我不能输入两位数作为计算器。我也无法让明确的C运算符工作。我的点号似乎也没有用。下面的代码使用java swing创建一个计算器，并对单个数字进行加法，乘法，减法和除法。
//First the necessary packages are imported
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
/**@return a BODMAS calculator using Javax Swing and awt
* *@author Cihan Altunok
*@version 1
*/
//implementing ActionListener to listen to events. JFrame is also extended to add support to Swing components
public class Calculator extends JFrame implements ActionListener {
//declaring some variables to be used in our program
JFrame guiCalculatorFrame;
JPanel buttonPanel;
JTextArea numberCalculator;
int calculatorOpr=0;
int currentCalculation;
//EventQueue invokeLater is used to ensure the run method is called in the dispatch thread of the EventQueue
//declaring the constructor for the class
public Calculator()
{
//instantiating guiCalculatorFrame
guiCalculatorFrame=new JFrame();
//the red cross sign drawn to exit the window
guiCalculatorFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
guiCalculatorFrame.setTitle("Calculator");
//setting the size of the frame
guiCalculatorFrame.setSize(400,400);
//The setLocationRelativeTo has been set to null to center the window
guiCalculatorFrame.setLocationRelativeTo(null);
//JTextField is created to allow a set of characters to be entered
numberCalculator=new JTextArea();
//setting the alignment of JTextField along the RIGHT axis
numberCalculator.setAlignmentX(JTextField.RIGHT);
//making the textfield not editable
numberCalculator.setEditable(false);
//container containing the components in the north region
guiCalculatorFrame.add(numberCalculator, BorderLayout.NORTH);
//panel is created and we will add buttons to the panel later in the program
buttonPanel=new JPanel();
//setting Layout to GridLayout to lay the components in a rectangular grid
buttonPanel.setLayout(new GridLayout(5,5));
//adding the buttons to the frame. Putting the buttons in the center
guiCalculatorFrame.add(buttonPanel,BorderLayout.CENTER);
// a following for loop is done to add the numberButtons
for (int i=0;i<10;i++)
{
addNumberButton(buttonPanel,String.valueOf(i));
}
//next the five mathematical operators are added
addActionButton(buttonPanel,1,"+");
addActionButton(buttonPanel,2,"-");
addActionButton(buttonPanel,3,"*");
addActionButton(buttonPanel,4,"/");
addActionButton(buttonPanel,5,"^2");
addActionButton(buttonPanel,6,"C");
addActionButton(buttonPanel,7,"^");
addActionButton(buttonPanel,8,".");
//equalSign Button is created
JButton equalsSignButton=new JButton("=");
//the action command for the equal sign button is set
equalsSignButton.setActionCommand("=");
equalsSignButton.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent event)
//checking if the numberCalculator field is a valid mathematical operator
{
if (!numberCalculator.getText().isEmpty())
{
//turning text into integer
int number=Integer.parseInt(numberCalculator.getText());
// doing a series of if statements for the list of operations
if (calculatorOpr==1)
{
int calculate=currentCalculation+number;
numberCalculator.setText(Integer.toString(calculate));
}
else if (calculatorOpr==2)
{
int calculate=currentCalculation-number;
numberCalculator.setText(Integer.toString(calculate));
}
else if (calculatorOpr==3)
{
int calculate=currentCalculation*number;
numberCalculator.setText(Integer.toString(calculate));
}
else if (calculatorOpr==4)
{
int calculate=currentCalculation/number;
numberCalculator.setText(Integer.toString(calculate));
}
else if (calculatorOpr==5)
{
int calculate=currentCalculation*currentCalculation;
numberCalculator.setText(Integer.toString(calculate));
}
else if (calculatorOpr==6)
{
numberCalculator.setText("");
}
else if (calculatorOpr==7)
{
int calculate=(int) Math.sqrt(Integer.parseInt(numberCalculator.getText()));
numberCalculator.setText(Integer.toString(calculate));
}
else if (calculatorOpr==8)
{
numberCalculator.append(".");
}
}
}
});
//adding equals sign to the panel
buttonPanel.add(equalsSignButton);
//setting the visibility to True so the frame can be seen
guiCalculatorFrame.setVisible(true);
}
