Java实现简易计算器

1、Java实训作业 题目： Java实现简易计算器 学 院： 姓 名： 学 号： 班 级： 20 年 月一、 实验目的通过课程设计，主要要达到两个目的，一是检验和巩固专业知识、二是提高综合素质和能力。此次课程设计实训主要是Java语言程序设计的实现。通过该课程设计，可以将课堂上掌握的理论知识与处理数据的业务相结合，以检验自己掌握知识的宽度、深度及对知识的综合运用能力。二、 实验要求用Java编写一个简单的计算器，使其能够实现最基本的功能，如简单的加、减、乘、除；平方根，倒数，平方等功能。三、 详细内容1. 界面设计界面设计使用GUI，其中有用到swing组件的TextField和Button，用

2、到awt中的BorderLayout和GridLayout布局管理方式，其图形界面如图1-1所示：图1-1其中主要代码为：public mainWindow()this.setTitle("计算器");/用户图形界面标题this.setVisible(true);/用户图形界面可缩小this.setResizable(false);/用户图形界面不可放大this.setSize(350,300);/设置用户图形界面的大小this.setLocation(400,150);/用户图形界面在屏幕中的显示位置JPanel panel1 = new JPanel();/新建一个画板

3、JPanel panel2 = new JPanel();button1 = new JButton("1");.reset = new JButton("CE");Container container = this.getContentPane();container.add(panel2,BorderLayout.NORTH);container.add(panel1);panel1.setLayout(new GridLayout(5,4);/将画板1分为4行5列result.setEnabled(false);result.setFont(ne

4、w Font("Dialog",Font.BOLD,25);/运算结果的字体大小result.setEditable(false);result.setHorizontalAlignment(SwingConstants.RIGHT);panel1.add(reciprocal);/分别将20个按钮依次添加到画板panel1中，并设置各自的大小reciprocal.setFont(new Font("Dialog",Font.PLAIN,20);.panel1.add(divide);divide.setFont(new Font("Dialo

5、g",Font.PLAIN,20);panel2.setLayout(new GridLayout();panel2.add(result);/画板panel2添加运算结果2. 四则运算较为简单的实现了简单的加、减、乘、除运算，主要代码如下：ActionListener equal1 = new ActionListener()/实现四则运算public void actionPerformed(ActionEvent e)String str = result.getText();b = DatatypeConverter.parseDouble(str);if(flag = &q

6、uot;+")c = a + b;else if(flag = "-")c = a - b;else if(flag = "*")c = a * b;else if(flag = "/" | b != 0)c = a / b;if(flag != "=")result.setText("" + c);elseresult.setText("零不能做除数！");a = 0;b = 0;c = 0;flag = ""3. 其他功能另外添加了平方根，倒

7、数，平方等功能，主要代码如下：平方根运算的实现：ActionListener sqrt1= new ActionListener()public void actionPerformed(ActionEvent e)String str = result.getText();double i = DatatypeConverter.parseDouble(str);i = Math.sqrt(i);result.setText("" + i);倒数运算的实现：ActionListener reciprocal1 = new ActionListener()public vo

8、id actionPerformed(ActionEvent e)String str = result.getText();double i = DatatypeConverter.parseDouble(str);i = 1/i;result.setText("" + i);平方运算的实现：ActionListener square1 = new ActionListener()public void actionPerformed(ActionEvent e)String str = result.getText();double i = DatatypeConver

9、ter.parseDouble(str);i = i*i;result.setText("" + i);4. 程序测试经测试发现本计算器基本功能均能实现，可正常运行计算，针对功能实现的代码部分过于简单，可以对其进行改善提高，方便用户使用！5. 实训小结通过对计算器窗体的编写，熟悉了java图形用户界面的设计原理和程序结构，熟悉了java中awt和swing的组合。学会将书本上的知识运用在实际中，提升了编程能力。四、 源代码import java.awt.BorderLayout;import java.awt.Color;import java.awt.Container;

10、import java.awt.Font;import java.awt.GridLayout;importent.ActionEvent;import java.awt.event.ActionListener;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JPanel;import javax.swing.JTextField;import javax.swing.SwingConstants;import javax.xml.bind.DatatypeConverter;public cla

11、ss Calculatorpublic static void main(String args)new mainWindow();/新建主类调用class mainWindow extends JFrameJTextField result = new JTextField("0");/结果栏用于存储运算结果JButton button0;/按钮0JButton button1;/按钮1JButton button2;/按钮2JButton button3;/按钮3JButton button4;/按钮4JButton button5;/按钮5JButton button

12、6;/按钮6JButton button7;/按钮7JButton button8;/按钮8JButton button9;/按钮9JButton reciprocal;/倒数按钮JButton square;/平方按钮JButton sqrt;/平方根按钮JButton reset;/清零按钮JButton add;/加法按钮JButton reduce;/减法按钮JButton multiply;/乘法按钮JButton divide;/除法按钮JButton equal;/等号按钮JButton point;/小数点按钮double a,b,c;String flag;public ma

13、inWindow()this.setTitle("计算器");/用户图形界面标题this.setVisible(true);/用户图形界面可缩小this.setResizable(false);/用户图形界面不可放大this.setSize(350,300);/设置用户图形界面的大小this.setLocation(400,150);/用户图形界面在屏幕中的显示位置JPanel panel1 = new JPanel();/新建一个画板JPanel panel2 = new JPanel();button1 = new JButton("1");butt

14、on2 = new JButton("2");button3 = new JButton("3");button4 = new JButton("4");button5 = new JButton("5");button6 = new JButton("6");button7 = new JButton("7");button8 = new JButton("8");button9 = new JButton("9");button0

