java 计算器源代码.doc

package com.niit.calculator;import java.awt.BorderLayout;import java.awt.Color;import java.awt.GridBagLayout;import java.awt.GridLayout;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.event.ItemEvent;import java.awt.event.ItemListener;import java.awt.event.MouseEvent;import java.awt.event.MouseListener;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JOptionPane;import javax.swing.JPanel;import javax.swing.JTextField;public class Calculator extends JFrameString str1=;String str2=;String str3=;double result=0;double number=0;int count=0;private JPanel pnl1;private JPanel pnl2;private JPanel pnl3;private JPanel pnl4;/文本框private JTextField txt;/按钮private JButton btnBackspace;private JButton btnC;private JButton btnCe;private JButton btn;private String s;public Calculator()this.setLayout(new BorderLayout();this.setTitle(计算器);this.setBounds(100, 100, 350, 300);this.setResizable(false);this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);/初始化组件initcomponent(); /* * 初始化组件 */public void initcomponent()/初始化pnlpnl1=new JPanel();pnl2=new JPanel();pnl3=new JPanel();pnl4=new JPanel();/上面this.add(pnl1,BorderLayout.NORTH);txt=new JTextField();txt.setHorizontalAlignment(JLabel.RIGHT);txt.setColumns(30);pnl1.add(txt);/中间this.add(pnl2,BorderLayout.CENTER);pnl2.setLayout(new BorderLayout();pnl2.add(pnl3,BorderLayout.NORTH);btnBackspace=new JButton(Backspace);btnBackspace.setForeground(Color.red);btnC=new JButton(C);btnC.setForeground(Color.red);btnCe=new JButton(CE);btnCe.setForeground(Color.red);pnl3.add(btnBackspace);pnl3.add(btnC);pnl3.add(btnCe);/下面pnl2.add(pnl4,BorderLayout.CENTER);pnl4.setLayout(new GridLayout(4,6);btn=new JButton24;s=new StringMC,7,8,9,/,sqrt,MR,4,5,6,*,%,MS,1,2,3,-,1/x,M+,0,+/-,.,+,=;for(int i=0;i24;i+)btni=new JButton(si);pnl4.add(btni);/按钮绑定点击监听器btni.addActionListener(new btnListener();btnC.addActionListener(new btnListener();btnBackspace.addActionListener(new btnListener();for(int i=0;i1)count=1;JOptionPane.showMessageDialog(null, 只能有一个点);else/是数字的情况if(str.equals(0)|str.equals(1)|str.equals(2)|str.equals(3)|str.equals(4)|str.equals(5)|str.equals(6)|str.equals(7)|str.equals(8)|str.equals(9)|str.equals(.)/记录数字str1+=str;/将第一个数转化为double类型number=Double.parseDouble(str1);/显示在文本框中txt.setText(str1);catch(NumberFormatException e2)/运算符的情况if(str.equals(+)|str.equals(-)|str.equals(*)|str.equals(/)|str.equals(%)|str.equals(sqrt)|str.equals(1/x)|str.equals(=)|str.equals(+/-)if(!str1.equals()&str1.indexOf(.)=str1.length()-1)JOptionPane.showMessageDialog(null, 最后一位不能为.);elsestr1=;if(str3!=null)if(str2.equals(+)result+=number;else if(str2.equals(-)result-=number;else if(str2.equals(*)result*=number;else if(str2.equals(/)if(number=0)JOptionPane.showMessageDialog(null, 除数不能为0);elseresult=result/number;else if(str2.equals(%)result=result%number;/sqtr情况if(str.equals(sqrt)result=Math.sqrt(number);txt.setText(result+);number=result;if(str.equals(1/x)result=1/number;txt.setText(result+);number=result;if(str.equals(+/-)result=(-number);txt.setText(result+);number=result;str3=1;if(str.equals(=)txt.setText(result+);str3=;number=result;/保存numberresult=number;/保留运算符str2=str;count=0;/c的情况if(str.equals(C)str1=;txt.setText(0);/backspacetryif(str.equals(Backspace)str1=str1.substring(0,str1.length()-1);txt.setText(str1