Calculator类：（包含算术方法）
package mycalcgie;
import java.util.*;
class Calculator {
public int TEMP, SolveTEMP;
public static void Add (int TEMP, int SolveTEMP){
SolveTEMP += TEMP;
}
public static void Subtract (int TEMP, int SolveTEMP){
SolveTEMP -= TEMP;
}
public static void Divide (int TEMP, int SolveTEMP){
SolveTEMP /= TEMP;
}
public static void Multiply (int TEMP, int SolveTEMP){
SolveTEMP *= TEMP;
}
}
WindowedCalculator类：（包含GUI）package mycalcgie;
import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
class WindowedCalculator extends Calculator{
JButton Num1;
JButton Num2;
JButton Num3;
JButton Num4;
JButton Num5;
JButton Num6;
JButton Num7;
JButton Num8;
JButton Num9;
JButton Num0;
JButton Equal;
JButton AddBt;
JButton Subtractbt;
JButton Multiplybt;
JButton Dividebt;
JButton Solvebt;
JButton Clearbt;
JTextField Result;
int TEMP;
int SolveTEMP;
Boolean addBool = false ;
Boolean subBool = false ;
Boolean divBool = false ;
Boolean mulBool = false ;
String display = "";
public WindowedCalculator() {
JPanel p1 = new JPanel();
p1.setLayout(new GridLayout(4, 3));
p1.add(Num1 = new JButton("1"));
p1.add(Num2 = new JButton("2"));
p1.add(Num3 = new JButton("3"));
p1.add(Num4 = new JButton("4"));
p1.add(Num5 = new JButton("5"));
p1.add(Num6 = new JButton("6"));
p1.add(Num7 = new JButton("7"));
p1.add(Num8 = new JButton("8"));
p1.add(Num9 = new JButton("9"));
p1.add(Num0 = new JButton("0"));
p1.add(Clearbt = new JButton("C"));
JPanel p2 = new JPanel();
p2.setLayout(new FlowLayout());
p2.add(Result = new JTextField(10));
Result.setHorizontalAlignment(JTextField.RIGHT);
Result.setEditable(true);
JPanel p3 = new JPanel();
p3.setLayout(new GridLayout(5, 1));
p3.add(AddBt = new JButton("+"));
p3.add(Subtractbt = new JButton("-"));
p3.add(Multiplybt = new JButton("*"));
p3.add(Dividebt = new JButton("/"));
p3.add(Solvebt = new JButton("="));
JPanel p = new JPanel();
p.setLayout(new GridLayout());
p.add(p2, BorderLayout.NORTH);
p.add(p1, BorderLayout.SOUTH);
p.add(p3, BorderLayout.EAST);
Num1.addActionListener(new ListenToOne());
Num2.addActionListener(new ListenToTwo());
Num3.addActionListener(new ListenToThree());
Num4.addActionListener(new ListenToFour());
Num5.addActionListener(new ListenToFive());
Num6.addActionListener(new ListenToSix());
Num7.addActionListener(new ListenToSeven());
Num8.addActionListener(new ListenToEight());
Num9.addActionListener(new ListenToNine());
Num0.addActionListener(new ListenToZero());
AddBt.addActionListener(new ListenToAdd());
Subtractbt.addActionListener(new ListenToSubtract());
Multiplybt.addActionListener(new ListenToMultiply());
Dividebt.addActionListener(new ListenToDivide());
Solvebt.addActionListener(new ListenToSolve());
Clearbt.addActionListener(new ListenToClear());
}
class ListenToClear implements ActionListener {
public void actionPerformed(ActionEvent e) {
//display = Result.getText();
Result.setText("");
addBool = false ;
subBool = false ;
mulBool = false ;
divBool = false ;
TEMP = 0;
SolveTEMP = 0;
}
}
class ListenToOne implements ActionListener {
public void actionPerformed(ActionEvent e) {
display = Result.getText();
Result.setText(display + "1");
}
}
class ListenToTwo implements ActionListener {
public void actionPerformed(ActionEvent e) {
display = Result.getText();
Result.setText(display + "2");
}
}
class ListenToThree implements ActionListener {
public void actionPerformed(ActionEvent e) {
display = Result.getText();
Result.setText(display + "3");
}
}
class ListenToFour implements ActionListener {
public void actionPerformed(ActionEvent e) {
display = Result.getText();
Result.setText(display + "4");
}
}
class ListenToFive implements ActionListener {
public void actionPerformed(ActionEvent e) {
display = Result.getText();
Result.setText(display + "5");
}
}
class ListenToSix implements ActionListener {
public void actionPerformed(ActionEvent e) {
display = Result.getText();
Result.setText(display + "6");
}
}
class ListenToSeven implements ActionListener {
public void actionPerformed(ActionEvent e) {
display = Result.getText();
Result.setText(display + "7");
}
}
class ListenToEight implements ActionListener {
public void actionPerformed(ActionEvent e) {
display = Result.getText();
Result.setText(display + "8");
}
}
class ListenToNine implements ActionListener {
public void actionPerformed(ActionEvent e) {
display = Result.getText();
Result.setText(display + "9");
}
}
class ListenToZero implements ActionListener {
public void actionPerformed(ActionEvent e) {
display = Result.getText();
Result.setText(display + "0");
}
}
class ListenToAdd implements ActionListener {
public void actionPerformed(ActionEvent e) {
TEMP = Integer.parseInt(Result.getText());
Result.setText("+");
addBool = true ;
}
}
class ListenToSubtract implements ActionListener {
public void actionPerformed(ActionEvent e) {
TEMP = Integer.parseInt(Result.getText());
Result.setText("-");
subBool =true;
}
}
class ListenToMultiply implements ActionListener {
public void actionPerformed(ActionEvent e) {
TEMP = Integer.parseInt(Result.getText());
Result.setText("*");
mulBool =true;
}
}
class ListenToDivide implements ActionListener {
public void actionPerformed(ActionEvent e) {
TEMP = Integer.parseInt(Result.getText());
Result.setText("/");
divBool =true;
}
}
class ListenToSolve implements ActionListener {
public void actionPerformed(ActionEvent e) {
SolveTEMP = Integer.parseInt( Result.getText() );
if ( addBool == true )
WindowedCalculator.Add (TEMP, SolveTEMP);
else if ( subBool == true )
WindowedCalculator.Subtract (TEMP, SolveTEMP);
else if ( mulBool == true )
WindowedCalculator.Multiply (TEMP, SolveTEMP);
else if ( divBool == true )
WindowedCalculator.Divide (TEMP, SolveTEMP);
Result.setText( Integer.toString( SolveTEMP ) );
addBool = false ;
subBool = false ;
mulBool = false ;
divBool = false ;
}
}
/*public static void main(String[] args) {
// TODO Auto-generated method stub
WindowedCalculator calc = new WindowedCalculator();
calc.pack();
calc.setLocationRelativeTo(null);
calc.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
calc.setVisible(true);
}*/
}
Tester类：（包含main方法）package mycalcgie;
import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
import java.util.*;
class Tester extends WindowedCalculator {
public static void main(String[] args) {
WindowedCalculator calc = new WindowedCalculator();
calc.pack();
calc.setLocationRelativeTo(null);
calc.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
calc.setVisible(true);
}
}
除Tester.java外，所有内容都可以编译。返回4找不到符号错误，提示
variable calc of the type WindowedCalculator。 最佳答案
没有类的实例，您将无法访问实例字段。
您可能希望将这些字段设为静态。
关于java - 在主类中找不到符号，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/17972503/