一个最简单的计算器

Posted on 2006-10-12 10:09 my 阅读(343) 评论(0)  编辑  收藏 所属分类: java
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

class MyFrame extends JFrame implements ActionListener
{
        private JButton ButtonNum[]=new JButton[16];
        private String countCode[]={"/","*","-","+","=","."};
        
        private JTextField displayField=new JTextField();        
        private JPanel pan=new JPanel();
        
        private String displayStr="";
        private double firstNum=0,secondNum=0;
        private int countNum;
        private boolean start=false,end=false;
        
    public MyFrame()
    {    
        super("模拟简便计算器");
        setSize(400,400);
        Container c=getContentPane();
        c.setLayout(new BorderLayout());    
        
        displayField.setHorizontalAlignment(JTextField.RIGHT);
        displayField.setFont(new Font("TimesRoman",Font.BOLD,50));
        displayField.setBackground(Color.gray);
        displayField.setEditable(false);
        displayField.addActionListener(this);        
        c.add(displayField,"North");
        c.add(pan,"Center");
            
        pan.setLayout(new GridLayout(4,4));
        
        for(int n=0;n<16;n++)  //定义按键属性
        {    
            if(n<10)
            {
                ButtonNum[n]=new JButton(n+"");
                ButtonNum[n].setFont(new Font("TimesRoman",Font.BOLD,50));                
                ButtonNum[n].setBackground(Color.lightGray);
                ButtonNum[n].addActionListener(this);
                pan.add(ButtonNum[n]);
            }
            
            else
            {
                ButtonNum[n]=new JButton(countCode[15-n]);
                ButtonNum[n].setFont(new Font("TimesRoman",Font.BOLD,50));      
                ButtonNum[n].addActionListener(this);
                pan.add(ButtonNum[n]);
            }    
        }    
        setVisible(true);
    }
    
    public static void main(String args[])
    {    
        MyFrame myFrame=new MyFrame();
    }
        
    public void windowClosing(WindowEvent e)
    {
        dispose();
        System.exit(0);
    }
    
    public void actionPerformed(ActionEvent e)
    {
        for(int i=0;i<16;i++)
        {
            if(i<=10)   //算数按钮输入事件处理  判断并显示输入的运算数字
            {
                if(e.getSource()==ButtonNum[i] && start==false)
                {
                    displayStr=displayStr+ButtonNum[i].getLabel();
                    displayField.setText(displayStr);
                    
                }
                
                if(e.getSource()==ButtonNum[i] && start==true)
                {
                    displayStr=displayStr+ButtonNum[i].getLabel();
                    displayField.setText(displayStr);
                    end=true;        
                }            
            }
        
            if(i>=12 && i<=15)     //运算按钮事件处理  判断并接受输入的运算数字
            {    
                if(e.getSource()==ButtonNum[i] && start==false)
                {
                    firstNum=Double.valueOf(displayField.getText()).doubleValue();
                    countNum=i;
                    displayField.setText("");
                    displayStr="";
                    start=true;            
                }
                
                else
                {    if(e.getSource()==ButtonNum[i] )
                    {
                        countNum=0;
                        displayField.setText("");
                        displayStr="";
                        firstNum=0;
                        secondNum=0;
                        end=false;    
                    }                                                                        
                }                    
            }
        
            if(e.getSource()==ButtonNum[11])    //等号按钮事件处理
            {
                secondNum=Double.valueOf(displayField.getText()).doubleValue();
                        
                if(start=true && end==true)
                {                                                        
                    if(countNum==12)
                        displayField.setText(firstNum+secondNum+"");
                    if(countNum==13)
                        displayField.setText(firstNum-secondNum+"");
                    if(countNum==14)
                        displayField.setText(firstNum*secondNum+"");
                    if(countNum==15 && secondNum!=0)
                        displayField.setText(firstNum/secondNum+"");                                
                }
                            
                countNum=0;
                displayStr="";
                firstNum=0;
                secondNum=0;
                start=false;
                end=false;    
            }
        }            
    }
}

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