Java - 简易记事本

没有自己以前用Windows API写的好看了。。。

JDK Version : 1.7.0

Source Code :

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

/**
 * The Main Window
 * @author Neo Smith
 */
class PadFrame extends Frame
{
    private MenuBar mb;
    private Menu menuFile;
    private Menu menuEdit;
    private MenuItem[] miFile;
    private TextArea ta;
    
    final private Frame frame = this;
    
    /**
     * The inner class
     * Message Handle
     */
    class EventExit implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            System.exit(0);
        }
    }
    
    class SystemExit extends WindowAdapter
    {
        public void windowClosing(WindowEvent e)
        {
            System.exit(0);
        }
    }
    
    class EventMenuClose implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            ta.setText(null);
        }
    }
    
    class EventOpenFile implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            //Create the OpenFile Dialog
            FileDialog dlg = new FileDialog(frame,"Open Files",FileDialog.LOAD);
            dlg.show();
            
            String strPath;
            if((strPath = dlg.getDirectory()) != null)
            {
                //get the full path of the selected file
                strPath += dlg.getFile();
                
                //open the file
                try
                {
                    FileInputStream fis = new FileInputStream(strPath);
                    BufferedInputStream bis = new BufferedInputStream(fis);
                    byte[] buf = new byte[3000];
                    int len = bis.read(buf);
                    
                    ta.append(new String(buf,0,len));
                    bis.close();
                }
                catch(Exception ex)
                {
                    ex.printStackTrace();
                }
            }
        }
    }
    
    /**
     * Construction Method
     * Adding Menu and TextArea components
     * @param strTitle 
     */
    public PadFrame(String strTitle)
    {
        super(strTitle);
        this.setLocation(400,200);
        this.setSize(900, 630);
        
        //Create the Menu Bar
        mb = new MenuBar();
        menuFile = new Menu("File");
        menuEdit = new Menu("Edit");
        miFile = new MenuItem[]{new MenuItem("Open"),new MenuItem("Close"),new MenuItem("Exit")};
        this.setMenuBar(mb);
        mb.add(menuFile);
        mb.add(menuEdit);
        for(int i = 0 ; i < miFile.length ; ++i)
        {
            menuFile.add(miFile[i]);
        }
        
        //Add event handle
        setMenuEventHandle(new EventExit(),"File",2);
        setMenuEventHandle(new EventOpenFile(),"File",0);
        setMenuEventHandle(new EventMenuClose(),"File",1);
        this.addWindowListener(new SystemExit());
        
        //add the TextArea component
        ta = new TextArea(30,30);
        this.add(ta);
    }
    public void setMenuEventHandle(ActionListener al,String strMenu,int index)
    {
        if(strMenu == "File")
        {
            miFile[index].addActionListener(al);
        }
    }
    public int getMenuItemAmount(String strMenu)
    {
        if("File" == strMenu)
        {
            return miFile.length;
        }
        
        return -1;
    }
    public static void main(String[] args)
    {
        PadFrame f = new PadFrame("NotePad");
        f.show();
    }
}