Java实现简易计算器

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(new 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(Dialog,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 = +)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 void 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 = DatatypeConverter.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;import java.awt.Font;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.JTextField;import javax.swing.SwingConstants;import javax.xml.bind.DatatypeConverter;public class 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 button6;/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 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JPanel panel2 = new JPanel();button1 = new JButton(1);button2 = 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 = 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 JButton(=);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(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.PLAIN,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,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(Dialog,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 Font(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.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panel2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(al8);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(divide1);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 actionPerformed(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(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(ActionEvent 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(ActionEvent 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(ActionEvent 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 reciprocal1 = 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.getText();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 = /;res