使用 C# 使用 JSON 进行反序列化的问题

Question

I have looked over example after example after example and none of my attempts have worked.

I'm attempting to deserialize this JSON return:

{
  "status": "success",
  "data": {
    "result": "match",
    "id_user": 26564,
    "dob_match": null,
    "first_name_match": null,
    "last_name_match": null
  },
  "code": 200
}

Here is my JSON object class declaration:

[DataContract]
internal class DccCoachApi
{
    [DataMember]
    public string result { get; set; }
    public string id_user { get; set; }
    public string dob_match { get; set; }
    public string first_name_match { get; set; }
    public string last_name_match { get; set; }
}

In my stream method, my streamRead variable is filled with: {"status":"success","data":{"result":"match","id_user":26564,"dob_match":null,"first_name_match":null,"last_name_match":null},"code":200}

Method 1 does not populate coachId:

            using (var ms = new MemoryStream(Encoding.Unicode.GetBytes(streamRead)))
            {
                // Deserialization from JSON  
                var deserializer = new DataContractJsonSerializer(typeof(DccCoachApi));
                var dccObj = (DccCoachApi)deserializer.ReadObject(ms);
                coachId = dccObj.id_user;
            }

Nor does method 2:

            DccCoachApi coach = new JavaScriptSerializer().Deserialize<DccCoachApi>(streamRead);

            coachId = coach.id_user;

nor does method 3:

            JavaScriptSerializer js = new JavaScriptSerializer();
            DccCoachApi dccObj = js.Deserialize<DccCoachApi>(streamRead);
            coachId = dccObj.id_user;

nor does method 4:

            dynamic dccObject = js.Deserialize<dynamic>(streamRead);
            coachId = dccObject["id_user"];

The hard error that gets produced when i pull the value directly off method 4 is: System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary. at System.Collections.Generic.Dictionary`2.get_Item(TKey key)

Methods 1-3 do not hit a hard error, however they populate coachId with no data.

Can somebody please let me know what i'm doing wrong?

Answer 1

You can simply generate proper classes here: http://json2csharp.com/

This is how it should look like you don't need the DataMember Attributes, it might confuse the serializer to only de-serialize this single property:

public class Data
{
    public string result { get; set; }
    public int id_user { get; set; }
    public object dob_match { get; set; }
    public object first_name_match { get; set; }
    public object last_name_match { get; set; }
}

public class RootObject
{
    public string status { get; set; }
    public Data data { get; set; }
    public int code { get; set; }
}

Code:

var deserializer = DataContractJsonSerializer(typeof(RootObject));
var root = (RootObject)deserializer.ReadObject(ms);
var coachId = root.data.id_user;

Answer 2

I revised the code to look like this, and it is dumping my value perfectly. Thanks much to everyone who helped me reach the solution. Plutonix, thanks as well for the paste special 411. I had no idea that existed. VERY useful!

                using (var reader = new StreamReader(webResponse.GetResponseStream()))
            {
                var streamRead = reader.ReadToEnd();
                reader.Close();
                using (var ms = new MemoryStream(Encoding.Unicode.GetBytes(streamRead)))
                {
                    JavaScriptSerializer js = new JavaScriptSerializer();
                    DccCoachRootobject dccObj = js.Deserialize<DccCoachRootobject>(streamRead);
                    coachId = dccObj.data.id_user.ToString();
                }
            }