如何用JAVA语言编写计算器小程序？

具体代码如下：

import javax.swing.*

import java.awt.event.*

import java.awt.*

public class Calculator  extends JFrame implements ActionListener  {

private JFrame jf

private JButton[] allButtons

private JButton clearButton

private JTextField jtf

public Calculator() {

//对图形组件实例化

jf=new JFrame("任静的计算器1.0：JAVA版")

jf.addWindowListener(new WindowAdapter(){

public void windowClosing(){

System.exit(0)

}

})

allButtons=new JButton[16]

clearButton=new JButton("清除")

jtf=new JTextField(25)

jtf.setEditable(false)

String str="123+456-789*0.=/"

for(int i=0i<allButtons.lengthi++){

allButtons[i]=new JButton(str.substring(i,i+1))

}

}

public void init(){

//完成布局

jf.setLayout(new BorderLayout())

JPanel northPanel=new JPanel()

JPanel centerPanel=new JPanel()

JPanel southPanel=new JPanel()

northPanel.setLayout(new FlowLayout())

centerPanel.setLayout(new GridLayout(4,4))

southPanel.setLayout(new FlowLayout())

northPanel.add(jtf)

for(int i=0i<16i++){

centerPanel.add(allButtons[i])

}

southPanel.add(clearButton)

jf.add(northPanel,BorderLayout.NORTH)

jf.add(centerPanel,BorderLayout.CENTER)

jf.add(southPanel,BorderLayout.SOUTH)

addEventHandler()

}

//添加事件监听

public void addEventHandler(){

jtf.addActionListener(this)

for(int i=0i<allButtons.lengthi++){

allButtons[i].addActionListener(this)

}

clearButton.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e) {

// TODO Auto-generated method stub

Calculator.this.jtf.setText("")

}

})

}

//事件处理

public void actionPerformed(ActionEvent e) {

//在这里完成事件处理  使计算器可以运行

String action=e.getActionCommand()

if(action=="+"||action=="-"||action=="*"||action=="/"){

}

}

public void setFontAndColor(){

Font f=new Font("宋体",Font.BOLD,24)

jtf.setFont(f)

jtf.setBackground(new Color(0x8f,0xa0,0xfb))

for(int i=0i<16i++){

allButtons[i].setFont(f)

allButtons[i].setForeground(Color.RED)

}

}

public void showMe(){

init()

setFontAndColor()

jf.pack()

jf.setVisible(true)

jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE)

}

public static void main(String[] args){

new Calculator().showMe()

}

}

class Ball {

public void play() {

System.out.println("玩球儿...")

}

}

class Football extends Ball {

public void play() {

System.out.println("使用足球运动")

}

}

class Basketball extends Ball {

public void play() {

System.out.println("使用篮球运动")

}

}

public class TestMain {

public static void main(String[] args) {

TestMain tm = new TestMain()

tm.testPlay()

}

public void testPlay() {

Ball ball = new Football()

ball.play()

ball = new Basketball()

ball.play()

}

}

/*

D:\>javac TestMain.java

D:\>java TestMain

使用足球运动

使用篮球运动

*/

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