counter.java

我是初学者

import java.awt.*;
import javax.swing.*;
import java.awt.event.ActionListener;
import java.util.EventListener;
import java.awt.event.ActionEvent;

public class Counter extends JFrame implements ActionListener 
{
	JLabel lb1,lb2,lb3,lb4,lb5,lb6;
	JTextField tf=new JTextField("");
	JButton bt1[]=new JButton[10];
	JButton clear,equl;
	JButton jia,jian,cheng,chu;
	String s;
	float i=0,result=0;
	boolean flag=true;

	
	JPanel jp1,jp2,jp3,jp4,jp5,jp6;
	public Counter()
	{
		super("迷你计算器");
		Container con=this.getContentPane();
		con.setLayout(new BorderLayout());
		
		lb1=new JLabel("         计算结果：");
		lb2=new JLabel("     ");
		lb3=new JLabel("      ");
		lb4=new JLabel("      ");
		lb5=new JLabel("      ");
		lb6=new JLabel("    ");
		tf=new JTextField("0");
	
		for(int i=0;i<10;i++)
		{
			bt1[i]=new JButton(""+i);
			
			
		}
		clear=new JButton("归零");
		equl=new JButton("=");
		jia=new JButton("+");
		jian=new JButton("-");
		cheng=new JButton("*");
		chu=new JButton("/");
		
		
		jp1=new JPanel();
		jp1.setLayout(new GridLayout(1,2));
		jp2=new JPanel();
		jp2.setLayout(new GridLayout(4,3));
		jp3=new JPanel();
		jp3.setLayout(new BorderLayout());
		jp4=new JPanel();
		jp4.setLayout(new GridLayout(4,1));
		jp5=new JPanel();
		jp5.setLayout(new BorderLayout());
		jp6=new JPanel();
		jp6.setLayout(new BorderLayout());
		
		
		con.add("North",jp1);
		jp1.add(lb1);
		jp1.add(tf);
		con.add("Center",jp5);
		jp5.add("Center",jp3);
		jp5.add("East",lb3);
		jp5.add("West",lb4);
		jp5.add("South",lb5);
		jp3.add("North",lb2);
		
		jp3.add("West",jp6);
		jp6.add("East",lb6);
		jp6.add("West",jp2);
		for(int i=0;i<10;i++)
		{
			jp2.add(bt1[i]);
			bt1[i].addActionListener(this);
		}
		
		jp2.add(clear);
		clear.addActionListener(this);
		jp2.add(equl);
		equl.addActionListener(this);
		jp3.add("East",jp4);
		jp4.add(jia);
		jia.addActionListener(this);
		jp4.add(jian);
		jian.addActionListener(this);
		jp4.add(cheng);
		cheng.addActionListener(this);
		jp4.add(chu);
		chu.addActionListener(this);
		
	
		
		
		this.setSize(300,300);
		this.setVisible(true);
	}
	public static void main(String args[])
	{
		new Counter();
		
	}

	public void actionPerformed(ActionEvent e) 
	{
		// TODO: Add your code here
		for(int j=0;j<10;j++)
		{
			if(e.getSource()==bt1[j])
				{
					if(i==0)
						tf.setText(""+j);
					else
					{
						tf.setText(tf.getText()+j);
					}
					i=Float.parseFloat(tf.getText());
				}
		}
		
	
		
		if(e.getSource()==clear)
			{
				tf.setText("0");
				result=0;
				i=Float.parseFloat(tf.getText());
				}	
		if(e.getSource()==equl)
			{
				if(s=="+") result=result+i;
				
				if(s=="-") result=result-i;
					
				if(s=="*") result=result*i;
				if(s=="/"&&i!=0) result=result/i;
					else if(s!="+"&&s!="-"&&s!="*")
							flag=false;
				if(flag==false)
						{
							tf.setText("除数不能为