As we mentioned in our previous post this functionality is not available. However, you can remove the CellInputUILayer and thus disable inputting any data in the cells. You can achieve that using the following approach.
-First create a new layers builder that derives from the default one, and remove the CellInputUILayer:
ReadOnlyUILayersBuilder : WorksheetUILayersBuilder
-In the constructor of your MainWindow, for example, replace the default builder with the new one:
When the RadSpreadsheet is loaded you will not be able to edit the cells.
Please have in mind that this is only a work-around and genuine read-only functionality is still not available.
All the best,
the Telerik team