Parse JSON to a Dictionary<string, List<string>>

Question

I have a JSON node similar to the following.

"folders":[
    {"Videos":[1196717,2874999,898084]},
    {"Fun":[2443301,3671]},
    {"News":[62689,58867,11385]}
]

I want to deserialize it into a Dictionary<string, List<int>> or something similar. I currently have the member:

[DataMember(Name = "folders")]
public Dictionary<string, List<int>> Folders;

And I expect an output like:

Folders = new Dictionary<string, List<int>>() {
    {"Videos", new List<int>() { 1196717, 2874999, 898084 }},
    {"Fun",    new List<int>() { 2443301, 3671 }},
    {"News",   new List<int>() { 62689, 58867, 11385 }}
};

I've implemented the deserializer as:

var serializer = new DataContractJsonSerializer(
    typeof(T),
    new DataContractJsonSerializerSettings() {
        DateTimeFormat = new DateTimeFormat("yyyy-MM-ddTHH:mm:ss.fffffffZ"),
    }
);
T result = (T)serializer.ReadObject(response);

But the just produces the error:

The data contract type 'System.Runtime.Serialization.KeyValue`2[[System.String, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.Collections.Generic.List`1[[System.Int32, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]], mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]]' cannot be deserialized because the required data members 'Key, Value' were not found.

I understand this is because it is expecting something more like this, but the format is out of my control.

"folders":[
    {
        "key":"Videos",
        "value":[1196717,2874999,898084]
    },{
        "key":"Fun",
        "value":[2443301,3671]
    },{
        "key":"News",
        "value":[62689,58867,11385]
    }
]

What can I do to deserialize this?

Answer 1

Having: C#

public class wrap
{
    public List<Dictionary<string, List<string>>> folders { get; set; }
}

Json:

{"folders":[
    {"Videos":[1196717,2874999,898084]},
    {"Fun":[2443301,3671]},
    {"News":[62689,58867,11385]}
]
}

Using NewtonJson deserializer:

JsonDeserializer.Deserialize<wrap>(JsonInput)

I got successful object with List of 3 items of dictionaries.

Using DataContractJsonSerializer:

var serialzier = new DataContractJsonSerializer(typeof(wrap));
var stream = new MemoryStream(Encoding.UTF8.GetBytes(JsonInput));
Result = (wrap)serialzier.ReadObject(stream);

I got Unsuccessful object with List of 3 items of dictionaries, but they were empty. Maybe DataContractJsonSerializer needs some tweaking?

Hope it helps.

Answer 2

I used JavaScriptSerializer for this. Basically your json is actually a Dictionary<string, object> . I'm not sure why it would not let to do the casting to list, but any way, here are few simple lines which allows you to accomplish your task.

Note that i used this as jsonString (ie without the "video:" part)

[
    {"Videos":[1196717,2874999,898084]},
    {"Fun":[2443301,3671]},
    {"News":[62689,58867,11385]}
]

If you want it with the video, then it is one more level of dictionary, ie Dictionary<string, Dictionary<string, object>> but works in same manner

Code:

    Dictionary<string, List<int>> result = new Dictionary<string, List<int>>();
    object[] desirializedJsonObject =(object[])new JavaScriptSerializer().DeserializeObject(jsonString);
    foreach (var obj in desirializedJsonObject)
    {
        // Get the record
        var firstRecord   = ((Dictionary<string, object>)obj).First();

        // Creat list of values
        var listOfValues = ((object[])firstRecord.Value).Select(x => Convert.ToInt32(x)).ToList();

        result.Add(firstRecord.Key, listOfValues);
    }

Answer 3

使用KeyValuePair类代替字典，

List<KeyValuePair<string, List<string>>> uploadedfiles = JsonConvert.DeserializeObject<List<KeyValuePair<string, List<string>>>>(json)