The UI Dock Controls for ASP.NET AJAX are designed to help developers manage multiple windows and the web page layout by creating a movable content placeholder in ASP.NET web application. The created placeholder can be dragged around the web page, docked into docking zone, collapsed into minimized state, expanded and pinned in specific place. Besides, the customized page layout can be saved into file or database for later reloading.

The Dock Controls for ASP.NET AJAX contain three major controls, which are PerDock Control, PerDockZone Control and PerDockLayout. And in this section, we will briefly illustrate each of these three dock controls.

• PerDock Control: the PerDock refers to a movable content placeholder, which can be freely dragged, pinned, expanded, docked and minimized in the web page. This PerDock Control has a Title Bar element for displaying title and commands and a Content area for showing content.
• PerDockZone: the PerDockZone is a static placeholder where you can dock one or more PerDock controls. Its element Placeholder will show where the PerDock Control will be docked.
• PerDockLayout: the PerDockLayout Control is used to manage the layout of the PerDock controls in the web page. Although this control can not be seen visually, developers have to place all the PerDockZone and PerDock controls into this PerDockLayout control for the layout management. What should be noted here is that the layout of web page will not be preserved for later reloading if you do not place the PerDockZone and PerDock controls into this PerDockLayout control.

In this section, we will briefly list the actions that the dock controls has enabled the users to do, including:

• Allow developers to add custom commands to the PerDock Control;
• Enable users to customize the settings and format of docking zones programmatically;
• Design the template of TitleBar element;
• Modify the feel-and-look style and appearance of the dock controls;
• Customize the behavior by applying server-side events and client-side APIs in response to the actions performed by the end users;
• Offer mobile support.