Trying to deserialize JSON using JSON.NET and DataContractJsonSerializer fails

问题

plz help, I'm stuck. I have a WCF service which returns something like this:

{
   "GetDataRESTResult":
     [
       {"Key1":100.0000,"Key2":1,"Key3":"Min"},
       {"Key1":100.0000,"Key2":2,"Key3":"Max"}
     ]
}

and I would like to deserialize it, but whatever I use (JSON.NET or DataContractJsonSerializer) I'm getting errors. When using DataContractJsonSerializer I'm using theis code:

byte[] data = Encoding.UTF8.GetBytes(e.Result);
MemoryStream memStream = new MemoryStream(data);
DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(List<DataDC>));
List<DataDC> pricinglist = (List<DataDC>)serializer.ReadObject(memStream);

where DataDC is the data contract which I've got from the service reference of the WCF REST service I'm getting the JSON data from, and the error I'm getting is InvalidCastException...

Trying to use JSON.NET I get another exception, but still nothing I can figure out, can anyone help please?

EDIT Here's a JSON.NET stacktrace:

Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1[MyApp.MyServiceReference.DataDC]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly. To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object. Path 'GetDataRESTResult', line 1, position 23.

回答1:

Below code works

string json = @" {""GetDataRESTResult"":[{""Key1"":100.0000,""Key2"":1,""Key3"":""Min""},{""Key1"":100.0000,""Key2"":2,""Key3"":""Max""}]}";

dynamic dynObj = JsonConvert.DeserializeObject(json);
foreach (var item in dynObj.GetDataRESTResult)
{
    Console.WriteLine("{0} {1} {2}", item.Key1, item.Key3, item.Key3);
}

You can also use Linq

var jObj = (JObject)JsonConvert.DeserializeObject(json);
var result = jObj["GetDataRESTResult"]
                .Select(item => new
                {
                    Key1 = (double)item["Key1"],
                    Key2 = (int)item["Key2"],
                    Key3 = (string)item["Key3"],
                })
                .ToList();

回答2:

{"GetDataRESTResult":[{"Key1":100.0000,"Key2":1,"Key3":"Min"},{"Key1":100.0000,"Key2":2,"Key3":"Max"}]}

You data is a JSON object (where it has one key 'GetDataRESTResult' with a JSON array as the value). Because of that, the type you should deserialize into should be an object, not a collection.

DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(DataDC));
DataDC pricinglist = (DataDC)serializer.ReadObject(memStream);

It will work if your type DataDC look something like this:

public class DataDC
{
    public List<Keys> GetDataRESTResult { get; set; }
}
public class Keys
{
    public double Key1 { get; set; }
    public int Key2 { get; set; }
    public string Key3 { get; set; }
}

来源：https://stackoverflow.com/questions/12699257/trying-to-deserialize-json-using-json-net-and-datacontractjsonserializer-fails

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datacontractserializer