Hi,
EO.Grid is much more powerful but it is also a bit more complex than the standard GridView. Specifically it allows you to make multiple changes before your page is posted back to the server (for example, you can modify multiple cells and then post back all the changes back to the server with one button click). Most standard validator controls work with a single piece of input data. For example, RequiredValidator verifies whether a single input field is empty. This does not work with EO.Grid because potentially multiple places need to be validated.
However you can use a CustomValidator to validate all the data in the Grid at once. To do so simply handle your CustomValidator's Validate event to check all the Grid cells you want to check. You can also provide a client side JavaScript validation function to check all cell values on the client side. You will need to use the Grid’s client side JavaScript API to access the cell data if you choose to do so:
http://doc.essentialobjects.com/library/1/clientapi_howto.aspxIf you wish to validate on each cell right after user edited the cell, you will need to handle the Grid's ClientSideAfterEdit event. Here is a working example demonstrating how to do this:
http://demo.essentialobjects.com/Default.aspx?path=Grid\_i1\_i23You can take a look of the sample source code to see how it works.
Hope this helps. Please feel free to let us know if you have any more questions.
Thanks!