>我有一个任务，创建一个餐厅菜单应用程序，允许用户选择饮料、开胃菜、主菜和甜点，每个都有三个选项。我必须使用单选按钮。我应该增加每个人的 mealTotals（每次按下 nextPerson 按钮时，mealTotal 都会添加到下一个人的总数中）以打印整个表格的总计。任何关于我如何为每个人正确增加膳食总增量然后得到一桌总的帮助将不胜感激！
这是主要类：
import javax.swing.BoxLayout;
import javax.swing.JFrame;
public class MenuApp extends JFrame {
// static JFrame frame;
public static void main(String args[]) {
JFrame aFrame = new MenuApp();
aFrame.setVisible(true);
}
public MenuApp() {
setTitle("Leah Thompson's Restaurant App");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Buttons buttonPanel = new Buttons();
buttonPanel.setLayout(new BoxLayout(buttonPanel, BoxLayout.Y_AXIS));
setContentPane(buttonPanel);
pack();
}
}
和按钮类：
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.JTextField;
import java.util.ArrayList;
public class Buttons extends JPanel {
private final JTextField nameField;
String[] drinkChoice = {"Coke", "Beer", "Wine"};
String[] appChoice = {"Soup", "Salad", "Brie"};
String[] entreeChoice = {"Pasta", "Steak", "Burger"};
String[] dessertChoice = {"Tiramisu", "Cheesecake", "Chocolate Cake"};
JRadioButton[] drinkButtons = new JRadioButton[drinkChoice.length];
JRadioButton[] appButtons = new JRadioButton[appChoice.length];
JRadioButton[] entreeButtons = new JRadioButton[entreeChoice.length];
JRadioButton[] dessertButtons = new JRadioButton[dessertChoice.length];
ButtonGroup buttonGroupDrink = new ButtonGroup();
ButtonGroup buttonGroupApp = new ButtonGroup();
ButtonGroup buttonGroupEntree = new ButtonGroup();
ButtonGroup buttonGroupDessert = new ButtonGroup();
JButton mealCost;
JButton nextPerson;
JButton submitOrder;
ArrayList<Double> tableTotal = new ArrayList(0);
double mealTotal = 0;
double mealTotal1 = 0;
public Buttons(){
ActionListener nameEntered = new NameEntered();
add(new JLabel("Name (hit enter after typing name)"));
nameField = new JTextField(10);
add(nameField);
nameField.addActionListener(nameEntered);
ActionListener drinkSelection = new DrinkSelectionChangeMade();
ActionListener appSelection = new AppSelectionChangeMade();
ActionListener entreeSelection = new EntreeSelectionChangeMade();
ActionListener dessertSelection = new DessertSelectionChangeMade();
add(new JLabel("Choose a Drink"));
for (int i = 0; i < drinkChoice.length; i++) {
drinkButtons[i] = new JRadioButton(drinkChoice[i]);
drinkButtons[i].getModel().setActionCommand(drinkChoice[i]);
drinkButtons[i].addActionListener(drinkSelection);
buttonGroupDrink.add(drinkButtons[i]);
add(drinkButtons[i]);
// if (i == 0) {
// mealTotal = mealTotal + 2;
// } else if (i == 1) {
// mealTotal = mealTotal + 3;
// } else {
// mealTotal = mealTotal + 5;
// }
}
add(new JLabel("Choose an Appetizer"));
for (int i = 0; i < appChoice.length; i++) {
appButtons[i] = new JRadioButton(appChoice[i]);
appButtons[i].getModel().setActionCommand(appChoice[i]);
appButtons[i].addActionListener(appSelection);
buttonGroupApp.add(appButtons[i]);
add(appButtons[i]);
// if (i == 0) {
// mealTotal = mealTotal + 6;
// } else if (i == 1) {
// mealTotal = mealTotal + 7;
// } else {
// mealTotal = mealTotal + 8;
// }
}
add(new JLabel("Choose an Entree"));
for (int i = 0; i < entreeChoice.length; i++) {
entreeButtons[i] = new JRadioButton(entreeChoice[i]);
entreeButtons[i].getModel().setActionCommand(entreeChoice[i]);
entreeButtons[i].addActionListener(entreeSelection);
buttonGroupEntree.add(entreeButtons[i]);
add(entreeButtons[i]);
// if (i == 0) {
// mealTotal = mealTotal + 12;
// } else if (i == 1) {
// mealTotal = mealTotal + 20;
// } else {
// mealTotal = mealTotal + 10;
// }
}
add(new JLabel("Choose a Dessert"));
for (int i = 0; i < dessertChoice.length; i++) {
