第二周：java事件处理

import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class A extends Applet implements ActionListener
{
Label lb;
TextField in,out;
public void init()
{
lb=new Label("请输入您的名字");
in=new TextField(6);
out=new TextField(20);
add(lb);
add(in);
add(out);
in.addActionListener(this);
}
public void actionPerformed(ActionEvent e)
{
out.setText(in.getText()+"欢迎光临！");
}
}

import java.awt.*;
import java.awt.event.*;
import java.applet.*;
public class ButtonDemo extends Applet implements ActionListener
{
String msg="";
public void init()
{
Button yes=new Button("是");
Button no=new Button("否");
Button maybe=new Button("取消");
add(yes);
add(no);
add(maybe);
yes.addActionListener(this);
no.addActionListener(this);
maybe.addActionListener(this);

}
public void actionPerformed(ActionEvent e)
{
String str=e.getActionCommand();
if(str=="是")
{
msg="您单击了按钮'是'.";
}
else if(str=="否")
{
msg="您单击了按钮'否'.";
}
else
{
msg="您单击了按钮'取消'.";
}
repaint();
}
public void paint(Graphics g)
{
g.drawString(msg, 6, 100);
}
}