15、= new JButton("0");reciprocal = new JButton("1/X");square = new JButton("X2");sqrt = new JButton("");add = new JButton("+");reduce = new JButton("-");multiply = new JButton("*");divide = new JButton("/");equal = new JBut

16、ton("=");point = new JButton(".");reset = new JButton("CE");Container container = this.getContentPane();container.add(panel2,BorderLayout.NORTH);container.add(panel1);panel1.setLayout(new GridLayout(5,4);/将画板1分为4行5列result.setEnabled(false);result.setFont(new Font("

17、Dialog",Font.BOLD,25);/运算结果的字体大小result.setEditable(false);result.setHorizontalAlignment(SwingConstants.RIGHT);panel1.add(reciprocal);/分别将20个按钮依次添加到画板panel1中，并设置各自的大小reciprocal.setFont(new Font("Dialog",Font.PLAIN,20);panel1.add(square);square.setFont(new Font("Dialog",Font.P

18、LAIN,20);panel1.add(sqrt);sqrt.setFont(new Font("Dialog",Font.PLAIN,20);panel1.add(reset);reset.setFont(new Font("Dialog",Font.PLAIN,20);panel1.add(button7);button1.setFont(new Font("Dialog",Font.PLAIN,20);panel1.add(button8);button2.setFont(new Font("Dialog",

19、Font.PLAIN,20);panel1.add(button9);button3.setFont(new Font("Dialog",Font.PLAIN,20);panel1.add(add);add.setFont(new Font("Dialog",Font.PLAIN,20);panel1.add(button4);button4.setFont(new Font("Dialog",Font.PLAIN,20);panel1.add(button5);button5.setFont(new Font("Dialo

20、g",Font.PLAIN,20);panel1.add(button6);button6.setFont(new Font("Dialog",Font.PLAIN,20);panel1.add(reduce);reduce.setFont(new Font("Dialog",Font.PLAIN,25);panel1.add(button1);button7.setFont(new Font("Dialog",Font.PLAIN,20);panel1.add(button2);button8.setFont(new Fo

21、nt("Dialog",Font.PLAIN,20);panel1.add(button3);button9.setFont(new Font("Dialog",Font.PLAIN,20);panel1.add(multiply);multiply.setFont(new Font("Dialog",Font.PLAIN,20);panel1.add(button0);button0.setFont(new Font("Dialog",Font.PLAIN,20);panel1.add(point);point.

22、setFont(new Font("Dialog",Font.PLAIN,20);panel1.add(equal);equal.setFont(new Font("Dialog",Font.PLAIN,25);equal.setForeground(Color.red);/将等号设置为红色panel1.add(divide);divide.setFont(new Font("Dialog",Font.PLAIN,20);panel2.setLayout(new GridLayout();panel2.add(result);/画板p

23、anel2添加运算结果button0.addActionListener(al0);/设置20个按钮的监听事件button1.addActionListener(al1);button2.addActionListener(al2);button3.addActionListener(al3);button4.addActionListener(al4);button5.addActionListener(al5);button6.addActionListener(al6);button7.addActionListener(al7);button8.addActionListener(al

24、8);button9.addActionListener(al9);reciprocal.addActionListener(reciprocal1);square.addActionListener(square1);sqrt.addActionListener(sqrt1);reset.addActionListener(reset1);add.addActionListener(add1);point.addActionListener(point1);multiply.addActionListener(multiply1);divide.addActionListener(divid

25、e1);equal.addActionListener(equal1);reduce.addActionListener(reduce1);ActionListener al0 = new ActionListener()/各个按钮的监听事件实现运算public void actionPerformed(ActionEvent e)String str = result.getText();result.setText(str + "0");ActionListener al1 = new ActionListener()public void actionPerforme

26、d(ActionEvent e)String str = result.getText();result.setText(str + "1");ActionListener al2 = new ActionListener()public void actionPerformed(ActionEvent e)String str = result.getText();result.setText(str + "2");ActionListener al3 = new ActionListener()public void actionPerformed(

27、ActionEvent e)String str = result.getText();result.setText(str + "3");ActionListener al4 = new ActionListener()public void actionPerformed(ActionEvent e)String str = result.getText();result.setText(str + "4");ActionListener al5 = new ActionListener()public void actionPerformed(Ac

28、tionEvent e)String str = result.getText();result.setText(str + "5");ActionListener al6 = new ActionListener()public void actionPerformed(ActionEvent e)String str = result.getText();result.setText(str + "6");ActionListener al7 = new ActionListener()public void actionPerformed(Acti

29、onEvent e)String str = result.getText();result.setText(str + "7");ActionListener al8 = new ActionListener()public void actionPerformed(ActionEvent e)String str = result.getText();result.setText(str + "8");ActionListener al9 = new ActionListener()public void actionPerformed(Action

30、Event e)String str = result.getText();result.setText(str + "9");ActionListener sqrt1= new ActionListener()public void actionPerformed(ActionEvent e)String str = result.getText();double i = DatatypeConverter.parseDouble(str);i = Math.sqrt(i);result.setText("" + i);ActionListener r

31、eciprocal1 = new ActionListener()public void actionPerformed(ActionEvent e)String str = result.getText();double i = DatatypeConverter.parseDouble(str);i = 1/i;result.setText("" + i);ActionListener square1 = new ActionListener()public void actionPerformed(ActionEvent e)String str = result.g

32、etText();double i = DatatypeConverter.parseDouble(str);i = i*i;result.setText("" + i);ActionListener multiply1 = new ActionListener()public void actionPerformed(ActionEvent e)String str = result.getText();a = DatatypeConverter.parseDouble(str);flag = "*"result.setText("");ActionListener divide1 = new ActionListener()public void actionPerformed(ActionEvent e)String str = result.getText();a = DatatypeConverter.parseDouble(str);flag = "/"result.setText("");ActionListener add1 = new ActionListen