Occurs when a callback for server-side processing is initiated.
The BeginCallback event's data class is ASPxClientBeginCallbackEventArgs. The following properties provide information specific to this event:
|command||Gets a command name that identifies which client action forced a callback to occur.|
The BeginCallback event, together with the ASPxClientSpreadsheet.EndCallback event, can be used to perform specific client-side actions (for example, to display and hide an explanatory picture) while a callback is being processed on the server side.
The spreadsheet sends most requests via internal handler and does not raise the BeginCallback and EndCallback events for performance reasons. It is recommend to use server events in the spreadsheet because the major work with a document is accomplished on the server.