GetActionLinkClass returns the appropriate class type for the action link used with a control. This class is used internally to create an action link object for the control when it has an associated action. The action link links the action to the control client. Each Action link class is designed to link specific properties and event handlers of the action to its client, based on the types of properties the client supports. 

As implemented in TControl, GetActionLinkClass returns the TControlActionLink class type, which associates the ShowHint, Caption, Enabled and Visible properties and the OnClick event handler. Descendants of TControl override this method to specify a descendant of TControlActionLink that handles their configuration of properties and events. 

TControlActionLink 

ActionLink 

Action