How to deserialize several nested Json arrays (more than 2) using DataContractJsonSerializer (Windows Phone 7)

Question

I need to deserialize the next Json string that has several nested Json arrays:

{"d1":[["11791452",[["980",""]]],["11791453",[["1060",""],["1140",""],["1220",""],["1300",""]]],["11791454",[["1070",""]]]]}

I try to do it in several steps, so far I'm able to deserialize three levels of nested arrays. As follow:

{"aOaOa":[[["1060",""],["1140",""],["1220",""],["1300",""]]]}

public class ThreeSimpleNestedArrays
{
    public List<List<string[]>> aOaOa;  //array of arrays of arrays

    public ThreeSimpleNestedArrays()
    {
        aOaOa = new List<List<string[]>>();
    }
}

But the problem arise when I add the extra string in the array structure:

{"TEST": [["11791453",[["1060",""],["1140",""],["1220",""],["1300",""]]],["123456",[["0","1"],["2","3"]]]]}

public class ComplexNestedArray
{
    public List<Dictionary<string,List<string[]> >> TEST;

    public ComplexNestedArray()
    {
        TEST = new List<Dictionary<string, List<string[]>>>();
    }
}

I'm getting the next error message: "Unable to cast object of type 'System.String' to type 'System.Collections.Generic.Dictionary`2[System.String,System.Object]'."

What am I missing?

Can anybody suggest a way to deserialize an object like this nested within Json arrays using DataContractJsonSerializer?

The code I use to deserialize is the next:

//Works
 DataContractJsonSerializer dcJsonSer = new DataContractJsonSerializer(typeof(ThreeSimpleNestedArrays));
        ThreeSimpleNestedArrays root = (ThreeSimpleNestedArrays)dcJsonSer.ReadObject(str);
//Don't work
        DataContractJsonSerializer dcJsonSer = new DataContractJsonSerializer(typeof(ComplexNestedArray));
        ComplexNestedArray root = (ComplexNestedArray)dcJsonSer.ReadObject(str);

Btw, I'm able to deserilize the object when it is serilized as a Json Object as follow:

 {"TEST": [{"s": "11791453","aOa": [["1060",""],["1140",""],["1220",""],["1300",""]]},{"s": "123456","aOa":[["0","1"],["2","3"]]}]}

using a class with two members (a string "s" and a List of string[] "aOa"), but without the names, when the object is serialized as an array, I'm unable to do it.

Any suggestion?

I think there is no simple way to achive that. The problem with your structure is that you have at the second level a struncture like this: string, string[]. So you have there mixed data types in a single array. — rekire
– rekire, Commented May 5, 2013 at 9:07
@rekire, yes, that would be my second task, but first I would like to understand if it is possible to read 3 nested arrays and/or what am I doing wrong, =/ — Alx
– Alx, Commented May 5, 2013 at 16:31

Alx · Accepted Answer · 2013-05-12 00:23:32Z

3

Ok, it looks like the DataContractJsonSerializer is smarter than I though .

It turns out that the way to deserialize that kid of nested objects array is with a class like this:

public class ComplexNestedArray
{
    //{"TEST": [["11791453",[["1060",""],["1140",""],["1220",""],["1300",""]]],["123456",[["0","1"],["2","3"]]]]}

    public List<List<object>> TEST { get; set; }
}

After that, it is only a mater to do a couple of for cycles and casts to the appropriate class structure.

Btw, This is a MUST in your toolbox in case you have to deal with Json:

json2csharp

answered May 12, 2013 at 0:23

Alx

291 silver badge8 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

rekire · Accepted Answer · 2013-05-05 19:21:17Z

0

Here is my solution. However I'll try to add later a way for your full json:

class Program {
    static void Main(string[] args) {
        new Program();
    }

    public Program() {
        string full = "{\"d1\":[[\"11791452\",[[\"980\",\"\"]]],[\"11791453\",[[\"1060\",\"\"],[\"1140\",\"\"],[\"1220\",\"\"],[\"1300\",\"\"]]],[\"11791454\",[[\"1070\",\"\"]]]]}";
        string simple1 = "{\"aOa\":[[\"1060\",\"\"],[\"1140\",\"\"],[\"1220\",\"\"],[\"1300\",\"\"]]}";
        string simple2 = "{\"aOaOa\":[[[\"1060\",\"\"],[\"1140\",\"\"],[\"1220\",\"\"],[\"1300\",\"\"]]]}";

        DataContractJsonSerializer d1 = new DataContractJsonSerializer(typeof(S1));
        S1 r1 = (S1)d1.ReadObject(new MemoryStream(Encoding.Default.GetBytes(simple1)));
        DataContractJsonSerializer d2 = new DataContractJsonSerializer(typeof(S2));
        S2 r2 = (S2)d2.ReadObject(new MemoryStream(Encoding.Default.GetBytes(simple2)));
        Console.WriteLine("done");
        Console.ReadKey();
    }

    [DataContract]
    class S1 {
        [DataMember]
        List<List<String>> aOa;
    }

    [DataContract]
    class S2 {
        [DataMember]
        List<List<List<string>>> aOaOa;
    }
}

edited May 5, 2013 at 19:21

answered May 5, 2013 at 18:58

rekire

48.1k34 gold badges184 silver badges279 bronze badges

4 Comments

Alx Over a year ago

Thanks!, I found a similar answer, but using a list of a string array List<List<string[]>> for the third nested array, though I'm still dealing when I add the string. I update my question, btw.

Alx Over a year ago

I try to use a member public List<List<Dictionary<string, List<string[]>>>> TEST; but this gives me the next error: "Unable to cast object of type 'System.String' to type 'System.Collections.ICollection'."

rekire Over a year ago

@Alx I tried some hours to get this running. IMHO it is impossible with normal deserialisation maybe it is possible with the interface IDataContractSurrogate, but I don't have the time to implement that.

Alx Over a year ago

I'll look at the hint, thanks for your support, I let you know if I found a way. =)

Collectives™ on Stack Overflow

How to deserialize several nested Json arrays (more than 2) using DataContractJsonSerializer (Windows Phone 7)

2 Answers 2

Comments

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related