JAVA GUI MyEditor.java

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

public class MyEditor extends JFrame
{
JTextArea txt; //代表文字區域的物件
JFileChooser file = new JFileChooser(".");
public static void main(String[] args)
{
MyEditor f = new MyEditor();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(240,240);
f.setVisible(true);
}
public MyEditor()
{
txt = new JTextArea(80,80);
JScrollPane p = new JScrollPane(txt);
Container contentPane = getContentPane();
contentPane.add(buildMenu(),"North");
contentPane.add(p,"Center");
}
//建立功能表內容的方法
public JMenuBar buildMenu()
{
JMenuBar mbar= new JMenuBar(); //建立功能表欄
JMenu menu = new JMenu("檔案 (F)");
menu.setMnemonic(KeyEvent.VK_F);
mbar.add(menu);
//設定檔案功能表的項目
//開啟檔案
JMenuItem item = new JMenuItem("開啟(O)",KeyEvent.VK_O);
item.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
readfile();
}
});
menu.add(item); //將項目加到功能表中
//儲存檔案
item = new JMenuItem("儲存 (S)" , KeyEvent.VK_S);
item.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
writefile();
}
});
menu.add(item);
//結束程式
item = new JMenuItem("結束(X)",KeyEvent.VK_X);
item.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
System.exit(0);
}
});
menu.add(item); //將項目加到功能表中
return mbar;

}
public void readfile()
{
int state = file.showOpenDialog(this);
if(state == JFileChooser.APPROVE_OPTION)
{
File f = file.getSelectedFile();
try
{
//讀取檔案
txt.read(new FileReader(f),"");
}
catch(IOException e)
{
System.out.println(e);
}
setTitle(f.getName()); //將視窗標題設為檔案名稱
}
}
public void writefile()
{
int state =  file.showSaveDialog(this);
if(state == JFileChooser.APPROVE_OPTION)
{
File f = file.getSelectedFile();
//寫入檔案
try
{
txt.write(new FileWriter(f));

}
catch(IOException e)
{
System.out.println(e);
}

}
}
}