//passing two paremeters to the addNumberButton method
private void addNumberButton(Container contain, String name) {
JButton buttonOne=new JButton(name);
//setting the action command for the button created above
buttonOne.setActionCommand(name);
buttonOne.addActionListener(this);
//adding buttonOne to the container
contain.add(buttonOne);
}
//passing three parameters to the addActionButton method
private void addActionButton(Container contain, int i, String text) {
JButton buttonOne=new JButton(text);
//setting the action command for the button created above
buttonOne.setActionCommand(text);
//creating a new class
Operators addAction=new Operators(i);
buttonOne.addActionListener(addAction);
//adding buttonOne to the container
contain.add(buttonOne);
}
public void actionPerformed(ActionEvent event) {
//returning the command string associated with this string
String i=event.getActionCommand();
//setting the Text to the specified String
numberCalculator.setText(i);
}
//creating an inner class and implementing ActionListener
private class Operators implements ActionListener
{
private int operators;
//creating a constructor and passing a parameter
public Operators(int operation)
{
operators=operation;
}
public void actionPerformed(ActionEvent event)
{
currentCalculation=Integer.parseInt(numberCalculator.getText());
calculatorOpr=operators;
}
}
}*
答案 0 :(得分：1)
问题是你正在覆盖文本字段。并且C按钮的动作侦听器是错误的。这将解决您的基本问题，但仍有一些工作要做。例如，您目前没有处理.。
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JTextField;
public class Calculator extends JFrame implements ActionListener {
// declaring some variables to be used in our program
JFrame guiCalculatorFrame;
JPanel buttonPanel;
JTextArea numberCalculator;
int calculatorOpr = 0;
int currentCalculation;
boolean isOperatorActive = false;
// EventQueue invokeLater is used to ensure the run method is called in the
// dispatch thread of the EventQueue
// declaring the constructor for the class
public Calculator() {
// instantiating guiCalculatorFrame
guiCalculatorFrame = new JFrame();
// the red cross sign drawn to exit the window
guiCalculatorFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
guiCalculatorFrame.setTitle("Calculator");
// setting the size of the frame
guiCalculatorFrame.setSize(400, 400);
// The setLocationRelativeTo has been set to null to center the window
guiCalculatorFrame.setLocationRelativeTo(null);
// JTextField is created to allow a set of characters to be entered
numberCalculator = new JTextArea();
// setting the alignment of JTextField along the RIGHT axis
numberCalculator.setAlignmentX(JTextField.RIGHT);
// making the textfield not editable
numberCalculator.setEditable(false);
// container containing the components in the north region
guiCalculatorFrame.add(numberCalculator, BorderLayout.NORTH);
// panel is created and we will add buttons to the panel later in the
// program
buttonPanel = new JPanel();
// setting Layout to GridLayout to lay the components in a rectangular
// grid
buttonPanel.setLayout(new GridLayout(5, 5));
// adding the buttons to the frame. Putting the buttons in the center
guiCalculatorFrame.add(buttonPanel, BorderLayout.CENTER);
// a following for loop is done to add the numberButtons
for (int i = 0; i < 10; i++) {
addNumberButton(buttonPanel, String.valueOf(i));
}
// next the five mathematical operators are added
addActionButton(buttonPanel, 1, "+");
addActionButton(buttonPanel, 2, "-");
addActionButton(buttonPanel, 3, "*");
addActionButton(buttonPanel, 4, "/");
addActionButton(buttonPanel, 5, "^2");
addActionButton(buttonPanel, 6, "C");
addActionButton(buttonPanel, 7, "^");
addActionButton(buttonPanel, 8, ".");
// equalSign Button is created
JButton equalsSignButton = new JButton("=");
// the action command for the equal sign button is set
equalsSignButton.setActionCommand("=");
equalsSignButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent event) {
// checking if the numberCalculator field is a valid mathematical
// operator
isOperatorActive = true;
if (!numberCalculator.getText().isEmpty()) {
// turning text into integer
