Exception while Parsing JSON with DataContractJsonSerializer

Question

I don't know if this is me or the JSON that I am getting. Anyhow I was reading this other article which I thought was relevant but no idea what the guys was talking about when he figured out what he needed to to more json c# issues

here is a sample of the JSON I am getting now

{
    "totalResult": 2,
    "merchants": {
        "1718167": {
            "merchantRank": "29",
            "merchantName": "bob the builders factory",
            "merchantSlogan": "if he can't fix it we can",
            "merchantBdesc": "",
            "merchantLogo": "pic1.gif",
            "merchantLink": "http:\/\/www.randomlink.com\/",
            "merchantAddress": "place
street St
area
city
1111",
            "merchantLat": "-15.9935425",
            "merchantLng": "58.0836955",
            "merchantGeoLevel": "st",
            "merchantDistance": "0.00",
            "merchantCategories": "builder",
            "merchantEmail": "",
            "merchantUrl": "http:\/\/www.randomlink.com\/",
            "merchantPhone": "0123456789",
            "merchantMobile": "",
            "merchantSrc": "AJF"
        },
        "113711": {
            "merchantRank": "229",
            "merchantName": "A A A Builders",
            "merchantSlogan": "",
            "merchantBdesc": "",
            "merchantLogo": "pic26.gif",
            "merchantLink": "http:\/\/www.randomlink.com\/",
            "merchantAddress": "",
            "merchantLat": "",
            "merchantLng": "",
            "merchantGeoLevel": "",
            "merchantDistance": "0.00",
            "merchantCategories": "Builder",
            "merchantEmail": "here@randomlink.com",
            "merchantUrl": "http:\/\/randomlink.com",
            "merchantPhone": "0123456789",
            "merchantMobile": "",
            "merchantSrc": "GHF"
        }
    }
}

for the sake of sanity I have reduced the number of results, anyways, so I was attempting to build the data contracts for this and I came into an issue that I had previously, where some clever trickery got me the results that I need. However this time its different...

Using the [DataContract] I can get the totalResult, however, to get merchants I keep getting errors... and I believe that because the "113711", and the "113711" are dynamic this causes a problem to create a data model. So I thought that perhaps a dictionary would solve this problem. However whenever I try it I get errors!!

Here is what I tried to use:

[DataContract]
public class result
{
    [DataMember(Name = "totalResult")]
    public string totalResult { get; set; }
    [DataMember(Name = "merchants")]
    public Dictionary<string, metchant_info> merchants { get; set; }
}
[DataContract]
public class metchant_info
{
    [DataMember(Name = "merchantRank")]
    public string merchantRank;
    [DataMember(Name = "merchantName")]
    public string merchantName;
    [DataMember(Name = "merchantSlogan")]
    public string merchantSlogan;
    [DataMember(Name = "merchantBdesc")]
    public string merchantBdesc;
    [DataMember(Name = "merchantLogo")]
    public string merchantLogo;
    [DataMember(Name = "merchantLink")]
    public string merchantLink;
    [DataMember(Name = "merchantAddress")]
    public string merchantAddress;
    [DataMember(Name = "merchantLat")]
    public string merchantLat;
    [DataMember(Name = "merchantLng")]
    public string merchantLng;
    [DataMember(Name = "merchantGeoLevel")]
    public string merchantGeoLevel;
    [DataMember(Name = "merchantDistance")]
    public string merchantDistance;
    [DataMember(Name = "merchantCategories")]
    public string merchantCategories;
    [DataMember(Name = "merchantEmail")]
    public string merchantEmail;
    [DataMember(Name = "merchantUrl")]
    public string merchantUrl;
    [DataMember(Name = "merchantPhone")]
    public string merchantPhone;
    [DataMember(Name = "merchantMobile")]
    public string merchantMobile;
    [DataMember(Name = "merchantSrc")]
    public string merchantSrc;
}

and here is the code behind...

            try
            {
                Stream responseStream = e.Result;
                DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(result));
                result response = (result)ser.ReadObject(responseStream);
            }
            catch (Exception ex)
            {
                return;
            }

The error I am getting currently is :

"Could not evaluate expression"

if you want the stack trace I will post it, but its a rather large amount of useless information... Also if you change the datamember Merchants to a string you will see the following error:

"System.Collections.Generic.Dictionary`2[System.String,System.Object]"

So... any thoughts?

Regarding - "System.Collections.Generic.Dictionary`2[System.String,System.Object]" where is the rest of this error? — Stuart.Sklinar, May 02 '12 at 12:33
@Stuart.Sklinar that is what is returned in the string, there is no further information — Ghostfire, May 02 '12 at 13:06
@Ghostfire (RE: @Tarion) Something that related directly to THIS question, and not something that could be related to another question :) Oh and something descriptive about the question! — Stuart.Sklinar, May 02 '12 at 13:52

score 3 · Accepted Answer · answered May 02 '12 at 12:47

Using Json.Net, you can handle the case dynamically as below

var obj = (JObject)JsonConvert.DeserializeObject(json);

foreach (var item in obj["merchants"])
{
    Console.WriteLine(item.First()["merchantName"]);
}

or you can deserialize each merchant to your metchant_info object in a loop

foreach (var item in obj["merchants"])
{
    var m = JsonConvert.DeserializeObject<metchant_info>(item.First().ToString());
    Console.WriteLine(m.merchantName);
}

score 0 · Answer 2 · edited May 23 '17 at 10:32

I dont have a working solution but after a bit of research, I found the following information:

Looking at this Question: How would I read into a 'nested' Json file with 'DataContractJsonSerializer' in C# .NET (win7 phone)? the problem seems to be the

public Dictionary<string, metchant_info> merchants { get; set; }

There seems to be an issue with the way the Serializer handles Dictionaries: Deserialization problem with DataContractJsonSerializer

Any way to make DataContractJsonSerializer serialize Dictionaries properly?

Hope you can figure it out.

Exception while Parsing JSON with DataContractJsonSerializer

2 Answers2