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

S.N.

構造函數與說明

1

PopupMenu()
Creates a new popup menu with an empty name.

2

PopupMenu(String label)
Creates a new popup menu with the specified name.

類方法

S.N.

方法和說明

1

void addNotify()
Creates the popup menu's peer.

2

AccessibleContext getAccessibleContext()
Gets the AccessibleContext associated with this PopupMenu.

3

MenuContainer getParent()
Returns the parent container for this menu component.

4

void show(Component origin, int x, int y)
Shows the popup menu at the x, y position relative to an origin component.

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程序 D:/ > AWT > com > yiibai > gui >

AWTMenuDemo

package com.yiibai.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 comyiibaiguiAWTMenuDemo.java

如果沒有錯誤出現，這意味着編譯成功。使用下面的命令來運行程序。

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

驗證下面的輸出。（點擊屏幕中間。）