TExcelFile.VirtualCellRead Event
If you assign this event FlexCel will not load the file into memory when opening a file, allowing you to open very big files using little memory. This event will be called for every value read from the file, and then the value will be discarded, instead of loaded into memory. Look at 'Virtual mode' in the Performance Guide for more information.
Syntax
Unit: FlexCel.Core
property TExcelFile.VirtualCellRead: TVirtualCellReadEventHandler