OBSOLETE - ASPxGridView - Batch Editing - How to use external buttons to update data and enable them only when a row/cell has been changed

UPDATED:

Starting with v16.1, this feature is available out of the box. Please refer to the ASPxGridView, ASPxCardView - Change Save and Cancel buttons' enabled state when an end-user changes a value in BatchEdit mode thread for additional information.

For earlier versions: 

This example demonstrates how to create external Update and Cancel buttons, and enable them only when an end-user edits a cell or a row. 

See Also:
ASPxGridView - Batch Editing - How to show save and cancel buttons only when any row/cell has been changed
MVC Example:
GridView - Batch Editing - How to use external buttons to update data and enable them only when a row/cell has been changed