How do I use Validator controls while editing data in the DataGrid?
Yes, you can use the Asp.Net validation controls inside a Datagrid. You’ll need to use a TemplateColumn, and on the TextBoxes (or other controls) in your EditItemTemplate, be sure to give them an ID. Then specify that ID as the ControlToValidate for the validation control.
Refer How to edit data in DataGrid using TemplateColumn?