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JavaScriptSerializer with custom Type

Asked 2009-06-22T13:03:51.277
10

I have a function with a List return type. I'm using this in a JSON-enabled WebService like:

  [WebMethod(EnableSession = true)]
    [ScriptMethod(ResponseFormat = ResponseFormat.Json)]
    public List<Product> GetProducts(string dummy)  /* without a parameter, it will not go through */
    {
        return new x.GetProducts();
    }

this returns:

{"d":[{"__type":"Product","Id":"2316","Name":"Big Something ","Price":"3000","Quantity":"5"}]}

I need to use this code in a simple aspx file too, so I created a JavaScriptSerializer:

        JavaScriptSerializer js = new JavaScriptSerializer();
        StringBuilder sb = new StringBuilder();

        List<Product> products = base.GetProducts();
        js.RegisterConverters(new JavaScriptConverter[] { new ProductConverter() });
        js.Serialize(products, sb);

        string _jsonShopbasket = sb.ToString();

but it returns without a type:

[{"Id":"2316","Name":"Big One ","Price":"3000","Quantity":"5"}]

Does anyone have any clue how to get the second Serialization work like the first?

Thanks!

asp.net javascriptserializer
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2 Answers

16

When you create the JavaScriptSerializer, pass it an instance of SimpleTypeResolver.

new JavaScriptSerializer(new SimpleTypeResolver())

No need to create your own JavaScriptConverter.

answered 2009-08-14T14:27:25.857
3

Ok, I have the solution, I've manually added the __type to the collection in the JavaScriptConverter class.

    public class ProductConverter : JavaScriptConverter
{        public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer)
    {
        Product p = obj as Product;
        if (p == null)
        {
            throw new InvalidOperationException("object must be of the Product type");
        }

        IDictionary<string, object> json = new Dictionary<string, object>();
        json.Add("__type", "Product");
        json.Add("Id", p.Id);
        json.Add("Name", p.Name);
        json.Add("Price", p.Price);

        return json;
    }
}

Is there any "offical" way to do this?:)

answered 2009-06-22T13:25:40.703

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