private void isiListBox() { LbxUsername.Items.Clear(); cDatabase db = new cDatabase(); cQuery qr = new cQuery(); string queryUse = string.Empty; if (rbBiroUmum.Checked == true) { queryUse = qr.qSelectUserOpBu(); } else if (rbAkademik.Checked == true) { queryUse = qr.qSelectUserOpAkademik(); } DataTable dtUser = db.selectData(queryUse, '1'); if (dtUser.Rows.Count != 0) { foreach (DataRow row in dtUser.Rows) { LbxUsername.Items.Add(row["username"]); } } dtUser.Clear(); dtUser.Dispose(); }