问题
I am having a lot of issues with this application. I have been at this all day and cannot get this figured out. I have a Java application that is for a class. The issue that I am having is trying to get the JRadioButtons assigned to variables in the array then passing them into the formula. If someone could help I would appreciate it a lot.
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.text.NumberFormat;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.JRadioButton;
public class MortgageCalculatorGUI8 extends JFrame {
JPanel panel1 = new JPanel();
double Principal;
double [] Interest = {5.35, 5.5, 5.75};
double temp_Interest;
int [] Length = {7, 15, 30};
int temp_Length;
boolean ok = false;
public MortgageCalculatorGUI8(){
getContentPane ().setLayout (null);
setSize (400,400);
panel1.setLayout (null);
panel1.setBounds (0, 0, 2000, 800);
add (panel1);
JLabel mortgageLabel = new JLabel("Mortgage Amount $", JLabel.LEFT);
mortgageLabel.setBounds (15, 15, 150, 30);
panel1.add (mortgageLabel);
final JTextField mortgageText = new JTextField(10);
mortgageText.setBounds (130, 15, 150, 30);
panel1.add (mortgageText);
JLabel termLabel = new JLabel("Mortgage Term (Years)", JLabel.LEFT);
termLabel.setBounds (340, 40, 150, 30);
panel1.add (termLabel);
JTextField termText = new JTextField(3);
termText.setBounds (340, 70, 150, 30);
panel1.add (termText);
JLabel intRateLabel = new JLabel("Interest Rate (%)", JLabel.LEFT);
intRateLabel.setBounds (340, 94, 150, 30);
panel1.add (intRateLabel);
JTextField intRateText = new JTextField(5);
intRateText.setBounds (340, 120, 150, 30);
panel1.add (intRateText);
JLabel mPaymentLabel = new JLabel("Monthly Payment $", JLabel.LEFT);
mPaymentLabel.setBounds (550, 40, 150, 30);
panel1.add (mPaymentLabel);
JTextField mPaymentText = new JTextField(10);
mPaymentText.setBounds (550, 70, 150, 30);
panel1.add (mPaymentText);
// JLabel paymentLabel = new JLabel ("Payment #");
// JLabel balLabel = new JLabel (" Balance");
// JLabel ytdPrincLabel = new JLabel (" Principal");
// JLabel ytdIntLabel = new JLabel (" Interest");
JTextArea textArea = new JTextArea(10, 31);
textArea.setBounds (550, 100, 150, 30);
panel1.add (textArea);
JScrollPane scroll = new JScrollPane(textArea, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
scroll.setBounds (450, 200, 300, 150);
panel1.add (scroll);
public void rbuttons(){
JLabel tYears = new JLabel("Years of Loan Amount");
tYears.setBounds (30, 35, 150, 30);
panel1.add (tYears);
JRadioButton b7Yr = new JRadioButton("7 Years",false);
b7Yr.setBounds (30, 58, 150, 30);
panel1.add (b7Yr);
JRadioButton b15Yr = new JRadioButton("15 Years",false);
b15Yr.setBounds (30, 80, 150, 30);
panel1.add (b15Yr);
JRadioButton b30Yr = new JRadioButton("30 Years",false);
b30Yr.setBounds (30, 101, 150, 30);
panel1.add (b30Yr);
JLabel tInterest = new JLabel("Interest Rate Of the Loan");
tInterest.setBounds (175, 35, 150, 30);
panel1.add(tInterest);
JRadioButton b535Int = new JRadioButton("5.35% Interest",false);
b535Int.setBounds (178, 58, 150, 30);
panel1.add (b535Int);
JRadioButton b55Int = new JRadioButton("5.5% Interest",false);
b55Int.setBounds (178, 80, 150, 30);
panel1.add (b55Int);
JRadioButton b575Int = new JRadioButton("5.75% Interest",false);
b575Int.setBounds (178, 101, 150, 30);
panel1.add (b575Int);
}
JButton calculateButton = new JButton("CALCULATE");
calculateButton.setBounds (30, 400, 120, 30);
panel1.add (calculateButton);
calculateButton.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e)
{
if(e.getSource () == b7Yr){
b7Yr = Length[0];
}
if(e.getSource () == b15Yr){
b15Yr = Length[1];
}
if(e.getSource () == b30Yr){
b30Yr = Length[2];
}
if(e.getSource () == b535Int){
b535Int = Interest[0];
}
if(e.getSource () == b55Int){
b55Int = Interest[1];
}
if(e.getSource () == b575Int){
b575Int = Interest[2];
}
double Principal;
// double [] Interest;
// int [] Length;
double M_Interest = Interest /(12*100);
double Months = Length * 12;
Principal = Double.parseDouble (mortgageText.getText());
double M_Payment = Principal * ( M_Interest / (1 - (Math.pow((1 + M_Interest), - Months))));
