java - 当我在我的 GUI 上播放歌曲时，JButton 一直被按下，我无法点击任何东西

Question

我写了一个程序，它基本上是一个图片幻灯片放映，也显示文本和播放音乐。一切正常，除非我按下名为“播放歌曲”的 JButton。当我按下此按钮时，歌曲开始播放，但按钮仍处于按下状态，我无法在 GUI 中单击任何内容。我加载歌曲的方式有一个数组，其中包含选定文件夹中文件的所有路径名，然后我使用 FileInputStream 使用数组中的路径名加载文件。一旦文件被加载，它就会被播放。我认为这是读取 .mp3 文件并播放它们的最佳方式，因为我采用了类似的方法来读取选定文件夹中的所有图像，并且效果很好。任何帮助将不胜感激!这是包含我的主要方法的文件，它包含创建 GUI 的类，并包含除播放音乐之外的所有方法:

import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.io.*;
import java.net.URL;
import java.util.*;
import javax.imageio.*;
import javax.swing.*;
@SuppressWarnings("serial")
public class Aubs extends JFrame
{
  static File pics[] = null;
  JLabel label;
  JPanel panel;
  JTextArea quoteDisplay, imageDisplay;
  JButton newQuote, newBC, newText, song;
  ArrayList<String> quotes = new ArrayList<String>();
  public Aubs()
  {
     loadPics(); 
     panel = new JPanel();
     panel.setLayout(null);
     panel.setBackground(Background()); 
     add(panel);

     label = new JLabel(); 
     setPics();
     changePic e = new changePic();
     label.addMouseListener(e);
     panel.addMouseListener(e);

     song = new JButton("Play Song"); // The button to change song
     song.setBounds(1000,115,185,30);
     song.addActionListener(new Song()); // Add ActionListener 
     panel.add(song); // Adds the button to the screen

     imageDisplay = new JTextArea("Click the image for a new one");
     imageDisplay.setBounds(630,30,300,300);
     imageDisplay.setFont(new Font("FatFrank",Font.BOLD,16));
     imageDisplay.setForeground(Font()); // Sets the font color
     imageDisplay.setOpaque(false);
     imageDisplay.setEditable(false);
     panel.add(imageDisplay);
     panel.setBackground(Background()); 

     quoteDisplay = new JTextArea();
     setQuotes();

     newQuote = new JButton("Quote");
     newQuote.setBounds(1000,0,185,40);
     newQuote.addActionListener(new changeQuote()); 
     newQuote.setForeground(Color.BLACK); 
     panel.add(newQuote);

     newBC = new JButton("New Background Color");
     newBC.setBounds(1000,90,185,30);
     newBC.addActionListener(new newBack());
     newBC.setForeground(Color.BLACK);
     panel.add(newBC);

     newText = new JButton("New Font color");
     newText.setBounds(1000,65,185,30);
     newText.addActionListener(new newFont());
     newText.setForeground(Color.BLACK);
     panel.add(newText);    


 }
 private void loadPics()
 {
    JFileChooser choose = new JFileChooser();
    choose.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
    int status = choose.showOpenDialog(null);
    if (status == JFileChooser.APPROVE_OPTION) 
    {
         File dir = choose.getSelectedFile(); 
            if (dir.exists()) 
            {
                pics = dir.listFiles(new FileFilter()
                {
                     @Override
                        public boolean accept(File pathname) 
                        {
                            String name = pathname.getName().toLowerCase();
                            return name.endsWith(".png")
                                    || name.endsWith(".jpg")
                                    || name.endsWith(".jpeg")
                                    || name.endsWith(".bmp")
                                    || name.endsWith(".gif");
                        }
                });
            }
    }
}
private void setPics()
{
    int i = (int)(Math.random()*pics.length); // Chooses a number for index
    try 
    {
        BufferedImage buff = ImageIO.read(pics[i]); // Reads in the image
        ImageIcon icon = new ImageIcon(buff); // Converts it to an ImageIcon
        icon = transform(icon); // Resizes
        label.setIcon(icon);
        label.setBounds(10,10,600,700); 
        panel.add(label);
        panel.setBackground(Background());
    } 
    catch (IOException e) 
    {
        e.printStackTrace();
    }
}

private ImageIcon transform(ImageIcon x) // Resizes the Image
{
    ImageIcon temp = x;
    Image image = temp.getImage();
    Image tempImg = image.getScaledInstance(600,700,java.awt.Image.SCALE_SMOOTH );
    temp = new ImageIcon(tempImg);
    return temp;
}
private void loadQuotes()
{
    URL url = getClass().getResource("Quotes/Quotes.txt");
    try{    
        Scanner scan = new Scanner(new FileInputStream(url.getPath()));