dessertButtons[i] = new JRadioButton(dessertChoice[i]);
dessertButtons[i].getModel().setActionCommand(dessertChoice[i]);
dessertButtons[i].addActionListener(dessertSelection);
buttonGroupDessert.add(dessertButtons[i]);
add(dessertButtons[i]);
// if (i == 0) {
// mealTotal = mealTotal + 7;
// } else if (i == 1) {
// mealTotal = mealTotal + 6;
// } else {
// mealTotal = mealTotal + 5;
// }
}
mealCost = new JButton("Total Cost of Meal");
add(mealCost);
ActionListener mealPrice = new MealCostPressed();
mealCost.addActionListener(mealPrice);
nextPerson = new JButton("Next Person");
add(nextPerson);
ActionListener next = new NextPersonPressed();
nextPerson.addActionListener(next);
submitOrder = new JButton("Submit Order");
add(submitOrder);
ActionListener submit = new SubmitPressed();
submitOrder.addActionListener(submit);
//tableTotal.add(mealTotal);
//add(new JLabel("Your total is: " + mealTotal));
}
private class NameEntered implements ActionListener{
@Override
public void actionPerformed(ActionEvent e){
String name = nameField.getText();
System.out.println(name);
}
}
private class DrinkSelectionChangeMade implements ActionListener {
@Override
public void actionPerformed(ActionEvent e) {
String drink = buttonGroupDrink.getSelection().getActionCommand();
System.out.println(drink + " as a drink");
if(drink == "Coke"){
mealTotal = mealTotal + 1.95;
}
else if(drink == "Beer"){
mealTotal = mealTotal + 2.95;
}
else{
mealTotal = mealTotal + 4.95;
}
}
}
private class AppSelectionChangeMade implements ActionListener {
@Override
public void actionPerformed(ActionEvent e) {
String app = buttonGroupApp.getSelection().getActionCommand();
System.out.println(app + " as an appetizer");
if(app == "Soup"){
mealTotal = mealTotal + 3.95;
}
else if(app == "Salad"){
mealTotal = mealTotal + 4.95;
}
else{
mealTotal = mealTotal + 7.95;
}
}
}
private class EntreeSelectionChangeMade implements ActionListener {
@Override
public void actionPerformed(ActionEvent e) {
String entree = buttonGroupEntree.getSelection().getActionCommand();
System.out.println(entree + " as an entree");
if(entree == "Pasta"){
mealTotal = mealTotal + 11.95;
}
else if(entree == "Steak"){
mealTotal = mealTotal + 19.95;
}
else{
mealTotal = mealTotal + 9.95;
}
}
}
private class DessertSelectionChangeMade implements ActionListener {
@Override
public void actionPerformed(ActionEvent e) {
String dessert = buttonGroupDessert.getSelection().getActionCommand();
System.out.println(dessert + " as a dessert");
if(dessert == "Tiramisu"){
mealTotal = mealTotal + 6.95;
}
else if(dessert == "Cheesecake"){
mealTotal = mealTotal + 5.95;
}
else{
mealTotal = mealTotal + 4.95;
}
tableTotal.add(mealTotal);
}
}
private class NextPersonPressed implements ActionListener{
@Override
public void actionPerformed(ActionEvent e){
//removeAll();
JFrame nextFrame = new MenuApp();
nextFrame.setVisible(true);
System.out.println("Next Customer: ");
}
}
private class MealCostPressed implements ActionListener{
@Override
public void actionPerformed(ActionEvent e){
JOptionPane.showMessageDialog(mealCost, mealTotal);
}
}
private class SubmitPressed implements ActionListener{
@Override
public void actionPerformed(ActionEvent e){
JOptionPane.showMessageDialog(nextPerson, "Thank you for your order. Please Exit Now.");
System.out.println("The total cost for the table is: " + tableTotal);
}
}
}
你需要几样东西...
- 要显示 Tally 的某些组件，声明为实例变量
- 一个
tally变量来维护计数（声明为double），是的，您可以使用long，但我尽量不让您感到困惑。 - 确定已选择/未选择的项目的值的某种方法。
当调用其中一个ActionListener时，您需要确定所选项的值，然后需要确定是否选择了源。
如果选择了该项，则需要将其值添加到tally，如果未选中，则需要减去该值。
然后，您需要设置计数组件的值，可能使用类似 NumberFormat.getCurrencyInstance