I am converting an object to JSON using JavaScriptSerializer and I can see this JSON output in server code:
JavaScriptSerializer
[{\"UserId\":1,\"UserName\":\"Admin\"}]
If you are using the Razor view engine you need to use the Html.Raw method:
Html.Raw
Notice the usage of the Json.Encode method which is shorter and equivalent to new JavaScriptSerializer().Serialize().
Json.Encode
new JavaScriptSerializer().Serialize()