NumberFormat Money = NumberFormat.getCurrencyInstance();
}
});
JButton clearButton = new JButton("CLEAR");
clearButton.setBounds (160, 400, 120, 30);
panel1.add (clearButton);
clearButton.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e)
{
mortgageText.setText (null);
b7Yr.setSelected (false);
b15Yr.setSelected (false);
b30Yr.setSelected (false);
b535Int.setSelected (false);
b55Int.setSelected (false);
b575Int.setSelected (false);
}
});
JButton exitButton = new JButton("EXIT");
exitButton.setBounds (290, 400, 120, 30);
panel1.add (exitButton);
exitButton.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e)
{
System.exit(0);
}
});
}
public static void main(String[] args) {
MortgageCalculatorGUI8 frame = new MortgageCalculatorGUI8();
frame.setBounds (400, 200, 800, 800);
frame.setTitle ("Mortgage Calculator 1.0.4");
frame.setDefaultCloseOperation (EXIT_ON_CLOSE);
frame.setVisible (true);
}
}
回答1:
Shoot, I'll show you in an example of what I meant in my last comment:
Myself, I'd create an array of JRadioButtons as a class field for each group that I used as well as a ButtonGroup object for each cluster of JRadioButtons. Then in my calculate JButton's ActionListener, I'd get the selected radiobutton by either looping through the radio button array or from the ButtonGroups getSelection method (note though that this returns a ButtonModel object or null if nothing is selected).
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class InfoFromRadioBtns extends JPanel {
private static final long serialVersionUID = 1L;
private int[] foobars = {1, 2, 5, 10, 20};
private JRadioButton[] foobarRButtons = new JRadioButton[foobars.length];
private ButtonGroup foobarBtnGroup = new ButtonGroup();
public InfoFromRadioBtns() {
// jpanel to hold one set of radio buttons
JPanel radioBtnPanel = new JPanel(new GridLayout(0, 1));
radioBtnPanel.setBorder(BorderFactory
.createTitledBorder("Choose a Foobar"));
// iterate through the radio button array creating buttons
// and adding them to the radioBtnPanel and the
// foobarBtnGroup ButtonGroup
for (int i = 0; i < foobarRButtons.length; i++) {
// string for radiobutton to dislay -- just the number
String buttonText = String.valueOf(foobars[i]);
JRadioButton radiobtn = new JRadioButton("foobar " + buttonText);
radiobtn.setActionCommand(buttonText); // one way to find out which
// button is selected
radioBtnPanel.add(radiobtn); // add radiobutton to its panel
foobarBtnGroup.add(radiobtn); // add radiobutton to its button group
// add to array
foobarRButtons[i] = radiobtn;
}
// one way to get the selected JRadioButton
JButton getRadioChoice1 = new JButton("Get Radio Choice 1");
getRadioChoice1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
ButtonModel seletedModel = foobarBtnGroup.getSelection();
if (seletedModel != null) {
String actionCommand = seletedModel.getActionCommand();
System.out.println("selected foobar: " + actionCommand);
} else {
System.out.println("No foobar selected");
}
}
});
// another way to get the selected JRadioButton
JButton getRadioChoice2 = new JButton("Get Radio Choice 2");
getRadioChoice2.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String actionCommand = "";
for (JRadioButton foobarRButton : foobarRButtons) {
if (foobarRButton.isSelected()) {
actionCommand = foobarRButton.getActionCommand();
}
}
if (actionCommand.isEmpty()) {
System.out.println("No foobar selected");
} else {
System.out.println("selected foobar: " + actionCommand);
}
}
});
JPanel jBtnPanel = new JPanel();
jBtnPanel.add(getRadioChoice1);
jBtnPanel.add(getRadioChoice2);
// make main GUI use a BordeLayout
setLayout(new BorderLayout());
add(radioBtnPanel, BorderLayout.CENTER);
add(jBtnPanel, BorderLayout.PAGE_END);
}
private static void createAndShowUI() {
JFrame frame = new JFrame("InfoFromRadioBtns");
frame.getContentPane().add(new InfoFromRadioBtns());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
createAndShowUI();
}
});
}
}
Whatever you do, don't try to copy and paste any of this code into your program, because it simply isn't going to work that way (on purpose). It was posted only to illustrate the concepts that I've discussed above.
