RadVirtualGrid uses virtualization for its cells and rows. Since not all data row objects can be visible at the same time, a visual elements (which are large objects) are created only for the currently visible rows/cells in the RadVirtualGrid. These visual elements are reused during scrolling, filtering and other operations with the grid, meaning dramatically improved performance and memory footprint as only a small number of visual items are created.
Because of the virtualization you cannot access UI elements at design time or directly by using the Element tree or a property. Instead, you have to use formatting events. These events in RadVirtualGrid are CellFormatting for all cells and RowFormatting for all rows. Detailed information about these events can be found in the following articles: