AWT PopupMenu類

彈出菜單表示可以在一個組件內的指定位置動態彈出的菜單。

類的聲明

以下是java.awt.PopupMenu描述類的聲明：

public class CheckboxMenuItem
   extends MenuItem
      implements ItemSelectable, Accessible

類的構造函數

類方法

繼承的方法

這個類繼承的方法從以下類：

• java.awt.MenuItem

• java.awt.MenuComponent

• java.lang.Object

PopupMenu 實例

選擇使用任何編輯器創建以下java程式 D:/ > AWT > com > zaixian > gui >

package com.zaixian.gui;

import java.awt.*;
import java.awt.event.*;

public class AWTMenuDemo {
   private Frame mainFrame;
   private Label headerLabel;
   private Label statusLabel;
   private Panel controlPanel;

   public AWTMenuDemo(){
      prepareGUI();
   }

   public static void main(String[] args){
      AWTMenuDemo  awtMenuDemo = new AWTMenuDemo();
      awtMenuDemo.showPopupMenuDemo();
   }

   private void prepareGUI(){
      mainFrame = new Frame("Java AWT Examples");
      mainFrame.setSize(400,400);
      mainFrame.setLayout(new GridLayout(3, 1));
      mainFrame.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent windowEvent){
            System.exit(0);
         }
      });
      headerLabel = new Label();
      headerLabel.setAlignment(Label.CENTER);
      statusLabel = new Label();
      statusLabel.setAlignment(Label.CENTER);
      statusLabel.setSize(350,100);

      controlPanel = new Panel();
      controlPanel.setLayout(new FlowLayout());

      mainFrame.add(headerLabel);
      mainFrame.add(controlPanel);
      mainFrame.add(statusLabel);
      mainFrame.setVisible(true);
   }

   private void showPopupMenuDemo(){
      final PopupMenu editMenu = new PopupMenu("Edit");

      MenuItem cutMenuItem = new MenuItem("Cut");
      cutMenuItem.setActionCommand("Cut");

      MenuItem copyMenuItem = new MenuItem("Copy");
      copyMenuItem.setActionCommand("Copy");

      MenuItem pasteMenuItem = new MenuItem("Paste");
      pasteMenuItem.setActionCommand("Paste");

      MenuItemListener menuItemListener = new MenuItemListener();

      cutMenuItem.addActionListener(menuItemListener);
      copyMenuItem.addActionListener(menuItemListener);
      pasteMenuItem.addActionListener(menuItemListener);

      editMenu.add(cutMenuItem);
      editMenu.add(copyMenuItem);
      editMenu.add(pasteMenuItem);

      controlPanel.addMouseListener(new MouseAdapter() {
         public void mouseClicked(MouseEvent e) {
               editMenu.show(controlPanel, e.getX(), e.getY());
         }
      });
      controlPanel.add(editMenu);

      mainFrame.setVisible(true);
   }

   class MenuItemListener implements ActionListener {
      public void actionPerformed(ActionEvent e) {
         statusLabel.setText(e.getActionCommand()
            + " MenuItem clicked.");
      }
   }
}

編譯程序，使用命令提示符。進入到D:/> AWT，然後鍵入以下命令。

D:AWT>javac comzaixianguiAWTMenuDemo.java

如果沒有錯誤出現，這意味著編譯成功。使用下麵的命令來運行程式。

D:AWT>java com.zaixian.gui.AWTMenuDemo

驗證下麵的輸出。（點擊螢幕中間。）