回答2:
I would extend JRadioButton to create a class capable of holding the variables you want. You can do this as an inner class to keep things simple.
private double pctinterest;
private int numyears; // within scope of your containing class
private class RadioButtonWithYears extends JRadioButton {
final private int years;
private int getYears() { return years; }
public RadioButtonWithYears(int years) {
super(years + " years",false);
this.years = years;
addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
numyears = getYears();
}
});
}
}
// elsewhere
RadioButtonWithYears b7Yr = new RadioButtonWithYears(7);
RadioButtonWithYears b15Yr = new RadioButtonWithYears(15);
RadioButtonWithYears b30Yr = new RadioButtonWithYears(30);
// then later
double M_Interest = java.lang.Math.pow((pctinternet / 100)+1, numyears);
Update: It isn't too far gone to salvage. I have incorporated the ButtonGroup as per Eels suggestion, and made the GUI part of it work (although you'll have to fix the layout) and marked where you need to sort out the calculation.
package stack.swing;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.math.BigDecimal;
import java.text.NumberFormat;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.JRadioButton;
public class MortgageCalculatorGUI8 extends JFrame {
JPanel panel1 = new JPanel();
Integer Principal;
boolean ok = false;
private BigDecimal temp_Interest;
private int temp_Length; // within scope of your containing class
private class JRadioButtonWithYears extends JRadioButton {
final private int years;
private int getYears() { return years; }
public JRadioButtonWithYears(int years) {
super(years + " years",false);
this.years = years;
addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
temp_Length = getYears();
}
});
}
}
private class JRadioButtonWithPct extends JRadioButton {
final private BigDecimal pct;
private BigDecimal getPct() { return pct; }
public JRadioButtonWithPct(String pct) {
super(pct + "%",false);
this.pct = new BigDecimal(pct);
addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
temp_Interest = getPct();
}
});
}
}
public MortgageCalculatorGUI8() {
getContentPane ().setLayout (null);
setSize (400,400);
panel1.setLayout (null);
panel1.setBounds (0, 0, 2000, 800);
add (panel1);
JLabel mortgageLabel = new JLabel("Mortgage Amount $", JLabel.LEFT);
mortgageLabel.setBounds (15, 15, 150, 30);
panel1.add (mortgageLabel);
final JTextField mortgageText = new JTextField(10);
mortgageText.setBounds (130, 15, 150, 30);
panel1.add (mortgageText);
JLabel termLabel = new JLabel("Mortgage Term (Years)", JLabel.LEFT);
termLabel.setBounds (340, 40, 150, 30);
panel1.add (termLabel);
JTextField termText = new JTextField(3);
termText.setBounds (340, 70, 150, 30);
panel1.add (termText);
JLabel intRateLabel = new JLabel("Interest Rate (%)", JLabel.LEFT);
intRateLabel.setBounds (340, 94, 150, 30);
panel1.add (intRateLabel);
JTextField intRateText = new JTextField(5);
intRateText.setBounds (340, 120, 150, 30);
panel1.add (intRateText);
JLabel mPaymentLabel = new JLabel("Monthly Payment $", JLabel.LEFT);
