Deserialize nested JSON into C# class

Question

I have a JSON class like this

{
    "Items": {
        "Item_1A": {
            "prop1": "string",
            "prop2": "string",
            "prop3": 1,
            "prop4": [{
                "prop_x": 100
            },
            {
                "prop_y": 200
            }]
        },
        "Item2B": {
            "prop1": "string",
            "prop2": "string",
            "prop3": 14,
            "prop4": [{
                "prop_z": 300
            }]
        }
    }
}

How could I make it into C# classes? Here is what I have so far:

public class Info
{
    public string prop1 {get;set;}
    public string prop2 {get;set;}
    public int prop3 {get;set;}
    public Dictionary<string, List<int>> prop4 {get;set;}
}
public class Response
{
    public Dictionary<string, List<Info>> Item {get;set;}
}

I tried to follow this link, but did not work Deserialize nested JSON into C# objects

Answer 1

Here's a tip to create proxy classes after a json:

First of all, to make sure it is a valid JSON, go to this website and run the validator: https://jsonlint.com/

If it is ok, there are some tools that convert json and xml to a c# proxy class directly like: http://json2csharp.com/ : https://xmltocsharp.azurewebsites.net/

Now there you go! just copy them to your Model and start using it.

Answer 2

Just some small changes to your model. Your prop4 is instead a List or Array.

public class Info
{
  public string prop1 {get;set;}
  public string prop2 {get;set;}
  public int prop3 {get;set;}
  public List<Dictionary<string, List<int>>> prop4 {get;set}
}
public class  Response
{
  public class Dictionary<string, Info> Items {get;set;} // Should be named Items
}

Answer 3

Your prop4 is a Dictionary<string, List<int>>, which when serialized looks something like this (I've omitted $type properties in the emitted JSON for brevity):

{
   "X": {
      "$values": [ 1, 2 ]
   },
   "Y": {
      "$values": [ 3, 4 ]
   }    
}

Your JSON, while well formed, is "shaped" wrong. It looks more like an array containing a dictionary of one item.

In the JSON above, X and Y are keys in the dictionary, which is a "regular object" modeled in JSON. The $values represents the list of integers for each key.

Answer 4

Your data model should be as follows:

public class Info
{
    public string prop1 {get;set;}
    public string prop2 {get;set;}
    public int prop3 {get;set;}
    // Modified from 
    //public Dictionary<string, List<int>> prop4 {get;set}
    public List<Dictionary<string, int>> prop4 {get;set;}
}

public class Response
{
    // Modified from 
    //public class Dictionary<string, List<Info>> Item {get;set;}
    public Dictionary<string, Info> Items {get;set;}
}

Notes:

• Response.Item should have been named Items.

• In your JSON, "Items" is an object with variably-named object-valued properties:

  {
      "Items": {
          "Item_1A": { },
          "Item2B": { }
      }
  }
  

  This should be modeled as a Dictionary<string, T> for an appropriate non-collection type T. Assuming you are using json.net see Serialization Guide: Dictionaries for details. If not, javascriptserializer behaves similarly.

  Your data model, public class Dictionary<string, List<Info>> Items, would have been appropriate for an object with variably-named array-valued properties:

  {
      "Items": {
          "Item_1A": [{ },{ }],
          "Item2B": [{ }]
      }
  }
  

  But this is not what you have.

• Meanwhile "prop4" is an array containing object with variably-named object-valued properties such as:

  "prop4": [ // Outer container is an array
    {        // Inner container is an object
      "prop_x": 100
    },
    {
      "prop_y": 200
    }
  ]
  

  Thus a collection such as List<T> should be used as the outer generic type:

  public List<Dictionary<string, int>> prop4 {get;set;}
  

  See Serialization Guide: IEnumerable, Lists, and Arrays.

• As you have noticed, code-generation tools such as those mentioned in How to auto-generate a C# class file from a JSON object string generally cannot recognize JSON objects with variable property names. In such a situation an auto-generated class may need to get manually replaced with an appropriate Dictionary<string, T> property in the containing type.

Sample working fiddle here.