How to get Hidden Value in GridView

Once a column's Visible property is set to Hidden, no longer can we access it, since it returns blank.

To overcome that we can do 4 things
1) Use DATAKEY property and to hidden column ID.
GridView.DataKeys[0].Value.ToString();
 
2) Use TEMPLATE COLUMN and make it visible and access the values using FindControl.
Label lblID = (Label) GridView.Rows[0].FindControl("lblMyId");

3) Using a sylesheet ,set the property display=none, and can get the values.
GridView.Rows[0].Cell[0].Text

4) After databinding, set the visible property of the column.
   GridView.Columns[0].Visible = false;


http://www.dotnetspark.com/kb/1937-how-to-get-hidden-column-value-gridview.aspx