mPaymentLabel.setBounds (550, 40, 150, 30);
panel1.add (mPaymentLabel);
JTextField mPaymentText = new JTextField(10);
mPaymentText.setBounds (550, 70, 150, 30);
panel1.add (mPaymentText);
// JLabel paymentLabel = new JLabel ("Payment #");
// JLabel balLabel = new JLabel (" Balance");
// JLabel ytdPrincLabel = new JLabel (" Principal");
// JLabel ytdIntLabel = new JLabel (" Interest");
JTextArea textArea = new JTextArea(10, 31);
textArea.setBounds (550, 100, 150, 30);
panel1.add (textArea);
JScrollPane scroll = new JScrollPane(textArea, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
scroll.setBounds (450, 200, 300, 150);
panel1.add (scroll);
// jpanel to hold one set of radio buttons
JPanel yearsPanel = new JPanel(new GridLayout(0, 1));
yearsPanel.setBorder(BorderFactory
.createTitledBorder("Years of Loan Amount"));
yearsPanel.setBounds(30, 55, 150, 150);
panel1.add (yearsPanel);
final ButtonGroup yearsGroup = new ButtonGroup();
int years[] = { 7, 15, 30 };
for (int i = 0; i < years.length; i++) {
JRadioButtonWithYears radiobtn = new JRadioButtonWithYears(years[i]);
yearsPanel.add(radiobtn); // add radiobutton to its panel
yearsGroup.add(radiobtn); // add radiobutton to its button group
}
// jpanel to hold one set of radio buttons
JPanel pctPanel = new JPanel(new GridLayout(0, 1));
pctPanel.setBorder(BorderFactory
.createTitledBorder("Interest Rate Of the Loan"));
pctPanel.setBounds(175, 55, 180, 150);
panel1.add (pctPanel);
final ButtonGroup pctGroup = new ButtonGroup();
String pct[] = { "5.35", "5.5", "5.75" };
for (int i = 0; i < pct.length; i++) {
JRadioButtonWithPct radiobtn = new JRadioButtonWithPct(pct[i]);
pctPanel.add(radiobtn); // add radiobutton to its panel
pctGroup.add(radiobtn); // add radiobutton to its button group
}
final JButton calculateButton = new JButton("CALCULATE");
calculateButton.setBounds (30, 400, 120, 30);
panel1.add (calculateButton);
calculateButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
double M_Interest = temp_Interest.doubleValue() /(12*100);
double Months = temp_Length * 12;
Principal = Integer.parseInt(mortgageText.getText());
double M_Payment = Principal * ( M_Interest / (1 - (Math.pow((1 + M_Interest), - Months))));
NumberFormat Money = NumberFormat.getCurrencyInstance();
/** MORE STUFF TO HAPPEN HERE */
}
});
JButton clearButton = new JButton("CLEAR");
clearButton.setBounds (160, 400, 120, 30);
panel1.add (clearButton);
clearButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
mortgageText.setText (null);
yearsGroup.clearSelection();
pctGroup.clearSelection();
}
});
JButton exitButton = new JButton("EXIT");
exitButton.setBounds (290, 400, 120, 30);
panel1.add (exitButton);
exitButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
});
}
public static void main(String[] args) {
MortgageCalculatorGUI8 frame = new MortgageCalculatorGUI8();
frame.setBounds (400, 200, 800, 800);
frame.setTitle ("Mortgage Calculator 1.0.4");
frame.setDefaultCloseOperation (EXIT_ON_CLOSE);
frame.setVisible (true);
}
}
来源：https://stackoverflow.com/questions/6727933/plmortgage-calculator-gui-issue-with-a-lot