private void chkItems_CheckedChanged(object sender, EventArgs e)
 {
     foreach (DataGridViewRow row in dgvFirmaListele.Rows)
     {
         DataGridViewCheckBoxCell chk = (DataGridViewCheckBoxCell)row.Cells[1];
         if (chk.Selected == true)
         {
             seciliFirma     = Convert.ToInt32(dgvFirmaListele.SelectedRows[0].Cells[1].Value);
             _tedarikciFirma = _tedarikciFirmaService.BirTedarikciFirmaGetirService(seciliFirma);
             chk.Selected    = false;
         }
         else
         {
             chk.Selected = true;
         }
     }
 }