PageMethod与Ajax异步调用

I am new asp.net and want to call server side method from java script. For that I can do this using ajax call and PageMethod.

Now my question is which one is better to use?

$.ajax({})

Or

PageMethods.FunctionName(Parameter);

No one can tell better than Dave Ward

http://encosia.com/using-jquery-to-directly-call-aspnet-ajax-page-methods/

Page methods are much more openly accessible. The relative unimportance of EnablePageMethods is a nice surprise.

$.ajax({
  type: "POST",
  url: "PageName.aspx/MethodName",
  data: "{}",
  contentType: "application/json; charset=utf-8",
  dataType: "json",
  success: function(msg) {
    // Do something interesting here.
  }
});

if you have already put Ajax scrip manager. you can user any method. but if you have not put script manager i suggest you should go for Ajax asynchronous call

Page methods are much more openly accessible.and it is not good idea to put script manager just for web method calling