我有一个程序,我根据选择的单选按钮计算 2 个变量中的 1 个。出于某种原因,isSelected() 没有返回 true 或 false。我将在下面发布我的代码:
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import java.text.DecimalFormat;
public class FutureValueFrame extends JFrame {
public FutureValueFrame() {
setTitle("Sample App");
setSize(400,400);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args) {
JFrame f = new FutureValueFrame();
//GUI and BUTTONS
JRadioButton monthlyRadioButton = new JRadioButton("Monthly Payment");
JRadioButton loanAmountButton = new JRadioButton("Loan Amount");
ButtonGroup selection = new ButtonGroup();
selection.add(monthlyRadioButton);
selection.add(loanAmountButton);
JFormattedTextField loanAmountField = new JFormattedTextField(new DecimalFormat("####.##"));
JFormattedTextField interestRateField = new JFormattedTextField(new DecimalFormat("####.##"));
JFormattedTextField yearField = new JFormattedTextField(new DecimalFormat("####.##"));
JFormattedTextField monthlyPaymentField = new JFormattedTextField(new DecimalFormat("####.##"));
JPanel menuPanel = new JPanel();
menuPanel.setLayout(new GridLayout(1,2));
//ACTION LISTENER FOR RADIO BUTTONS
monthlyRadioButton.addActionListener(new SelectionListener(monthlyRadioButton, loanAmountButton, loanAmountField, monthlyPaymentField));
loanAmountButton.addActionListener(new SelectionListener(monthlyRadioButton, loanAmountButton, loanAmountField, monthlyPaymentField));
JPanel topPanel = new JPanel();
topPanel.setLayout(new GridLayout(1,2));
topPanel.setBorder(BorderFactory.createLineBorder(Color.BLACK));
topPanel.add(monthlyRadioButton);
topPanel.add(loanAmountButton);
JPanel botPanel = new JPanel();
botPanel.setLayout(new GridLayout(4,2));
botPanel.add(new JLabel("Loan Amount:"));
botPanel.add(loanAmountField);
botPanel.add(new JLabel("Yearly Interest Rate:"));
botPanel.add(interestRateField);
botPanel.add(new JLabel("Number of Years:"));
botPanel.add(yearField);
botPanel.add(new JLabel("Monthly Payment:"));
botPanel.add(monthlyPaymentField);
JPanel container = new JPanel();
container.setLayout(new GridLayout(3,1));
container.add(topPanel);
container.add(botPanel);
container.add(menuPanel);
f.add(container);
JButton calculateButton = new JButton("Calculate");
if (monthlyRadioButton.isSelected()){
calculateButton.addActionListener(new CalculateMonthlyListener(loanAmountField, interestRateField, yearField, monthlyPaymentField));
}
if (loanAmountButton.isSelected()){
calculateButton.addActionListener(new CalculateLoanListener(loanAmountField, interestRateField, yearField, monthlyPaymentField));
}
JButton exitButton = new JButton("Exit");
exitButton.addActionListener(new ExitListener());
menuPanel.add(calculateButton);
menuPanel.add(exitButton);
f.setVisible(true);
f.setLocationRelativeTo(null);
}
class CalculateMonthlyListener implements ActionListener {
private JFormattedTextField loanAmountField;
private JFormattedTextField monthlyPaymentField;
private JFormattedTextField interestRateField;
private JFormattedTextField yearField;
private float result;
public CalculateMonthlyListener (JFormattedTextField loanAmountField, JFormattedTextField interestRateField, JFormattedTextField yearField, JFormattedTextField monthlyPaymentField)
{
this.interestRateField = interestRateField;
this.yearField = yearField;
this.loanAmountField = loanAmountField;
this.monthlyPaymentField = monthlyPaymentField;
}
public void actionPerformed(ActionEvent event){
monthlyPaymentField.setValue(new Double(12.22));
System.out.println("You selected monthly");
}
}
class CalculateLoanListener implements ActionListener {
private JFormattedTextField loanAmountField;
private JFormattedTextField monthlyPaymentField;
private JFormattedTextField interestRateField;
private JFormattedTextField yearField;
private float result;
public CalculateLoanListener (JFormattedTextField loanAmountField, JFormattedTextField interestRateField, JFormattedTextField yearField, JFormattedTextField monthlyPaymentField)
{
this.interestRateField = interestRateField;
this.yearField = yearField;
this.loanAmountField = loanAmountField;
this.monthlyPaymentField = monthlyPaymentField;
}
public void actionPerformed(ActionEvent event){
loanAmountField.setValue(new Double(12.22));
System.out.println("You selected loan");
}
}
class ExitListener implements ActionListener {
public void actionPerformed(ActionEvent event){
//f.dispose();
System.exit(0);
//System.out.println("You clicked exit");
}
}
class SelectionListener implements ActionListener {
private JRadioButton monthlyRadioButton;
private JRadioButton loanAmountButton;
private JFormattedTextField loanAmountField;
private JFormattedTextField monthlyPaymentField;
public SelectionListener (JRadioButton monthlyRadioButton, JRadioButton loanAmountButton, JFormattedTextField loanAmountField, JFormattedTextField monthlyPaymentField)
{
this.monthlyRadioButton = monthlyRadioButton;
this.loanAmountButton = loanAmountButton;
this.loanAmountField = loanAmountField;
this.monthlyPaymentField = monthlyPaymentField;
}
public void actionPerformed(ActionEvent event){
if(event.getSource() == monthlyRadioButton){
loanAmountField.setEditable(false);
monthlyPaymentField.setEditable(true);
}
else {
monthlyPaymentField.setEditable(false);
loanAmountField.setEditable(true);
}
}
}
}
我相信问题出现在这个片段中:
if (monthlyRadioButton.isSelected()){
calculateButton.addActionListener(new CalculateMonthlyListener(loanAmountField, interestRateField, yearField, monthlyPaymentField));
}
if (loanAmountButton.isSelected()){
calculateButton.addActionListener(new CalculateLoanListener(loanAmountField, interestRateField, yearField, monthlyPaymentField));
}
isSelected 没有返回 true。我尝试创建一个 int i 并将其设置为 1。我在每个条件下检查了 i==1 并且它们正确执行。
有什么见解吗?