Java 总变量赢得'；t更新
我是Java新手，所以我仍在努力理解如何正确地更新变量。我正在创建一个作为餐厅菜单的程序。列出的菜单项将出现在左侧，一旦用户检查一个项目并单击右侧按钮，该项目将出现在右侧，该项目的价格应添加到总变量中；然而，这是行不通的。有一些不必要的代码，但是如果可以的话，请忽略这些和一些注释。多谢各位Java 总变量赢得'；t更新,java,eclipse,cumulative-sum,Java,Eclipse,Cumulative Sum,我是Java新手，所以我仍在努力理解如何正确地更新变量。我正在创建一个作为餐厅菜单的程序。列出的菜单项将出现在左侧，一旦用户检查一个项目并单击右侧按钮，该项目将出现在右侧，该项目的价格应添加到总变量中；然而，这是行不通的。有一些不必要的代码，但是如果可以的话，请忽略这些和一些注释。多谢各位 package finalproject; import java.awt.event.*; import java.awt.*; import javax.swing.*; public class
package finalproject;
import java.awt.event.*;
import java.awt.*;
import javax.swing.*;
public class MenuFrame extends JFrame implements ActionListener {
final double BURGER_PRICE = 6.24;
final double FISH_PRICE = 13.78;
final double SOUP_PRICE = 4.49;
final double CHICKEN_PRICE = 11.36;
final double SALAD_PRICE = 5.60;
final double FRIES_PRICE = 3.24;
JPanel menuPanel = new JPanel(); //Panel to place the menu in, which will be on left side
JPanel buttonPanel = new JPanel(); //Panel to place buttons in, which will be in center
JPanel orderPanel = new JPanel(); //Panel to place order menu in, which will be on right side
JLabel menuLabel = new JLabel("Menu"); //Label for the menu
JLabel orderLabel = new JLabel("Your Order"); //Label for the user's order
JCheckBox burger = new JCheckBox("Burger: $6.24", false); //Burger check box
JCheckBox fish = new JCheckBox("Fish: $13.78", false); //Fish check box
JCheckBox soup = new JCheckBox("Soup: $4.49", false); //Soup check box
JCheckBox chicken = new JCheckBox("Chicken: $11.36", false); //Chicken check box
JCheckBox salad = new JCheckBox("Salad: $5.60", false); //Salad check box
JCheckBox fries = new JCheckBox("Fries: $3.24", false); //Fries check box
JButton rightButton = new JButton("->"); //Button to move items from left to right
JButton leftButton = new JButton("<-"); //Button to move items from right to left
JLabel skipPosition = new JLabel(""); //Label used to skip position in GridLayout
static double totalPrice = 0; //Total price of order
Font titleFont = new Font("Times New Roman",Font.BOLD,20);
JLabel totalLabel = new JLabel(""); //total label
public MenuFrame() {
setLayout(new GridLayout(0,3));
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(1055, 275); //Set size of Menu Frame
menuPanel.setLayout(new GridLayout(0,3)); //Setting Menu's layout to GridLayout
//Box buttonBox = Box.createVerticalBox(); //Creating box object for button panel
buttonPanel.setLayout(new GridLayout(8,3));
orderPanel.setLayout(new GridLayout(0,3)); //Setting Order's layout to FlowLayout
menuLabel.setFont(titleFont);
orderLabel.setFont(titleFont);
//Adding menu items to Menu
menuPanel.add(new JLabel(""));
menuPanel.add(menuLabel);
menuPanel.add(new JLabel(""));
menuPanel.add(burger);
menuPanel.add(fish);
menuPanel.add(soup);
menuPanel.add(chicken);
menuPanel.add(salad);
menuPanel.add(fries);
//Adding buttons to Box
//buttonBox.add(rightButton);
//buttonBox.add(Box.createVerticalStrut(100));
//buttonBox.add(leftButton);
//Adding box to button panel
//buttonPanel.add(buttonBox);
//Adding "Your Order" label to Order. Items will be subsequently added or removed
orderPanel.add(new JLabel(""));
orderPanel.add(orderLabel);
orderPanel.add(new JLabel(""));
totalLabel.setText("$" + totalPrice);
buttonPanel.add(new JLabel(""));
buttonPanel.add(new JLabel(""));
buttonPanel.add(new JLabel(""));
buttonPanel.add(new JLabel(""));
