我正在尝试将方法从一个类链接到一个主要的Tax Calculator程序。 我正在使用我的方法的Tax类。那个
我做错了所以主程序无法从Tax类调用方法吗？ 我觉得这与我的命令有关。
主要的预制代码：
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.NumberFormat;
import javax.swing.BorderFactory;
import javax.swing.ButtonGroup;
import javax.swing.JApplet;
import javax.swing.JButton;
import javax.swing.JFormattedTextField;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.border.EmptyBorder;
import HW5.Tax;
public class TaxCalculator extends JApplet{
private final JButton btnAmount= new JButton("<html>Tax<br/>Amount</html>");
private final JButton btnMarginal= new JButton("<html>Marginal<br/>Tax Rate</html>");
private final JButton btnAverage= new JButton("<html>Average<br/>Tax Rate</html>");
private final JButton btnTaxable= new JButton("<html>Taxable<br/>Income</html>");
private final JButton btnCalculate= new JButton("<html>Calculate<br/>Taxable Amount</html>");
private final JLabel lblOutput = new JLabel("Result");
private final JLabel lblDummy1 = new JLabel(" ");
private final JLabel lblDummy2 = new JLabel(" ");
private JFormattedTextField tfTaxable ;
private final JRadioButton radSingle = new JRadioButton("Single", true);
private final JRadioButton radMarried = new JRadioButton("Married");
private JFormattedTextField tfResult;
JPanel contentPanel = new JPanel(new BorderLayout());
JPanel mainPanel = new JPanel(new GridLayout(3,3,4,4));
JPanel buttonPanel = new JPanel(new GridLayout(1,4,3,4));
private NumberFormat amountFormat;
private final int SINGLE=1, MARRIED=2;
private int status=SINGLE;
public void init() {
initFormatter();
tfTaxable = new JFormattedTextField(amountFormat);
tfResult = new JFormattedTextField(amountFormat);
mainPanel.add(new JLabel("Taxable Income:"));
mainPanel.add(tfTaxable); mainPanel.add(lblDummy1);
mainPanel.add(new JLabel("Filing Status:"));
ButtonGroup bg = new ButtonGroup();
bg.add(radSingle);
bg.add(radMarried);
JPanel radioPanel = new JPanel(new GridLayout(1,2,3,4));
radioPanel.add(radSingle); radioPanel.add(radMarried);
mainPanel.add(radioPanel); mainPanel.add(lblDummy2);
mainPanel.add(lblOutput);
mainPanel.add(tfResult); tfResult.setEditable(false);
mainPanel.add(btnCalculate);
btnCalculate.setVisible(false);
btnCalculate.setEnabled(false);
contentPanel.add(mainPanel, BorderLayout.NORTH);
buttonPanel.add(btnAmount);
buttonPanel.add(btnMarginal);
buttonPanel.add(btnAverage);
buttonPanel.add(btnTaxable);
contentPanel.add(buttonPanel, BorderLayout.SOUTH);
contentPanel.setBorder(new EmptyBorder(10, 10, 10, 10) );
contentPanel.setBorder(
BorderFactory.createTitledBorder(BorderFactory.createLineBorder(Color.black),"2012 Tax Year"));
this.add(contentPanel);
this.setVisible(true);
btnAmount.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
toggleUI(false);
lblOutput.setText("Tax amount: ");
double income = ((Number)tfTaxable.getValue()).doubleValue();
double tax = Tax.getTaxAmount(income, status);
tfResult.setValue(new Double(tax));
}
});
btnMarginal.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
toggleUI(false);
lblOutput.setText("Marginal Tax Rate (%): ");
double income = ((Number)tfTaxable.getValue()).doubleValue();
double marginalRate = 100*Tax.getMarginalRate(income, status);
tfResult.setValue(new Double(marginalRate));
}
});
btnAverage.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
toggleUI(false);
lblOutput.setText("Average Tax Rate (%): ");
double income = ((Number)tfTaxable.getValue()).doubleValue();
double averageRate = 100*Tax.getAverageRate(income, status);
tfResult.setValue(new Double(averageRate));
/*tfResult.setText(
String.format("%,.2f", //change the following method
100*Tax.getTaxAmount(getInput(tfTaxable),status) ));*/
}
});
btnTaxable.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
lblOutput.setText("After tax amount: ");
toggleUI(true);
tfResult.requestFocus();
tfTaxable.setText("");
}
});
btnCalculate.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
double postTax = ((Number)tfResult.getValue()).doubleValue();
double preTax = Tax.getPreTaxAmount(postTax, status);
tfTaxable.setValue(new Double(preTax));
}
});
radSingle.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
TaxCalculator.this.status=TaxCalculator.this.SINGLE;
}
});
radMarried.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
TaxCalculator.this.status=TaxCalculator.this.MARRIED;
}
});
}
private void toggleUI(boolean getPreTax) {
tfResult.setEditable(getPreTax);
btnCalculate.setEnabled(getPreTax);
btnCalculate.setVisible(getPreTax);
}
private void initFormatter() {
amountFormat = NumberFormat.getNumberInstance();
//percentFormat = NumberFormat.getNumberInstance();
amountFormat.setMinimumFractionDigits(2);
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
JFrame.setDefaultLookAndFeelDecorated(true);
JFrame frame = new JFrame("Tax Calculator");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
TaxCalculator applet = new TaxCalculator();
frame.setContentPane(applet);//.getContentPane().add(applet, BorderLayout.CENTER);
applet.init();
applet.start();
//frame.setSize(700, 500);
frame.pack();
Dimension d = Toolkit.getDefaultToolkit().getScreenSize();
frame.setLocation((d.width - frame.getSize().width) / 2,
(d.height - frame.getSize().height) / 2);
frame.setVisible(true);
}
});
}
}
我在单独的Tax calss中使用的方法是：
getTaxAmount：
public static double getTaxAmount(double income, int status){
if (status == 1){
if (income < 8700) return 8700 * .10;
if (income < 35350) return 8700 * .10 + (income - 8700) * .15;
if (income < 85650) return 8700 * .10 + (35350 - 8700) * .15 + (income - 35350) * .25;
if (income < 178650) return 8700 * .10 + (35350 - 8700) * .15 + (85650 - 35350) * .25 + (income - 85650) * .28;
if (income < 335000)
return 8700 *.10 + (35350 - 8700) * .15 + (75000 - 35350) * .25 + (115000 - 85650) * .28 + (income - 178650) * .33;
else
return income * .35;
}
else{}
return income;
getAverageRate
public static double getAverageRate(double income, int status){
double averageRate;
if(status == 1){
if (income < 8700)
return ((income * .10) / income);
if (income < 35350)
return ((8700 * .10 + (income - 8700) * .15) / income);
if (income < 75000)
return ((8700 * .10 + (35350 - 8700) * .15 + (income - 35350) * .20) / income);
if (income < 115000)
return ((8700 * .10 + (35350 - 8700) * .15 + (75000 - 35350) * .20 + (income - 75000) * .25) / income);
if (income < 335000)
return ((8700 *.10 + (35350 - 8700) * .15 + (75000 - 35350) * .20 + (115000 - 75000) * .25 + (income - 115000) * .30) / income);
else{}
return averageRate;
}
return averageRate;
}
答案 0 :(得分：1)
如果您的方法与main方法位于单独的类文件中，那么原因是因为static只是本地范围。从方法签名中取出静态，你应该没问题。或者，如果将方法移动到与main方法相同的类文件中，请保留静态修饰符，它应该仍然有效。