        while(scan.hasNextLine())
        {   
            quotes.add(scan.nextLine());
        }
        scan.close();
    }
    catch(Exception ex)
    {
        System.out.println("File not found");
    }
}
private void setQuotes()
{
    loadQuotes();
    int q = (int)(Math.random()*quotes.size());
    quoteDisplay.setText(quotes.get(q));
    quoteDisplay.setBounds(650,100,200,400);
    quoteDisplay.setFont(new Font("FatFrank",Font.BOLD,16));
    quoteDisplay.setForeground(Font());
    quoteDisplay.setLineWrap(true);
    quoteDisplay.setWrapStyleWord(true);
    quoteDisplay.setOpaque(false);
    quoteDisplay.setEditable(false);
    panel.setBackground(Background());
    panel.add(quoteDisplay);
    imageDisplay.setBackground(Background());
}
private Color Font()
{
    int r = (int)(Math.random() *256);
    int g = (int)(Math.random() *256);
    int b = (int)(Math.random() *256);
    return (new Color(r, g, b).brighter());
}
private Color Background()
{
    int r = (int)(Math.random() *256);
    int g = (int)(Math.random() *256);
    int b = (int)(Math.random() *256);
    return (new Color(r, g, b).darker());
}
public void playSong()
{
    MP3 play = new MP3(); // Creates and object of MP3
    play.play(); // Calles the play method in MP3
}
private class changePic implements MouseListener
{
    public void mouseClicked(MouseEvent e) 
    {
        setPics();
        quoteDisplay.setForeground(Font());
        imageDisplay.setForeground(Background());
    }
    public void mousePressed(MouseEvent e) {}
    public void mouseReleased(MouseEvent e) {}
    public void mouseEntered(MouseEvent e) {}
    public void mouseExited(MouseEvent e){}
}
private class changeQuote implements ActionListener
{
    public void actionPerformed(ActionEvent q) 
    {
        setQuotes();
    }
}
private class newBack implements ActionListener
{
    public void actionPerformed(ActionEvent bc) 
    {
        panel.setBackground(Background());
    }       
}
private class newFont implements ActionListener
{
    public void actionPerformed(ActionEvent fc) 
    {
        quoteDisplay.setForeground(Font());
        imageDisplay.setForeground(Font());
    }
}
public class Song implements ActionListener // Supposes to change the song when a button is pressed
{
    public void actionPerformed(ActionEvent s) 
    {
        playSong();
    }   
}
public static void main(String[] args)
{
    Aubs aubs = new Aubs();
    aubs.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    aubs.setSize(new Dimension(1200, 1000));
    aubs.setVisible(true);
}

}这是播放音乐的类:

import javazoom.jl.player.*;
import java.io.*;
import java.util.ArrayList;
public class MP3 
{   
  static File list[] = null;
  ArrayList<Player> songs = new ArrayList<Player>();
  public void play()
  { 
     MP3Files(); // Loads the pathnames to the array list[].
     int i = 0; // Will be the count of the files loaded in
     int x = (int)(Math.random()*i); 
     try
    { 
        Player cur;
        if(i >= list.length-1) // True when all files are loaded,
        {
            cur = songs.get(x); // Then it chooses a random song 
            cur.play(); // Play that song
        }
        else // True when not all files from list[] are loaded,
        {
            FileInputStream in = new FileInputStream(list[i]); 
            songs.add(new Player(in)); //add the song to theArrayList. 
            cur = songs.get(x); // Get random song
            cur.play(); // Play random song
            i++;
        }
    }
    catch(Exception e)
    {
        System.out.println("Error");
    }
}       
public static void MP3Files() // Loads all the pathnames 
{
    File dir = new File("/Users/mine/Desktop/Music"); 
    if(dir.isDirectory())
    {
        list = dir.listFiles(new FileFilter() // the pathnames.
        {
            @Override
             public boolean accept(File pathname) 
             {
                String name = pathname.getName().toLowerCase();
                return name.endsWith(".mp3");

             }
         });
    }
}

Answer 1

When I press this button the songs play but the button remains pressed and I can't click and anything in GUI.

从监听器调用的代码在 Event Dispatch Thread (EDT) 上执行，该线程负责绘制 GUI。

如果您随后调用一个长时间运行的任务，您将阻止 EDT，这意味着 GUI 无法响应任何更多事件或重新绘制自身，直到任务完成。

您需要启动一个单独的Thread 来播放您的歌曲。

阅读 Concurrency 上的 Swing 教程部分有关 EDT 的更多信息。您可以创建自己的 Thread，也可以使用教程中描述的 SwingWorker(它会为您创建 Thread)，具体取决于您的具体要求。