public DataTable GetData() { DataTable dt = new DataTable(); cmd.CommandText = "SELECT * From tb_KhacHang"; cmd.CommandType = CommandType.Text; cmd.Connection = con.Connection; try { con.OpenConn(); SqlDataAdapter sda = new SqlDataAdapter(); sda.Fill(dt); con.CloseConn(); } catch (Exception ex) { string mex = ex.Message; cmd.Dispose(); con.CloseConn(); } return(dt); }