adder1.java

java实现的简单的整型的加法器

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.JOptionPane;
public class adder1 extends JPanel{

	private JLabel inputlabel1,inputlabel2,sumlabel,resultlabel;
    private JTextField a1,a2;
    private JButton sum;
    public adder1()
    {
    	inputlabel1=new JLabel("enter a number:");
    	inputlabel2=new JLabel("enter another number:");
    	sumlabel=new JLabel("the sum:");
    	resultlabel=new JLabel("---");
    	sum=new JButton("+");
    	sum.addActionListener(new ButtonListener());
    	a1=new JTextField(5);
    	
    	a2=new JTextField(5);
    	panelListener listener=new panelListener();
    	addMouseListener(listener);
    	add(inputlabel1);
    	add(a1);
    	add(inputlabel2);
    	add(a2);
    	add(sum);
    	add(sumlabel);
    	
    	add(resultlabel);
    	setPreferredSize(new Dimension (400,100));
    	setBackground(Color.white);
    	
	}
    private class ButtonListener implements ActionListener
    {
    	public void actionPerformed(ActionEvent event)
    	{
    		int s1,s2,r;
    		//int b=0;
    		//JOptionPane.showMessageDialog(null,"shuruchuwu");
    		String text1=a1.getText();
    		String text2=a2.getText();
    		if(text1.equals("")||text2.equals(""))
    			JOptionPane.showMessageDialog(null,"请输入正确的数字");
    		else{
    		
    		s1=Integer.parseInt(text1);
    		s2=Integer.parseInt(text2);
    		r=s1+s2;
    		resultlabel.setText(Integer.toString(r));
    		}
    		
    		
    	}
    }
    private class panelListener implements MouseListener
    {public void mousePressed(MouseEvent event){} 
    public void mouseEntered(MouseEvent event){}
    public void mouseReleased(MouseEvent event){}
    public void mouseExited(MouseEvent event){}
    
     public void mouseClicked(MouseEvent event)
     {
    	 JOptionPane.showMessageDialog(null,"请点击正确的位置");
     }
    }
}