How to get Hidden Column Value in GridView

Alternative way for 1B, this one is way faster :) :

        protected void btnSelect_Click(object sender, EventArgs e)
        {

            Button btn = (Button)sender;
            DataControlFieldCell dfc = (DataControlFieldCell)btn.Parent;
            GridViewRow gvr = (GridViewRow)dfc.Parent;
            Label lblAddressId = (Label) gvr.FindControl("lblAddressId");

            int iAddressId = (int)  lblAddressId.Text;
            lstAddressId.Add(iAddressId);

        }