The AjaxMethodCallback control provides an easy mechanism for making page or control level method callbacks from an HTML page. Working with both client side and server side logic you can make remote method calls from the client using two-way JSON serialization to access server side content from client pages. Methods are mapped from server to the client with an optional client proxy class that allows making direct method calls to the server. Methods on the server are marked up with a [CallbackMethod] to indicate that the methods are accessible for callbacks. These methods can be implemented on the page, any user control, or custom server control. The latter also allows control developers to dynamically route callbacks to their own controls.

Methods called use JSON to pass data and simple types, hierarchical objects, arrays and IList based classes are supported for two-way transfers. DataSets/DataTables/DataRows are support for downloading only at this time.

This control makes accessing server side content as easy as calling a single proxy method and implementing a single client side handler to receive the result value as a strongly typed object.