Intermediate Java(31) - Listening for User Events

import java.net.*;

import java.util.*;

import java.awt.*;

import java.applet.*;

import javax.swing.*;

import javax.swing.event.*;

public class Website extends JApplet {

private HashMap<String,URL> websiteInfo;

private ArrayList<String> titles;

private JList mainList;

//init

public void init(){

websiteInfo = new HashMap<String,URL>();

titles = new ArrayList<String>();

grabHTMLInfo();

add(new JLabel("What website do you want to visit?"),BorderLayout.NORTH);

mainList = new JList(titles.toArray());

mainList.addListSelectionListener(

new ListSelectionListener(){

public void valueChanged(ListSelectionEvent event){

Object object = mainList.getSelectedValue();

URL newDocument = websiteInfo.get(object);

AppletContext browser = getAppletContext();

browser.showDocument(newDocument);

}

}

);

add(new JScrollPane(mainList),BorderLayout.CENTER); → 放置mainList在JScrollPane

}

}

含義:

mainList.addListSelectionListener( → 如果選擇JList的內容

new ListSelectionListener(){

public void valueChanged(ListSelectionEvent event){

Object object = mainList.getSelectedValue(); 等於你在列表選擇值

URL newDocument = websiteInfo.get(object); 用存儲URL

AppletContext browser = getAppletContext(); 使用瀏覽器打開

browser.showDocument(newDocument); 進入該網址

}

}

);

}