Forms Data Controls :: Get Cell Values In A GridView After Dynamically Adding Validation Controls?

So I have a gridview control and I am binding it's datasource dynamically base on a dropdownlist. The gridview contains autogenerated columns with auto generated edit buttons. The datasource binded to the gridview is IQueryable<T> where T will be different for different datasource.

My detail problem is below:

A GridView binded to datasource dynamically with all autogenerated columns. When user click edit link, it will display value in autogenerated textboxes.

When user click update link, I am able to capture the user entered value in the textboxes in RowUpdating event, then pass those values to Linq update function to update the database. Now, the problem begin when I try to dynamically add validation controls to each editing row. In RowDataBound event, I am checking the editrowindex then adding validation control to gridview cell and pointing to cell.controls[0] which is the textbox control when the row is in edit mode, I am dynamically setting the textbox control id so that the validation control can set controltovalidate property. The validation control works, but the updating function is setting everything on the grid to empty string.

I am check the textbox text value in the loop, which returns "" for all cells except the id column. It was returning the correct value before I add the validation control. I guess since I added the validation control on rowdatabound event, will it rerender it's own autogenerated textbox in edit mode so that the text value of textbox no longer available in rowupdating event?

Is there a better or correct way to get the cell textbox value? I am using ((TextBox)dc.Controls[0]).Text where dc is DataControlFieldCell in rowupdating event.