cal.java

用ＪＡＶＡ 编写的一个菜单程序 实现了一些基本计算和信息的录入

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
public class Cal extends JDialog implements ActionListener{
	
	JPanel p1=new JPanel();
	JPanel p2=new JPanel();
	
	JTextField a=new JTextField(15);
	JTextField b=new JTextField(15);
	JButton ok=new JButton("计算");
	
	public Cal(){
		setModal(true);
		setBackground(Color.blue);
		Container contentPane=this.getContentPane();
		contentPane.setLayout(new GridLayout(5,1));
		p1.add(new JLabel("请输入整数"));p1.add(a);p1.add(ok);
		p2.add(new JLabel("结果"));p2.add(b);
		
		ok.addActionListener(this);
		
		
		contentPane.add(p1);
		contentPane.add(p2);
		
		setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
		setSize(400,200);
		setTitle("求阶乘");
		setVisible(true);	
	}
	
	public void actionPerformed(ActionEvent e){
		
	 int x;
	 int result=1;
     
	 try{
	 	x=Integer.parseInt(a.getText());
	 	
	 	if(x==0)  result=1;
	 	else
	 	for(int i=1;i<=x;i++)
	 	result=result*i;
	 	b.setText(Integer.toString(result));
	 	
	 	
	 }catch(Exception ee){b.setText("不是整数");				
	}
	}	
	void creat(){
		JDialog.setDefaultLookAndFeelDecorated(true);
       	Font font=new Font("JFrame",Font.PLAIN,14);
        Enumeration keys=UIManager.getLookAndFeelDefaults().keys();
        while(keys.hasMoreElements()){
        	Object key=keys.nextElement();
        	if(UIManager.get(key) instanceof Font)UIManager.put(key,font);	     
        }
        
       }
	 	
	}