buttonPanel.add(new JLabel(""));
buttonPanel.add(new JLabel(""));
buttonPanel.add(new JLabel(""));
buttonPanel.add(new JLabel(""));
buttonPanel.add(new JLabel(""));
buttonPanel.add(new JLabel(""));
buttonPanel.add(rightButton);
buttonPanel.add(new JLabel(""));
buttonPanel.add(new JLabel(""));
buttonPanel.add(leftButton);
buttonPanel.add(new JLabel(""));
buttonPanel.add(new JLabel(""));
buttonPanel.add(new JLabel(""));
buttonPanel.add(new JLabel(""));
buttonPanel.add(new JLabel(""));
buttonPanel.add(new JLabel(""));
buttonPanel.add(new JLabel(""));
buttonPanel.add(new JLabel(""));
buttonPanel.add(new JLabel(""));
buttonPanel.add(new JLabel(""));
buttonPanel.add(totalLabel);
//Adding action listener to rightButton and leftButton
rightButton.addActionListener(this);
leftButton.addActionListener(this);
add(menuPanel);
add(buttonPanel);
add(orderPanel);
}
@Override
public void actionPerformed(ActionEvent e) {
Object source = e.getSource();
//If right button was clicked
if(source == rightButton) {
//if burger was selected and is in the menu panel
if(burger.isSelected() && burger.getParent() == menuPanel) {
//Move burger from menu to order, deselect burger, and add 6.24 to total price
menuPanel.remove(burger);
orderPanel.add(burger);
burger.setSelected(false);
totalPrice += BURGER_PRICE;
}
//if fish was selected and is in the menu panel
if(fish.isSelected() && fish.getParent() == menuPanel) {
//Move fish from menu to order, deselect fish, and add 13.78 to total price
menuPanel.remove(fish);
orderPanel.add(fish);
fish.setSelected(false);
totalPrice += FISH_PRICE;
}
//if soup was selected and is in the menu panel
if(soup.isSelected() && soup.getParent() == menuPanel) {
//Move soup from menu to order, deselect soup, and add 4.49 to total price
menuPanel.remove(soup);
orderPanel.add(soup);
soup.setSelected(false);
totalPrice += SOUP_PRICE;
}
//if chicken was selected and is in the menu panel
if(chicken.isSelected() && chicken.getParent() == menuPanel) {
//Move chicken from menu to order, deselect chicken, and add 11.36 to total price
menuPanel.remove(chicken);
orderPanel.add(chicken);
chicken.setSelected(false);
totalPrice += CHICKEN_PRICE;
}
//if salad was selected and is in the menu panel
if(salad.isSelected() && salad.getParent() == menuPanel) {
//Move salad from menu to order, deselect salad, and add 5.60 to total price
menuPanel.remove(salad);
orderPanel.add(salad);
salad.setSelected(false);
totalPrice += SALAD_PRICE;
}
//if fries was selected and is in the menu panel
if(fries.isSelected() && fries.getParent() == menuPanel) {
//Move fries from menu to order, deselect fries, and add 3.24 to total price
menuPanel.remove(fries);
orderPanel.add(fries);
fries.setSelected(false);
totalPrice += FRIES_PRICE;
}
}
//if left button was clicked
if(source == leftButton) {
//if burger was selected and is in the order panel
if(burger.isSelected() && burger.getParent() == orderPanel) {
//Move burger from order to menu, deselect burger, and remove 6.24 from total price
orderPanel.remove(burger);
menuPanel.add(burger);
burger.setSelected(false);
totalPrice -= BURGER_PRICE;
}
//if fish was selected and is in the order panel
if(fish.isSelected() && fish.getParent() == orderPanel) {
//Move fish from order to menu, deselect fish, and remove 13.78 from total price
orderPanel.remove(fish);
menuPanel.add(fish);
