I ma using Telerik.WinControls.Export.GridViewSpreadExport to export data to XLSX.

The CellFormatting event is not called when using RunExportAsync().

It is only called when using RunExport();

Why is that?

I need export with visual settings and Asynchronous, or there a way to export with "RunExport" and show progress bar?

Thanks

Hello, Alejandro,

As it was previously noted, due to performance considerations and in order to decrease the consumed memory the visual settings in RadGridView are not exported when the export operation is run async.

Please refer to the "Exporting Data Asynchronously" section in the following help article which demonstrates how the async spread export feature can be combined with a RadProgressBar control to deliver better user experience: https://docs.telerik.com/devtools/winforms/controls/gridview/exporting-data/spread-export

The progress is not reported when using the RunExport method since it doesn't use a BackgroundWorker which actually reports the progress of the executed work.  
Should you have further questions please let me know.

Regards,
Dess | Tech Support Engineer, Sr.
Progress Telerik