example10_9.java

不错的教程 适合中高级人员的使用

import java.awt.*;import java.io.*;
import java.awt.event.*;
public class Example10_9
{  public static void main(String args[])
    {  FileWindows win=new FileWindows();
    }
}
class  FileWindows extends Frame implements ActionListener
{   FileDialog filedialog_save,filedialog_load;//声明2个文件对话筐
    MenuBar menubar;
    Menu menu;
    MenuItem itemOpen,itemSave;
    TextArea text;
    BufferedReader in;  
    FileReader file_reader;
    BufferedWriter out; 
    FileWriter tofile;
    FileWindows()
    {  super("带文件对话框的窗口");     
       setSize(260,270);               
       setVisible(true);    
       menubar=new MenuBar();   
       menu=new Menu("文件"); 
       itemOpen=new MenuItem("打开文件");
       itemSave=new MenuItem("保存文件"); 
       itemOpen.addActionListener(this); 
       itemSave.addActionListener(this);
       menu.add(itemOpen);
       menu.add(itemSave); 
       menubar.add(menu);  
       setMenuBar(menubar);        
       filedialog_save=new FileDialog(this,"保存文件话框",FileDialog.SAVE);
       filedialog_load=new FileDialog(this,"打开文件话框",FileDialog.LOAD);
       filedialog_save.addWindowListener(new WindowAdapter()
                                  {public void windowClosing(WindowEvent e)
                                       {  filedialog_save.setVisible(false);
                                       }
                                  });
      filedialog_load.addWindowListener(new WindowAdapter()//对话框增加适配器
                                  {public void windowClosing(WindowEvent e)
                                       {  filedialog_load.setVisible(false);
                                       }
                                  });
     addWindowListener(new WindowAdapter() 
                                  {public void windowClosing(WindowEvent e)
                                       {  System.exit(0);}
                                       });
    text=new TextArea(10,10);
    add(text,BorderLayout.CENTER);
	validate();
  }
  public void actionPerformed(ActionEvent e) 
  {  if(e.getSource()==itemOpen)
       {  filedialog_load.setVisible(true);
          text.setText(null);
          String s;
          if(filedialog_load.getFile()!=null)
             {
                try{  File file= new  
                      File(filedialog_load.getDirectory(),filedialog_load.getFile());
                      file_reader=new FileReader(file);
                      in=new BufferedReader(file_reader);
                      while((s=in.readLine())!=null)
                           text.append(s+'\n'); 
                      in.close();
                      file_reader.close();
                   }
               catch(IOException e2){}
             }
        }
     else if(e.getSource()==itemSave)
        {  filedialog_save.setVisible(true);
            if(filedialog_save.getFile()!=null)
              {
                try {
                       File file=new
                       File(filedialog_save.getDirectory(),filedialog_save.getFile());
                       tofile=new FileWriter(file);
                       out=new BufferedWriter(tofile);
                       out.write(text.getText(),0,(text.getText()).length());
                       out.flush();
                       out.close();
                       tofile.close();
                     }
                catch(IOException e2){}
              }
        }
   } 
}