ji.java

计算器的JAVA源码是针对学习软件工程专业的学生在进行《软件工程导论》课时的必备参考工具

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ji extends JFrame implements ActionListener
{ 
   private    String name[] = {"1","2","3","4","5","6","7","8","9","0",".","=","+","-","*","/","  Clear","BackSpace"};
   String     s="";
   int        flag=0; 
   double     x;
   private    JButton button[] = new JButton[name.length];
   JTextField window = new JTextField(16);
   public ji() 
   { 
     super("Java简易计算器");
     setSize(200,300); 
     Container c = getContentPane(); 
     c.setLayout(new GridLayout(2,2)); 
     JPanel result = new JPanel();
     result.add(window); 
     for(int i= 0;i<name.length;i++) 
     { 
        button[i] = new JButton(name[i]); 
        result.add(button[i]);
     } 
     c.add(result); 
     for(int i= 0;i<name.length;i++) 
     { 
        button[i].addActionListener(this); 
     } 
     show(); 
   }
   public void actionPerformed(ActionEvent e) 
   { 
     if (e.getSource()==button[12]) 
        { 
          x=Double.parseDouble(s); 
          flag=1; 
	  window.setText("");
	  s=""; 
	}
	else if (e.getSource()==button[13]) 
	        { 
 		  x=Double.parseDouble(s); 
		  flag=2; 
		  window.setText(""); 
		  s=""; 
		}
		else if (e.getSource()==button[14]) 
			{ 
			  x=Double.parseDouble(s); 
			  flag=3; 
			  window.setText(""); 
			  s=""; 
			} 
 			else if (e.getSource()==button[15]) 
				{
				  x=Double.parseDouble(s); 
				  flag=4; 
				  window.setText(""); 
				  s=""; 
				}
				else if (e.getSource()==button[11]) 
					{ 
					  switch(flag) 
					  { 
						case 1: 
						     { 
 							x=x+Double.parseDouble(s); 
							String s=String.valueOf(x); 
							window.setText(s); 
							break; 
						     } 
						case 2: 
						     { 
							x=x-Double.parseDouble(s); 
							String s=String.valueOf(x); 
							window.setText(s); 
							break; 
						     }
						case 3: 
						     { 
							x=x*Double.parseDouble(s); 
							String s=Double.toString(x); 
							window.setText(s);
							break; 
						     } 
						case 4: 
					  	     { 
                                                        if(Double.parseDouble(s)==0) 
							  {
							    window.setText("除数不能为0"); 
							    break; 
							  } 
							else
						        {
							  x=x/Double.parseDouble(s); 
							  String s=String.valueOf(x); 
							  window.setText(s); 
							}
							break; 
						     } 
					  } 
					} 
					else if(e.getSource()==button[16]) 
						{ 
						  StringBuffer str = new StringBuffer(window.getText()); 
						  int n=str.length();
						  int m=n-1; 
						  s = String.valueOf(str.delete(m,n)); 
						  window.setText(s); 
						}
				                else if(e.getSource()==button[17]) 
							{ 
							  window.setText(""); 
							  s=""; 
							  flag=0; 
							} 
							else 
							{ 
							  s=s+e.getActionCommand();
							  window.setText(s); 
							}
   } 
public static void main(String[] args)
{ 
ji bun = new ji(); 
bun.addWindowListener(new WindowAdapter() 
{ 
public void windowListener(WindowEvent e)
{System.exit(0); } }); }}