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Move the dock panel between zones to see the feature in action.

The DockPanel extension has the capability to load panel content on demand via callbacks. Several content loading modes are available via the following settings of the LoadContentViaCallback property.

  • None - The content is always (initially) rendered inside a dock panel (the default behavior).
  • OnPageLoad - Loading of panel contents starts immediately after an entire page has been loaded.
  • OnFirstShow - Loading of panel contents starts when a dock panel is invoked for the first time.
  • OnDock - Loading of panel contents starts every time a panel has been docked to a dock zone.
  • OnDockStateChange - Loading of panel contents starts every time a panel's dock state has been changed (that is a docked panel starts floating or a floated panel docks to a zone).
  • OnFloating - Loading of panel contents starts every time a panel has been made floated.

Using a delayed load of panel contents, you can enhance the response time of your web page on its initial load. You can also update the content of a dock panel programmatically on demand.

Note that in this example, we purposely pause callback processing on the server side for half a second in order to make the loading panel visible during this time.

Local Copy of this Demo
To inspect the source code for this demo on your machine, you must first install our components via the DevExpress Component Installer.
You can open a local copy of this online demo directly from this webpage (if using v20.2.8, 21.1.4 or higher).
Open CS Solution
The source code files for this demo are installed (by default) in the following directory:
\Users\Public\Documents\DevExpress Demos XX.X\Components\ASP.NET\CS\MVCxDockAndPopupsDemos