You can have a look at the Mixed Selection
article of the RadGridView documentation
if you have not done so already. Note that when Mixed selection is enabled, you need to click in the indicator column of RadGridView to select a full row.
Regarding the column selection, please find the Column Selection
demo from the SDK Examples Browser
and let me know if it works for you.
Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Feedback Portal
and vote to affect the priority of the items