//查询 private void btnQuery_Click(object sender, EventArgs e) { switch (cmbQuery.SelectedIndex) { case 0: using (var db = new OrderContext()) { bindingSource1.DataSource = orderService.Orders; //bindingSource1.ResetBindings(false); } break; case 1: int.TryParse(QueryText, out int id); bindingSource1.DataSource = orderService.QueryById(id); break; case 2: bindingSource1.DataSource = orderService.QueryByCustomerName(QueryText); break; case 3: bindingSource1.DataSource = orderService.QueryByGoodsName(QueryText); break; case 4: float.TryParse(QueryText, out float totalPrice); bindingSource1.DataSource = orderService.QueryByTotalAmount(totalPrice); break; } bindingSource1.ResetBindings(false); }