private void btnTable_Click(object sender, EventArgs e) { Button b = sender as Button; if (b == null) { return; } TableOrder to = new TableOrder(Convert.ToInt32(b.Tag)); /////// using (var TableOrder = new TableOrder(Convert.ToInt32(b.Tag))) { var result = to.ShowDialog(); if (result == DialogResult.OK) { ApplicationDbContext cntxt = new ApplicationDbContext(); var c = cntxt.ByTables.FirstOrDefault(z => z.TableID == (int)b.Tag); if (c.check == 1) { b.BackColor = Color.Red; b.ForeColor = Color.White; } else if (c.check == 0) { b.BackColor = Color.Azure; b.ForeColor = Color.Black; } } } ////// }