0

请您检查下面我的代码有什么问题。这是一个简单的点餐系统，需要用户输入顾客姓名、收银员姓名、是堂食还是外卖以及密码。每次我在组合框中单击一次餐点，我选择的餐点就会翻倍

例如我点击了 PM3 它显示：

您的订单是/是： PM3（猪肉烧烤 4 件）
PM3（猪肉烧烤 4 件）

但应该是：您的订单是/是：PM3（猪肉烧烤 4 件）

顺便说一句，我有 2 个课程，我将在下面显示他们的代码。

课程代码：

import java.util.Scanner;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

 public class Show{

  private static String z  = "";
  private static String w  = "";
  private static String x  = "";
  JComboBox combo;
  private static String a  = "";

 public Show(){
 String mgaPagkainTo[] = {"PM1 (Paa/ Spicy Paa with Thigh part)","PM2 (Pecho)","PM3 (Pork Barbeque 4 pcs.)","PM4 (Bangus Sisig)","PM5 (Pork Sisig)","PM6 (Bangus Inihaw)","SM1 (Paa)","SM2 (Pork Barbeque 2 pcs.)","Pancit Bihon","Dinuguan at Puto","Puto","Ensaladang Talong","Softdrinks","Iced Tea","Halo-Halo","Leche Flan","Truon Split"};
 JFrame frame = new JFrame("Mang Inasal Ordering System");
 JPanel panel = new JPanel();
 combo = new JComboBox(mgaPagkainTo);
 combo.setBackground(Color.gray);
 combo.setForeground(Color.red);
 panel.add(combo);
 frame.add(panel);
    combo.addItemListener(new ItemListener(){
    public void itemStateChanged(ItemEvent ie){
        String str = (String)combo.getSelectedItem();
        a = str;
        ShowOrder messageOrder1 = new ShowOrder();
        messageOrder1.ShowOrderPo();
       }
    });

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(300,250);
    frame.setVisible(true);
  }

   public static void main(String[] args) {
   Scanner inp = new Scanner(System.in);
   boolean ulitinMoPows = true;
   boolean tryAgain = true;

    System.out.print("\nInput Customer Name: ");
    String customerName = inp.nextLine();
    w = customerName;
    System.out.print("\nInput Cashier Name: ");
    String user = inp.nextLine();
    z = user;
  do{
    System.out.print("\nInput either Dine In or Take Out: ");
    String dInDOut = inp.nextLine();
    x = dInDOut;
        if (x.equals("Dine In") || x.equals("Take Out")){
         System.out.print("");
         ulitinMoPows = false;
         }
        else{
         JOptionPane.showMessageDialog(null, "Try again! Please input Dine In or Take Out only!","Error", JOptionPane.ERROR_MESSAGE);
             ulitinMoPows = true;
             System.out.print ("\f");
            }
 }while(ulitinMoPows);
 do{
    System.out.print("\nInput password: ");
    String pass = inp.nextLine();
    if(pass.equals("admin")){
        ShowOrder messageShowMenu = new ShowOrder();
        messageShowMenu.ShowMenu();
        tryAgain = false;
    }
    if(!pass.equals("admin")){
        JOptionPane.showMessageDialog(null, "Try again! Invalid password!","Error Logging-In", JOptionPane.ERROR_MESSAGE);
    tryAgain = true;
     System.out.print ("\f");
    }
}while(tryAgain);
Show j = new Show();
    }

  public static String kuhaOrder()
{
  return a;
}

public static String kuhaUserName()
{
return z;
}

public static String kuhaCustomerName()
{
return w;
}

public static String kuhaSanKainPagkain()
{
return x;
}  
}

ShowOrder 类的代码：

public class ShowOrder {

public void ShowMenu(){
    String user = Show.kuhaUserName();
    System.out.print("\n\n\t\tCashier: " +user);
    String dInDOut = Show.kuhaSanKainPagkain();
    System.out.print("                          "+dInDOut);
    String customerName = Show.kuhaCustomerName();
    System.out.print("\n\t\tCustomer Name: " +customerName);
    System.out.print("\t\t\t\n\nYour order is/ are: ");
}


public void ShowOrderPo() {
    String order = Show.kuhaOrder();
    System.out.print("\t\t\t\t\n " +order);

}
}
4

2 回答 2

4

您的ItemListener代码将针对选定和取消选定状态更改执行两次。您需要检查侦听器中的状态更改状态：

if (ie.getStateChange() == ItemEvent.SELECTED) {
  ...

或者干脆使用一个ActionListener是你不想检查状态变化。

请参阅：如何编写项目侦听器

于 2013-02-25T11:12:06.607 回答
2

用户更改组合框中的选择。因此，第一个 ItemEent 被触发以告知先前选择的项目已被取消选择，第二个 ItemEent 被触发以表示新选择的项目已被选择。

我会使用 ActionListener 而不是 ItemListener。

于 2013-02-25T11:12:30.933 回答