Custom ASP.NET AJAX controls allow specialized functionality to be added into an application that can be reused over and over. In this chapter, you’ve seen how to create a client-side ASP.NET AJAX control capable of generating custom output. Core steps that should be followed when creating controls were discussed, including making a constructor, using the prototype design pattern, initializing controls, and disposing of control resources. You’ve also seen how control events can be hooked up to event handlers and how controls can be created and used in an application.
This chapter also discussed how to create custom server-side ASP.NET AJAX controls. Server-side controls can be created to extend existing controls, or new controls can be built from the ground up that add unique features and functionality. You’ve seen how the IScriptControl interface can be used and how scripts and properties used by a client-side script can be referenced and used. In addition to examining these topics, you’ve also seen how a custom control can be registered as a script control with the ScriptManager. Finally, you’ve seen how a custom server-side control can be defined and used in a page.