not sound right. There should not be two completely different types in a single array. Given the JSON provided I would try something like this....
[DataContract]
class SomeClass
{
[DataMember]
public string foo { get; set;}
[DataMember]
public string bar { get; set;}
}
Then check for IsNullOrWhiteSpace() on each property.
Updated with more code...
static void Main(string[] args)
{
SomeClass[] output;
var json = "[{\"foo\":\"value\"},{\"bar\":\"value\"},{\"foo\":\"value1\"},{\"foo\":\"value1\"}]";
using (var ms = new MemoryStream(Encoding.Unicode.GetBytes(json)))
{
var deserializer = new DataContractJsonSerializer(typeof(SomeClass[]));
output = (SomeClass[])deserializer.ReadObject(ms);
}
// do something with output
Console.WriteLine(output.Length);
}
Is it possible to deserialize a single object from multiple XML files? For example, if I have the following class:
[XmlInclude(typeof(SubClass))]
[XmlRoot]
public class BaseClass
{
[XmlElement]
public virtual int CommonSetting { get; set; }
}
[XmlRoot]
public class SubClass : BaseClass
{
[XmlElement]
public int OtherSetting { get; set; }
}
I want to deserialize an instance of 'SubClass' from XML, but I want to split the definition into two distinct files. For example:
BaseClass.xml
<BaseClass>
<CommonSetting>10</CommonSetting>
</BaseClass>
SubClass.xml
<SubClass>
<OtherSetting>5</OtherSetting>
</SubClass>
And secondly, is it then possible to override inherited 'common' settings by setting them inside the 'SubClass.xml' file. For example, if I defined 'SubClass.xml' as:
<SubClass>
<CommonSetting>5</CommonSetting>
<OtherSetting>5</OtherSetting>
</SubClass>
Then I would like to have an object 'Subclass' with a 'CommonSetting' of 5, rather than 10.
Is the above possible and if so, how can I go about it? Currently all I can achieve is to deserialise an instance of 'BaseClass' and 'SubClass' separately, and 'SubClass' has null/default values for settings derived from 'BaseClass'.