j2se界面布局

最近一段时间在看j2se界面布局和事件的控制，如界面上处理List右键事件

 

MouseListener  -- 鼠标监听器

ActionListener   -- 所有监听器的父类

ItemListener     -- 用于捕获带有item的组件产生的事件

 

代码示例：

 

import java.awt.*;import java.awt.event.*;import java.applet.Applet;public class ListDemo extends Applet implements MouseListener, ActionListener,ItemListener {private TextArea output;private List mainList, fileList;private String newline;private PopupMenu popMenu = new PopupMenu();public void init() {newline = System.getProperty("line.separator");//mainList = new List(); //mainList.add("系统信息");mainList.add("交易成员");mainList.add("处理失败消息");mainList.add("下载文件列表");mainList.addActionListener(this);mainList.addItemListener(this);mainList.addMouseListener(this);String itemText[] = { "开始", "停止" };for (int i = 0; i < itemText.length; i++) {MenuItem item = new MenuItem(itemText[i]);item.addActionListener(this);popMenu.add(item);}//fileList = new List();fileList.add("http://127.0.0.1/test/test.txt");fileList.addActionListener(this);fileList.addItemListener(this);//GridBagLayout gridBag = new GridBagLayout();setLayout(gridBag);//GridBagConstraints lc = new GridBagConstraints();lc.fill = GridBagConstraints.BOTH;lc.weightx = 1.0;lc.weighty = 1.0;lc.gridheight = 2;gridBag.setConstraints(mainList, lc);add(mainList);gridBag.setConstraints(fileList, lc);add(fileList);output = new TextArea(10, 100);output.setEditable(false);GridBagConstraints tc = new GridBagConstraints();tc.fill = GridBagConstraints.BOTH;tc.gridx = 0;tc.gridy = 2;tc.weightx = 1.0;tc.weighty = 1.0;tc.gridwidth = GridBagConstraints.REMAINDER; // end rowgridBag.setConstraints(output, tc);add(output);add(popMenu);}public void actionPerformed(ActionEvent e) {List list = (List) (e.getSource());String language = (list == mainList) ? "主菜单" : "文件列表";output.append("Action event occurred on /"" + list.getSelectedItem()+ "/" in " + language + "." + newline);}public void itemStateChanged(ItemEvent e) {List list = (List) (e.getItemSelectable());String language = (list == mainList) ? "主菜单" : "文件列表";int index = ((Integer) (e.getItem())).intValue();if (e.getStateChange() == ItemEvent.SELECTED) {output.append("selected Index = " + index + " (/""+ list.getItem(index) + "/") in " + language + "."+ newline);} else { // the item was deselectedoutput.append("deselected Index = #" + index + " (/""+ list.getItem(index) + "/") in " + language + "."+ newline);}}public void mouseClicked(MouseEvent e) {// TODO Auto-generated method stub}public void mouseEntered(MouseEvent e) {// TODO Auto-generated method stub}public void mouseExited(MouseEvent e) {// TODO Auto-generated method stub}public void mousePressed(MouseEvent e) {// TODO Auto-generated method stub}public void mouseReleased(MouseEvent e) {// TODO Auto-generated method stubif (e.isPopupTrigger()) {System.out.println("e.getComponent()" + this + "e.getX() "+ e.getX() + "e.getY() " + e.getY());popMenu.show(e.getComponent(), e.getX(), e.getY());}}}