fish.setSelected(false);
totalPrice -= FISH_PRICE;
}
//if soup was selected and is in the order panel
if(soup.isSelected() && soup.getParent() == orderPanel) {
//Move soup from order to menu, deselect soup, and remove 4.49 from total price
orderPanel.remove(soup);
menuPanel.add(soup);
soup.setSelected(false);
totalPrice -= SOUP_PRICE;
}
//if chicken was selected and is in the order panel
if(chicken.isSelected() && chicken.getParent() == orderPanel) {
//Move chicken from order to menu, deselect chicken, and remove 11.35 from total price
orderPanel.remove(chicken);
menuPanel.add(chicken);
chicken.setSelected(false);
totalPrice -= CHICKEN_PRICE;
}
//if salad was selected and is in the order panel
if(salad.isSelected() && salad.getParent() == orderPanel) {
//Move salad from order to menu, deselect salad, and remove 5.60 from total price
orderPanel.remove(salad);
menuPanel.add(salad);
salad.setSelected(false);
totalPrice -= SALAD_PRICE;
}
//if fries was selected and is in the order panel
if(fries.isSelected() && fries.getParent() == orderPanel) {
//Move fries from order to menu, deselect fries, and remove 3.24 from total price
orderPanel.remove(fries);
menuPanel.add(fries);
fries.setSelected(false);
totalPrice -= FRIES_PRICE;
}
}
//Make changes appear
repaint();
revalidate();
}
public static void main(String[] args) {
//Instantiating MenuFrame object
MenuFrame menuFrame = new MenuFrame();
//Making frame visible
menuFrame.setVisible(true);
}
包最终项目；
导入java.awt.event.*；
导入java.awt.*；
导入javax.swing.*；
公共类MenuFrame扩展JFrame实现ActionListener{
最终双汉堡价格=6.24；
最终双鱼价格=13.78；
最终双汤价格=4.49；
最终双鸡价格=11.36；
最终双色拉价格=5.60；
最终双份薯条价格=3.24；
JPanel menuPanel=new JPanel（）；//用于放置菜单的面板，位于左侧
JPanel buttonPanel=new JPanel（）；//用于放置按钮的面板，位于中间
JPanel orderPanel=new JPanel（）；//放置订单菜单的面板，位于右侧
JLabel menuLabel=新的JLabel（“菜单”）；//菜单的标签
JLabel orderLabel=new JLabel（“您的订单”）；//用户订单的标签
JCheckBox-burger=新的JCheckBox（“汉堡：$6.24”，false）；//汉堡复选框
JCheckBox fish=newjcheckbox（“fish:$13.78”，false）；//fish复选框
JCheckBox-soup=newjcheckbox（“soup:$4.49”，false）；//soup复选框
JCheckBox chicken=newjcheckbox（“chicken:$11.36”，false）；//chicken复选框
JCheckBox沙拉=新的JCheckBox（“沙拉：$5.60”，false）；//沙拉复选框
JCheckBox fries=新的JCheckBox（“fries:$3.24”，false）；//fries复选框
JButton rightButton=newjbutton（“->”）；//从左向右移动项目的按钮
JButton leftButton=new JButton（“totalPrice）”如果您不分配它，它不会被设置到文本字段中。
在刷新之前，请先执行以下操作：
totalLabel.setText("$" + totalPrice);
变量更新正确，只是您没有重新设置TotalAbel文本
if(burger.isSelected() && burger.getParent() == menuPanel) {
//Move burger from menu to order, deselect burger, and add 6.24 to total price
menuPanel.remove(burger);
orderPanel.add(burger);
burger.setSelected(false);
totalPrice += BURGER_PRICE;
totalLabel.setText("$" + totalPrice); <<<<<< Add this to all of items
}
if（burger.isSelected（）&&burger.getParent（）==menuPanel）{
//将汉堡从菜单移动到订单，取消选择汉堡，并将6.24添加到总价中
menuPanel.移除（汉堡）；
orderPanel.add（汉堡）；
汉堡包（假）；
总价+=汉堡价格；
TotalAbel.setText（“$”+总价）；告诉我们什么实际不起作用？不打印？无法设置变量？请提供更多详细信息1.如果您是Java新手，您可能不应该尝试编写GUI。2.您确实需要限制此处的代码量，以便只包含相关代码。此处的代码太多，而且涉及异步内容、侦听器等这确实增加了复杂性。请先在一些关键位置放置System.out.println
，以确保您得到了应该添加到总数中的代码。因此，如果您认为应该选择汉堡，请在应该添加的if
中放置println
。如果您没有找到，请尝试其他方法System.out.printlns
查看source==rightbutton
是否为真，是否调用了actionPerformed
等等。基本上，出错的方式太多了。你需要自己进行一些调试。一件明显奇怪的事情是：你所有的字段都是非静态的，除了你的总值之外。那就是我完全同意其他的评论：虽然你的技能处于如此基本的水平，但请不要去面对如此复杂的挑战。从小事做起，理解并掌握所有的基础知识；然后去做UI方面的事情。写下数百行复杂的代码……这让你难以理解nd…不是你应该扔给别人的东西。。。