FileDialog的使用

文本编辑器1.0

1、打开文件（基本格式文件，如txt/cpp/c/java等等）
2、保存编辑区文本到文件中（程序save方法中设置的txt文件）

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

public class Demo08 extends JFrame implements ActionListener{
    
    

	JTextArea tArea = new JTextArea(20,40);
	JScrollPane scroll = new JScrollPane(tArea); // JScrollpane滚动面板，为JTextArea添加滚动条
	Button btn1 = new Button("open");
	Button btn2 = new Button("save");
	
	public Demo08() {
    
    
	    super("文本编辑器1.0");
		setBounds(10, 10, 700, 500);
		setVisible(true);
		setDefaultCloseOperation(EXIT_ON_CLOSE);
		setLayout(new FlowLayout());
		
		btn1.addActionListener(this);
		btn2.addActionListener(this);
		add(btn1);
		add(btn2);
//		add(tArea);
		getContentPane().add(scroll);
		
		scroll.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
		scroll.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
	}
	
	public static void main(String[] args) {
    
    
		new Demo08();
	}

	@Override
	public void actionPerformed(ActionEvent e) {
    
    
		if (e.getSource() == btn1) {
    
    
			FileDialog fdopen = new FileDialog(this,"打开",FileDialog.LOAD);
			fdopen.setVisible(true);
			tArea.setText("");
			try {
    
    
				BufferedReader reader = new BufferedReader(new FileReader(fdopen.getDirectory()+fdopen.getFile()));
				String str = reader.readLine();
				while(str!=null) {
    
    
					tArea.append(str+'\n');
					str = reader.readLine();
				}
				reader.close();
			} catch (Exception e1) {
    
    
//				e1.printStackTrace();
			}
		}
		if (e.getSource() == btn2) {
    
    
			FileDialog fdsave = new FileDialog(this,"保存",FileDialog.SAVE);
			fdsave.setVisible(true);
			
			String path = fdsave.getDirectory()+fdsave.getFile()+".txt";
			try {
    
    
				BufferedWriter writer = new BufferedWriter(new FileWriter(path));
				writer.write(tArea.getText());
				
				writer.close();
			} catch (IOException e1) {
    
    
				e1.printStackTrace();
			}
		}
	}
}

FileDialog类

1、构造方法

2、设置文件对话框可见⭐
setVisible(boolean)

3、常用方法