How to improve performance when hiding ASPxDockPanels with large controls

Even when ASPxDockPanel is hidden, its content will be rendered on a page. The page will contain additional markup with invisible content. To improve performance in this scenario, it is necessary to recreate only the required ASPxDockPanel's content controls on callbacks.

This example illustrates how to implement the aforementioned scenario.
Place two buttons that will show or hide ASPxDockPanel for each ASPxDockPanel on the form. Handle ASPxButton's Init event for all Show and Hide buttons. Apply ASPxButton's client-side Click event and pass ASPxDockPanel's ClientInstanceName, ASPxDockPanel's ID, and a boolean parameter to determine which button is clicked.
On the client side, create a method that will get parameters from the Click event and change a visible state of the required panel. Use ASPxHiddenField to save ASPxDockPanel's visible state. Then, send a callback to the required panel. In the page' Init event, restore a visible state of each ASPxDockPanel on the form on every callback. If a panel is visible, add the required controls onto the panel.