ADAdministrator Syncfusion Team November 25, 2003 04:30 AM
Notice in the sample, some cells actually cover several 'standard sized cells". For example, in the tutorial sample, cell 1,1 actually occupies (covers) cells (1,1), (1,2) and (1,3). QueryCoveredRange is the event where these covered ranges are provided on demand. In a non-virtual grid, you can set up covered ranges using grid.CoveredRanges.Add. But in a virtual where you might want a very large number of covered ranges, using this method is not practical. This is the reason for the QueryCoveredRange event.
If you do not need Covered Ranges, then you would not need this handler.