如何在WebService中返回通用字典

using System.Collections.Generic;
using System.Web.Services;

[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
public class MyWebService : System.Web.Services.WebService
{
    [WebMethod]
    public Dictionary<string, object> GetData()
    {
        Dictionary<string, object> result = new Dictionary<string, object>();
        result.Add("key1", "value1");
        result.Add("key2", 2);
        result.Add("key3", true);
        return result;
    }
}