example4_17.java

书中的例题

 /* 演示菜单程序 */
 import java.awt.*;
 import java.awt.event.*;
 public class  Example4_17 extends Frame implements ActionListener
 {  private MenuItem fileNew = new MenuItem("New");
    private MenuItem fileOpen = new MenuItem("Open");
    private MenuItem fileExit = new MenuItem("Exit");
    private MenuItem editCut = new MenuItem("Cut");
    private MenuItem editCopy = new MenuItem("Copy");
    private MenuItem editPaste = new MenuItem("Paste");
    public  Example4_17()
 	 {  super("Menu Test Program");
        Menu file = new Menu("File");
        file.add(fileNew); fileNew.setEnabled(false);
	    file.add(fileOpen); fileOpen.setEnabled(false);
	    file.addSeparator();
	    file.add(fileExit);  fileExit.setEnabled(true);
	    Menu edit = new Menu("Edit");
	    edit.add(editCut);   editCut.setEnabled(false);
        edit.add(editCopy);  editCopy.setEnabled(false);
        edit.add(editPaste); editPaste.setEnabled(false);
	    MenuBar bar = new MenuBar();
        bar.add(file);
	    bar.add(edit); 
	    setMenuBar(bar);
	    fileExit.addActionListener(this);
	    setSize(100,100);
	    show();
     }
    public void actionPerformed(ActionEvent e)
	 {  if(e.getSource() == fileExit)
	       System.exit(0);
     }
    public static void main(String args[])
	 { Example4_17 f = new  Example4_17();}
  }