在循环(线程)中使JProgressBar更新值的问题

Question

我试图让我的程序在执行某些操作时不断更新方法中的进度条值.然而,直到最后才会发生这种情况,并且UI会冻结.

在查看与我的问题类似的问题后,我尝试实现已接受的解决方案(使用线程)但是我无法使其正常工作.就像他们不在那里一样.

我的程序包含几个类,它们Main是由Netbeans在JFrame 设计模式下自动创建的类,所以有一些东西,比如static void main和public Main那些不确定它的一些内容.在我将把这些方法的片段与我的线程实现一起.

public class Main extends javax.swing.JFrame implements ActionListener, Runnable{
                                          // I added implements ActLis, Runn.....

...

static Main _this;      // I included this variable

...

public static void main(String args[]) {
        Main m = new Main();                               // Added by me
        new Thread(m).start();                             // Added by me
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new Main().setVisible(true);
            }
        });
 }

...

public Main() {
        initComponents();
        _this = this;        // Added by me
}


...

// I also included these 2 methods in the class

public void actionPerformed(ActionEvent e) {                                    
    synchronized(this){                                                         
        notifyAll();                                                            
    }                                                                           
}                                                                               

public void run() {                                                             
    try{synchronized(this){wait();}}
    catch (InterruptedException e){}
    progressBar.setValue(50);                                                   
}

...

private void buttonPressed(java.awt.event.MouseEvent evt) {
   for(int i=0; i<=100; i++) {
      for(int j=0; j<=5; j++) {
         // does some work
      }
   run();
   }
}

I added...根据我在网上看到的教程和答案,我评论的所有内容都是我推出的东西,但似乎没有任何效果,感觉我已经尝试了接近一百万种不同的组合......

在此先感谢您的帮助.

Answer 1

这里有一些基础供您查看,如果您可以研究它并理解为什么每一段代码都存在,那么我认为它会有所帮助.随意在评论中提问(虽然我现在要睡觉了!)

例:

public class ProgressBarDemo extends JFrame {
    private final JProgressBar progressBar = new JProgressBar(0, 100);
    private int progressCounter = 0;

    public ProgressBarDemo() {
        setContentPane(progressBar);
        setPreferredSize(new Dimension(100, 100));
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        pack();
        new Thread(new Runnable() {
            public void run() {
                while (progressCounter <= 100) {
                    SwingUtilities.invokeLater(new Runnable() {
                        public void run() {
                            progressBar.setValue(progressCounter++);
                        }
                    });
                    try { Thread.sleep(500); } catch (InterruptedException e) {}
                }
            }
        }).start();
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new ProgressBarDemo().setVisible(true);
            }
        });
    }
}

使用SwingWorker代替问题的两种不同方法:

SwingWorker示例1:

    ....
    public ProgressBarDemo() {
        setContentPane(progressBar);
        setPreferredSize(new Dimension(100, 100));
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        pack();

        SwingWorker<Integer, Void> worker = new SwingWorker<Integer,Void>() {
            public Integer doInBackground() {
                while (progressCounter <= 100) {
                    setProgress(progressCounter++);
                    try { Thread.sleep(500); } catch (InterruptedException e) {}
                }
                return 0;
            }
        };
        worker.addPropertyChangeListener(new PropertyChangeListener() {
            public void propertyChange(PropertyChangeEvent event) {
                if ("progress".equals(event.getPropertyName())) {
                    progressBar.setValue((Integer)event.getNewValue());
                }
            }
        });
        worker.execute();
    }
    ....

SwingWorker示例2(不太好,但仍然很有趣):

    ....
    public ProgressBarDemo() {
        setContentPane(progressBar);
        setPreferredSize(new Dimension(100, 100));
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        pack();

        new SwingWorker<Integer,Integer>() {
            public Integer doInBackground() { 
                while (progressCounter <= 100) {
                    publish(progressCounter++);
                    try { Thread.sleep(500); } catch (InterruptedException e) {}                    
                }
                return 0;
            }
            public void process(List<Integer> progresses) {
                Integer maxProgress = null;
                for (int progress : progresses) {
                    if (maxProgress == null || progress > maxProgress) {
                        maxProgress = progress;
                    }
                }
                progressBar.setValue(maxProgress);
            }
        }.execute();
    }
    ....