Question

我有一个线程＃1。它显示了MainFrame。
然后，我启动一个线程池以执行一些任务。 线程＃1应该等待线程池完成。我需要显示PopupDialog，它通知现在任务正在进行中。 PopupDialog应该总是仅位于我程序的顶部。
所有任务完成后，应关闭PopupDialog，线程1可以继续执行。

我该怎么做？

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;

/**
 * @see https://stackoverflow.com/questions/24361899/frame-always-on-top-of-my-program-only
 */

public class TopTest {
private static JFrame mainFrame;

public static void main(String[] args) {
    SwingUtilities.invokeLater(new Runnable() {
        @Override
        public void run() {
            mainFrame = new JFrame("test");
            mainFrame.setSize(800, 600);
            mainFrame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
            mainFrame.setVisible(true);

            final PopupDialog popupDialog = new PopupDialog();
            mainFrame.addWindowListener(new WindowAdapter() {
                /**
                 * {@inheritDoc}
                 */
                @Override
                public void windowDeactivated(WindowEvent e) {
                    popupDialog.setAlwaysOnTop(false);
                }

                /**
                 * {@inheritDoc}
                 */
                @Override
                public void windowActivated(WindowEvent e) {
                    popupDialog.setAlwaysOnTop(true);
                }
            });
            startOtherThreads();
            WindowEvent windowClosing = new WindowEvent(popupDialog, WindowEvent.WINDOW_CLOSING);
            popupDialog.dispatchEvent(windowClosing);
        }
    });
}

public static void startOtherThreads() {

    int NUM_THREADS = 8;
    ExecutorService es = Executors.newFixedThreadPool(NUM_THREADS);

    for (int i = 0; i < 5; i++) {
        Task task = new Task();
        es.execute(task); // submit that to be done
    }

    awaitTerminationAfterShutdown(es);

}

static class Task implements Runnable {

    public Task() {
    }

    @Override
    public void run() {

        System.out.println("Each thread waiting for 10 sec");
        try { 
              Thread.sleep(10000);
            } catch(InterruptedException ex) {
              Thread.currentThread().interrupt();
        }
    }
}

public static void awaitTerminationAfterShutdown(ExecutorService threadPool) {
    threadPool.shutdown();
    try {
        if (!threadPool.awaitTermination(300, TimeUnit.SECONDS)) {
            threadPool.shutdownNow();
        }
    } catch (InterruptedException ex) {
        threadPool.shutdownNow();
        Thread.currentThread().interrupt();
    }
}

public static class PopupDialog extends JDialog {

    public PopupDialog() {
        super(mainFrame);

        JLabel label = new JLabel("Waiting for thread pool completion...");
        getContentPane().add(label, BorderLayout.CENTER);
        setAlwaysOnTop(true);
        setFocusable(false);
        setPreferredSize(new Dimension(300, 100));
        pack();
        setLocationRelativeTo(mainFrame);
        setVisible(true);
    }
}
}

目前，PopupDialog位于所有程序的顶部（当所有其他线程正在执行时，我无法监听线程＃1）。而且PopupDialog没有显示它的内容。

如何仅使用多线程使框架始终位于程序顶部

0 个答案: