我有期末考试,我的教授强调的重点之一是组合框。我已经完成了家庭作业,我也通过这里发布了一个问题,我明白了。他希望我们遵循这种模式:ComboBox code correct? .
现在,我开始为自己的练习寻找其他问题,但遇到了一些麻烦。这有点像我的家庭作业,但内容更多。问题:
A university has the following dormitories:
- Allan Hall: $1,500 per semester
- Pike Hall: $1,600 per semester
- Fathering Hall: $1,200 per semester
- University Suites: $1,800
The university also offers the following meal plans:
- 7 meals per week: $560 pr semester
- 14 meals per week: $ 1,095
- Unlimited meals: $1,800 per semester
Create an application with 2
ComboBox
es. One should hold the names of the dorms and the other should hold the meal plans. The user should select a dorm and a meal plan and the application should show the total charges.
我开始编写一些代码,但我不确定如何将两个组合框一个接一个地放置,然后如何为也是如此。
这是代码;我知道这是一团糟。谁能告诉我如何正确地写这个?我只是想做好准备。请耐心等待,感谢您的耐心和帮助。我的代码(我将在编译器出现红色的部分代码上放置 4 ****
):
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class DormAndMealPlanCalc extends JFrame
{
private JPanel dormPanel;
private JPanel selectedDormPanel;
private JComboBox DormBox;
private JLabel label;
private JTextField selectedDorm;
private String[] dorm = {"Allen Hall: $1,500 per semester","Pike Hall: $1,100 per" +
"semester","Fathering Hall: 1,200 per semester","Universty Suites: $1,800"};
public void ComboBoxWindow1()
{
**super("Dorm plan");** wrong placement?
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new BorderLayout());
buildDormPanel();
**buildSelectedDormPanel;** Variable error
add(dormPanel,BorderLayout.CENTER);
add(selectedDormPanel, BorderLayout.SOUTH);
pack();
setVisible(true);
}
private void buildDormPanel()
{
dormPanel = new JPanel();
DormBox = new JComboBox(dorm);
DormBox.addActionListener(new ComboBoxListener());
dormPanel.add(DormBox);
}
private void buildSelectedDormPanel()
{
selectedDormPanel = new JPanel();
label = new JLabel("You selected: ");
selectedDorm = new JTextField(10);
selectedDorm.setEditable(false);
selectedDormPanel.add(label);
selectedDormPanel.add(selectedDorm);
}
private class ComboBoxListener implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
String selection = (String) DormBox.getSelectedItem();
selectedDorm.setText(selection);
}
}
public void main(String[] args)
{
**new ComboBoxWindow2();**
}
}
private JPanel mealPanel;
private JPanel selectedMealPanel;
private JComboBox MealBox;
private JLabel label1;
private JTextField selectedMeal;
private JButton calcbutton;
private String[] Meal = {"7 meals per week: $560 per semester","14 meals per week:" +
"$1,095 per semester","Unlimited meals: $1,500 per semester"};
public void ComboBoxWindow()
{
**super("Meal plan");**
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new BorderLayout());
buildMealPanel();
**BuildselectedMealPanel;** variable problem
add(mealPanel,BorderLayout.CENTER);
add(selectedMealPanel, BorderLayout.SOUTH);
pack();
setVisible(true);
}
private void buildMealPanel()
{
mealPanel = new JPanel();
MealBox = new JComboBox(meal);
MealBox.addActionListener(new ComboBoxListener());
mealPanel.add(MealBox);
**calcbutton = new JButton("Calculate");** syntax/token error
}
calacbutton.addActionListener(new calcbuttonListener);
private void buildSelectedMealPanel()
{
selectedMealPanel = new JPanel();
label = new JLabel("You selected: ");
selectedMeal = new JTextField(10);
selectedMeal.setEditable(false);
selectedMealPanel.add(label);
selectedMealPanel.add(selectedDorm);
}
private class ComboBoxListener1 implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
String str;
String selection = (String) DormBox.getSelectedItem();
selectedDorm.setText(selection);
**JOptionPane.showMessageDialog('Total is' + dorm + meal);** argument error
}
}}
最佳答案
OP 的代码不是有效的 Java,如果不首先解释如何在 OOP 中编码,就无法使其工作。
很多琐碎的错误。
1)函数调用后没有()
buildSelectedDormPanel;
-> buildSelectedDormPanel();
2) 类/c-tors 的错误方法
public void ComboBoxWindow1() {
应该是,比如
class ComboBoxWindow1 extends JFrame {
public void ComboBoxWindow1() {
等,甚至使用匿名类覆盖,即
JFrame f = new JFrame() {
等等
3) ComboBox 是一个通用类型,所以请不要使用原始版本 - 请改用 ComboBox
4) 在需要的地方添加@Override注解
5) 注意你拼写的大小写......你将小写字母与小写字母和小写字母混合使用
6) 修复你的括号(不仅是圆括号,而且整个代码中的圆括号也错位了)
7) 你把 ""误认为是字符串而把 '' 误认为是字符
8) 如果您想评论您的代码(即代码中的错误,请使用 COMMENT/* */或//,而不是我在尝试正确格式化您的代码之前必须删除的一些星号,
9) 差距和错误太多,一些未使用的变量,一些字段(全局变量?猜不出意图)没有任何明确的类附件 - 总而言之,修复代码本身是不可能的 -
10) (恶搞)你似乎意识到自己学得还不够,学期快结束了,所以你试着做功课,产生了一些损坏/难以辨认的代码, panic ,无法修复然后你意识到有 StackOverflow。坏小狗,没有骨头。
11) 修复最明显错误后的代码[注意由于 main() 为空,代码没有效果]
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class DormAndMealPlanCalc extends JFrame {
private JPanel dormPanel;
private JPanel selectedDormPanel;
private JComboBox<String> DormBox;
private JLabel label;
private JTextField selectedDorm;
private String[] dorm = { "Allen Hall: $1,500 per semester", "Pike Hall: $1,100 per"
+ "semester", "Fathering Hall: 1,200 per semester", "Universty Suites: $1,800" };
protected class ComboBoxWindow1 extends JFrame {
protected ComboBoxWindow1() {
super( "Dorm plan" );
setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
setLayout( new BorderLayout() );
buildDormPanel();
buildSelectedDormPanel();
add( dormPanel, BorderLayout.CENTER );
add( selectedDormPanel, BorderLayout.SOUTH );
pack();
setVisible( true );
}
}
private void buildDormPanel() {
dormPanel = new JPanel();
DormBox = new JComboBox<>( dorm );
DormBox.addActionListener( new ComboBoxListener() );
dormPanel.add( DormBox );
}
private void buildSelectedDormPanel() {
selectedDormPanel = new JPanel();
label = new JLabel( "You selected: " );
selectedDorm = new JTextField( 10 );
selectedDorm.setEditable( false );
selectedDormPanel.add( label );
selectedDormPanel.add( selectedDorm );
}
private class ComboBoxListener implements ActionListener {
@Override
public void actionPerformed( ActionEvent e ) {
String selection = (String) DormBox.getSelectedItem();
selectedDorm.setText( selection );
}
}
private JPanel mealPanel;
private JPanel selectedMealPanel;
private JComboBox<String> mealBox;
private JLabel label1;
private JTextField selectedMeal;
private JButton calcbutton;
private String[] meal = { "7 meals per week: $560 per semester",
"14 meals per week: $1,095 per semester",
"Unlimited meals: $1,500 per semester"
};
protected class ComboBoxWindow2 extends JFrame {
protected ComboBoxWindow2() {
super( "Meal plan" );
setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
setLayout( new BorderLayout() );
buildMealPanel();
buildSelectedMealPanel();
add( mealPanel, BorderLayout.CENTER );
add( selectedMealPanel, BorderLayout.SOUTH );
pack();
setVisible( true );
}
}
private void buildMealPanel() {
mealPanel = new JPanel();
mealBox = new JComboBox<>( meal );
mealBox.addActionListener( new ComboBoxListener() );
mealPanel.add( mealBox );
calcbutton = new JButton( "Calculate" );
calcbutton.addActionListener( new ActionListener() {
@Override
public void actionPerformed( ActionEvent e ) {
throw new UnsupportedOperationException( "Not supported yet." );
}
} );
}
private void buildSelectedMealPanel() {
selectedMealPanel = new JPanel();
label = new JLabel( "You selected: " );
selectedMeal = new JTextField( 10 );
selectedMeal.setEditable( false );
selectedMealPanel.add( label );
selectedMealPanel.add( selectedDorm );
}
private class ComboBoxListener1 implements ActionListener {
@Override
public void actionPerformed( ActionEvent e ) {
String selection = (String) DormBox.getSelectedItem();
selectedDorm.setText( selection );
JOptionPane.showMessageDialog( null, "Total is" + dorm + meal );
}
}
static public void main( String[] args ) {
// do your thing
}
}
TL;DR - 请先学习,再编码。
关于java - 更多关于组合框,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/10474836/