jQuery.getJSON Call ASP.NET method

Question

I have jQuery code to get JSON from the server:

 $(document).ready(function () {
            $.getJSON('Default2.aspx/GetPerson', { 'firstname': 'brian', 'lastname': 'lee' }, function (response) {
                alert(response.Age);
            });    
        });

Default2.aspx code :

    [WebMethod]
    [ScriptMethod(ResponseFormat = ResponseFormat.Json)]
    public static String GetPerson(String firstname, String lastname)
    {
        Person p = new Person(firstname, lastname);
        return "{\"Age\":\"12\"}";
    }

The question is :

Why GetPerson method is not called from my script? I attach the debugger in GetPerson but it seems doesn't called.

Any help would be appreciate!

Answer 1

WebMethods by default respond to POST rather than GET requests.

$.ajax({
    type: 'POST',
    url: 'Default2.aspx/GetPerson',
    dataType: 'json',
    // ...
});

And, the request format should be JSON as well to match the ResponseFormat:

// ...
    data: JSON.stringify({ 'firstname': 'brian', 'lastname': 'lee' }),
    contentType: 'application/json'

---

Alternatively, a ScriptMethod can be configured to use GET instead:

[ScriptMethod(ResponseFormat = ResponseFormat.Json, UseHttpGet = true)]

Though, contentType still needs to be set for it, so $.getJSON() can't be used:

$.ajax({
    type: 'GET',
    url: 'Default2.aspx/GetPerson',
    dataType: 'json',
    contentType: 'application/json',
    // ...
});

And, data will be URL-encoded, but each value will need to be JSON-encoded before that:

// ...
    data: {
        firstname: JSON.stringify('brian'),
        lastname: JSON.stringify('lee')
    }

---

Also note that ScriptMethods will wrap their response in a { "d": ... } object. And, since the return value is a String, the value of "d" be that same unparsed String:

// ...
    success: function (response) {
        response = JSON.parse(response.d);
        alert(response.Age);
    }