int number = Integer.parseInt(numberCalculator.getText());
// doing a series of if statements for the list of
// operations
int calculate = 0;
switch (calculatorOpr) {
case 1:
calculate = currentCalculation + number;
numberCalculator.setText(Integer.toString(calculate));
break;
case 2:
calculate = currentCalculation - number;
numberCalculator.setText(Integer.toString(calculate));
break;
case 3:
calculate = currentCalculation * number;
numberCalculator.setText(Integer.toString(calculate));
break;
case 4:
calculate = currentCalculation / number;
numberCalculator.setText(Integer.toString(calculate));
break;
case 5:
calculate = currentCalculation * currentCalculation;
numberCalculator.setText(Integer.toString(calculate));
break;
case 7:
calculate = (int) Math.sqrt(Integer
.parseInt(numberCalculator.getText()));
numberCalculator.setText(Integer.toString(calculate));
break;
case 8:
numberCalculator.append(".");
break;
default:
break;
}
}
}
});
// adding equals sign to the panel
buttonPanel.add(equalsSignButton);
// setting the visibility to True so the frame can be seen
guiCalculatorFrame.setVisible(true);
}
// passing two parameters to the addNumberButton method
private void addNumberButton(Container contain, String name) {
JButton buttonOne = new JButton(name);
// setting the action command for the button created above
buttonOne.setActionCommand(name);
buttonOne.addActionListener(this);
// adding buttonOne to the container
contain.add(buttonOne);
}
// passing three parameters to the addActionButton method
private void addActionButton(Container contain, int i, String text) {
JButton buttonOne = new JButton(text);
// setting the action command for the button created above
buttonOne.setActionCommand(text);
// creating a new class
Operators addAction = new Operators(i);
buttonOne.addActionListener(addAction);
// adding buttonOne to the container
contain.add(buttonOne);
}
public void actionPerformed(ActionEvent event) {
// returning the command string associated with this string
String i = event.getActionCommand();
// setting the Text to the specified String
if(isOperatorActive){
numberCalculator.setText(i);
isOperatorActive = false;
} else {
numberCalculator.setText(numberCalculator.getText() + i);
}
}
// creating an inner class and implementing ActionListener
private class Operators implements ActionListener {
private int operators;
// creating a constructor and passing a parameter
public Operators(int operation) {
operators = operation;
}
public void actionPerformed(ActionEvent event) {
isOperatorActive = true;
switch (operators) {
case 6:
numberCalculator.setText("");
currentCalculation = 0;
calculatorOpr = 0;
break;
case 8:
isOperatorActive = false;
default:
currentCalculation = Integer.parseInt(numberCalculator.getText());
calculatorOpr = operators;
break;
}
}
}
}
答案 1 :(得分：0)
import javax.swing.*;
import java.awt.*;
/*
@ Author 12CSE54
@ Date 29.10.14
*/
public class calculator1 extends JFrame
{
public calculator1() {
initComponents();
}
int a,b,c;
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
a=Integer.parseInt(jTextField1.getText());
b=Integer.parseInt(jTextField2.getText());
c=a+b;
jTextField3.setText(String.valueOf(c));
}
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
a=Integer.parseInt(jTextField1.getText());
b=Integer.parseInt(jTextField2.getText());
c=a-b;
jTextField3.setText(String.valueOf(c));
}
private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {
a=Integer.parseInt(jTextField1.getText());
b=Integer.parseInt(jTextField2.getText());
c=a*b;
jTextField3.setText(String.valueOf(c));
}
private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) {
a=Integer.parseInt(jTextField1.getText());
b=Integer.parseInt(jTextField2.getText());
c=a/b;
jTextField3.setText(String.valueOf(c));
}
private void jButton5ActionPerformed(java.awt.event.ActionEvent evt) {
jTextField1.setText("");
jTextField2.setText("");
jTextField3.setText("");
}
public static void main(String ar[])
{
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new calculator1().setVisible(true);
}
});
}