Returning Json In Asp.net Webservice

In my application,we use the prototype1.4.2 in the page. And we need the tree view which support lazy load(make a ajax request and add the data from the server to the node),then I

Solution 1:

you can use jquery to do an Ajax call.

$.ajax({
        type: "POST",
        contentType: "application/json; charset=utf-8",
        url: "webServiceUrl/MethodName",
        data: "{Id: '" + id + "'}",
        dataType: "json",
        success: loadSucceeded,
        error: loadFailed,
        async: true
    });

functionloadSucceeded(result, status)
{
    var data = result.d;
}

functionloadFailed(result, status)
{
}

Note that it is not necessarily to return a string, you can return a list of object.

[WebService(Namespace = "http://microsoft.com/webservices/";
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
[ScriptService]
publicclassUtilService: WebService 
{
    [WebMethod]
    publicList<string> loadData(id) {
      //some logic according the idreturnnew List<string>(){"data"};
    }
}