Using JQuery to call a WebMethod

Question

I am having trouble getting inside my Search WebMethod from my JQuery call. Maybe someone could help to point me in the right direction.

I also packed up everything

Answer 1

To solve a problem like this, the first thing to do is watch it in Firebug.

If you click the "Search" link and watch the POST request/response in Firebug's console, you'll see it's throwing a 500 server error: Invalid JSON Primitive.

The reason for that is because the key/value identifiers in your "data" JSON literal aren't quoted. Line 17 should be:

data: "{'text':'" + search + "'}",

Then, all will work as expected.

Note: The suggested data { test: search } will not work. If you provide jQuery with an actual JSON literal instead of a string, it will convert that into a key/value pair of test=search and POST that instead of the JSON. That will also cause an ASP.NET AJAX ScriptService or PageMethod to throw the Invalid JSON Primitive error.

Answer 2

You need to do the following (C#):

• The WebMethod must be public static
• It must be decorated with the [WebMethod] attribute
• You need a ScriptManager on your .aspx page
• Set the ScriptManager's EnablePageMethods="true"

And here is some sample javascript:

$().ready(function() {
    $(yourDropDownList).change(LoadValues);
});


function LoadValues() {
    PageMethods.YourMethod(arg1, CallSuccess, CallFailed);
}

function CallFailed(result) {
    alert('AJAX Error:' + result.get_message());
}

function CallSuccess(result) {
    //do whatever you need with the result
}