Create JSON object or string..? - asp.net

Question

Can we initialize JSON object with a string in C# ;
like: "Person": [{"age":"42","name":"John"}]
as object JsonData = "Person": [{"age":"42","name":"John"}];
???
So that i can give this JSON object directly to the DatacontractJSONSerializer
And i could get the data out of it.!
List<Person> people = new List<Person>{
new Person{age = 1, name = "Scott"},
new Person{age = 2, name = "Bill"}
};
string jsonString = ExtensionMethods.JSONHelper.ToJSON(people);
}
}
}
namespace ExtensionMethods
{
public static class JSONHelper
{
public static string ToJSON(this object obj)
{
JavaScriptSerializer serializer = new JavaScriptSerializer();
return serializer.Serialize(obj);
}
public static string ToJSON(this object obj, int recursionDepth)
{
JavaScriptSerializer serializer = new JavaScriptSerializer();
serializer.RecursionLimit = recursionDepth;
return serializer.Serialize(obj);
}
}
}
So,
string jsonString = ExtensionMethods.JSONHelper.ToJSON(people);
Gives a string of : [{},{}]
Empty data structure, Any idea..?

Answer 1

With extension methods, you want to patch your method onto the type that you intend to call that method against. In this case, IEnumerable is a good place to add methods you want to use on a List:
public class Person {
public int age { get; set; }
public string name { get; set; }
}
public static class JSONHelper {
public static string ToJSON(this IEnumerable obj) {
return new JavaScriptSerializer().Serialize(obj);
}
}
void Main() {
List<Person> people = new List<Person> {
new Person() { age = 1, name = "Scott" },
new Person() { age = 2, name = "Bill" }
};
// [{"age":1,"name":"Scott"},{"age":2,"name":"Bill"}]
string json = people.ToJSON();
}
The important distinction is that you should use the extension method against a variable of the type it's defined against. You shouldn't reference the extension method directly.