GridVew1_RowDataBind GridView1.DataKeys[e.Row.RowIndex].Values[5].ToString();

 

foreach (GridViewRow t in GridView2.Rows)                    {                        if (((CheckBox)t.FindControl("CheckBox1")).Checked)                        {                            ID = GridView2.DataKeys[t.RowIndex].Values[0].ToString();                            //Num = Int32.Parse(GridView2.DataKeys[t.RowIndex].Values[4].ToString());                            Num = Int32.Parse(((TextBox)(t.FindControl("tbNum"))).Text);                            DubtVerificationAppDetailModify(ID, Num, this.lblMainID.Text);                        }                    }