初学者问题！ 请指点！1

Question

打开保存文件的对话框应该用 JFileChooser类import java.awt.event.*;
import javax.swing.*;public class OpenDialog extends JFrame implements ActionListener 
       {
        JButton open = new JButton("打开");
        JFileChooser chooser = new JFileChooser();
        
        public OpenDialog()
              {
               super("打开");
               setSize(300,350);
               setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
               
               JPanel pane = new JPanel();
                      open.addActionListener(this);      
                      pane.add(open);
               setContentPane(pane);
              }
    
              public void main(String[] args)
                     {
                      int state = chooser.showOpenDialog(null);
                      File file = chooser.getSeletedFile();
                      String s = "CANCELED";
                      
                      if (file!=null && state==JFileChooser.APPPOVE_OPTION)
                          {s=file.getPath();
                            // 这里加入文件输入流 （便可完成打开一个文件）
                          }
                      JOptionPane.showMessageDialog(null,s);
                      }
             }             不知道这是不是你想要的！

Answer 1

啊发现了不好意思 忘记了事件处理import java.awt.event.*;
import javax.swing.*;public class OpenDialog extends JFrame implements ActionListener 
       {
        JButton open = new JButton("打开");
        JFileChooser chooser = new JFileChooser();
        
        public OpenDialog()
              {
               super("打开");
               setSize(300,350);
               setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
               
               JPanel pane = new JPanel();
                      open.addActionListener(this);      
                      pane.add(open);
               setContentPane(pane);
              }
              
              public static void main(String[] args)
                     {
                        OpenDialog  opendialog = new OpenDialog();
                                    opendialog.show();
                     }
    
              public void actionPerformed(ActionEvent e)
                     {
                      int state = chooser.showOpenDialog(null);
                      File file = chooser.getSeletedFile();
                      String s = "CANCELED";
                      
                      if (file!=null && state==JFileChooser.APPPOVE_OPTION)
                          {s=file.getPath();
                            // 这里加入文件输入流 （便可完成打开一个文件）
                          }
                      JOptionPane.showMessageDialog(null,s);
                      }
             }

Answer 2

if (file!=null && state==JFileChooser.APPPOVE_OPTION) 
修改成if (file!=null && state==JFileChooser.APPROVE_OPTION)由于我在网吧上网 没有调试环境程序会存在一些错误 最好能明白我的思路 然后去创建自己的程序

Answer 3

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;public class OpenDialog extends JFrame implements ActionListener 
       {
        JButton open = new JButton("打开");
        JFileChooser chooser = new JFileChooser();
        
        public OpenDialog()
              {
               super("打开");
               setSize(300,350);
               setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
               
               JPanel pane = new JPanel();
                      open.addActionListener(this);  
                      pane.add(text);    
                      pane.add(open);
               setContentPane(pane);
              }
              
              public static void main(String[] args)
                     {
                        OpenDialog  opendialog = new OpenDialog();
                                    opendialog.show();
                     }
    
              public void actionPerformed(ActionEvent e)
                     {
                      int state = chooser.showOpenDialog(null);
                      File file = chooser.getSelectedFile();                      if (file!=null && state==JFileChooser.APPROVE_OPTION)
                          {
                            try{
                               FileWriter filew = new FileWriter(file);
                               BufferedWriter buff = new BufferedWriter(filew);
                               boolean eof = false;
                               while(!eof)
                                    {
                                     String line = buff.readLine();
                                     if (line==null)
                                        eof=true;
                                     else 
                                        System.out.Println(line);
                                     }
                                     buff.close();  
                           
                              }catch(IOException e) {System.out.printf      ("Error:"+e.toMessage());}
                           
                                                                  
                           }
                     }
             }如果有错误请与我联系 最好找一个关于JAVA IO的文档看一下,就会明白了