如何使我的 SwingWorker 示例正常工作？

java swing swingworker jdialog

2022-09-03 05:58:32

我制作了自己的SwingWorker示例，以熟悉它的工作原理。

我想做的是以下内容：单击按钮时，我希望在任务完成之前显示进度条，我只想删除进度条并向对话框中添加字符串。

单击该按钮时，进度条会弹出，但永远不会消失。（10 秒后从不移除进度条，也从不放置标签）

这是一个SSCCE：

package swingtesting;

import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JProgressBar;
import javax.swing.SwingWorker;

public class SwingTesting {

    /**
     * Creates a frame that will hold a simple button to make use of SwingWorker
     */
     public static void main(String[] args) {
         // TODO code application logic here
         JFrame frame = new JFrame();
         JButton button = new JButton();

         button.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                new GuiWorker().execute();
            }
         });
         button.setText("Test Me");
         frame.getContentPane().add(button);
         frame.pack();
         frame.setVisible(true);
    }
}

class GuiWorker extends SwingWorker<Integer, Integer> {

    /*
     * This should just create a frame that will hold a progress bar until the
     * work is done. Once done, it should remove the progress bar from the dialog
     * and add a label saying the task complete.
     */

    private JFrame frame = new JFrame();
    private JDialog dialog = new JDialog(frame, "Swingworker test", true);
    private JProgressBar progressBar = new JProgressBar();


    public GuiWorker() {
        progressBar.setString("Waiting on time");
        progressBar.setStringPainted(true);
        progressBar.setIndeterminate(true);
        dialog.getContentPane().add(progressBar);
        dialog.pack();
        dialog.setVisible(true);
    }

    @Override
    protected Integer doInBackground() throws Exception {
        Thread.sleep(10000);
        return 0;
    }

    @Override
    protected void done() {
        JLabel label = new JLabel("Task Complete");
        dialog.getContentPane().remove(progressBar);
        dialog.getContentPane().add(label);
    }

}

答案 1

这是您的代码的更新版本

import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JProgressBar;
import javax.swing.SwingWorker;

public class SwingTesting {

  public static void main(String[] args) {
    EventQueue.invokeLater( new Runnable() {
      @Override
      public void run() {
        JFrame frame = new JFrame();
        JButton button = new JButton();
        button.addActionListener(new ActionListener() {
          @Override
          public void actionPerformed(ActionEvent e) {
            new GuiWorker().execute();
          }
        });
        button.setText("Test Me");
        frame.getContentPane().add(button);
        frame.pack();
        frame.setVisible(true);
      }
    } );

  }
}

class GuiWorker extends SwingWorker<Integer, Integer> {

  /*
  * This should just create a frame that will hold a progress bar until the
  * work is done. Once done, it should remove the progress bar from the dialog
  * and add a label saying the task complete.
  */

  private JFrame frame = new JFrame();
  private JDialog dialog = new JDialog(frame, "Swingworker test", true);
  private JProgressBar progressBar = new JProgressBar();


  public GuiWorker() {
    progressBar.setString("Waiting on time");
    progressBar.setStringPainted(true);
    progressBar.setIndeterminate(true);
    dialog.getContentPane().add(progressBar);
    dialog.pack();
    dialog.setModal( false );
    dialog.setVisible(true);
  }

  @Override
  protected Integer doInBackground() throws Exception {
    System.out.println( "GuiWorker.doInBackground" );
    Thread.sleep(1000);
    return 0;
  }

  @Override
  protected void done() {
    System.out.println("done");
    JLabel label = new JLabel("Task Complete");
    dialog.getContentPane().remove(progressBar);
    dialog.getContentPane().add(label);
    dialog.getContentPane().validate();
  }

}

关键点是设置模型对话框是可见的块，直到对话框被释放。因此，使其非模式固定它+切换组件时内容窗格上的调用。我还调整了您的 main 方法以在 EDT 上运行，并添加了一些 System.out 调用。如果删除调用，您将看到这些语句不会打印，直到您关闭对话框validatesetModal( false )

答案 2

无需使对话框成为非模式对话框。只需在启动 SwingWorker 后显示对话框即可。这可以从调用类（执行 SwingWorker 的类）中完成，方法是首先调用 execute，然后显示对话框，也可以从 SwingWorker 完成，但如果从后者完成，则必须创建自己的伪执行方法，该方法调用 super 的执行，然后显示对话框。请注意，您不能覆盖 execute（）本身，因为它是最终的。

例如。。。

import java.awt.CardLayout;
import java.awt.Window;
import java.awt.Dialog.ModalityType;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.util.concurrent.ExecutionException;

import javax.swing.*;

@SuppressWarnings("serial")
public class SwingTesting2 {

   private static void createAndShowGui() {
      final JFrame frame = new JFrame("SwingTesting2");
      final JDialog dialog = new JDialog(frame, "Dialog",
            ModalityType.APPLICATION_MODAL);
      final DialogPanel dialogPanel = new DialogPanel();
      dialog.getContentPane().add(dialogPanel.getMainPanel());
      dialog.pack();
      dialog.setLocationRelativeTo(frame);

      JButton button = new JButton(new AbstractAction("Test Me") {

         @Override
         public void actionPerformed(ActionEvent actEvt) {
            final GuiWorker2 guiWorker = new GuiWorker2();
            guiWorker.addPropertyChangeListener(new PropertyChangeListener() {

               @Override
               public void propertyChange(PropertyChangeEvent pcEvt) {
                  if (pcEvt.getPropertyName().equals("state")) {
                     if (pcEvt.getNewValue() == SwingWorker.StateValue.DONE) {
                        try {
                           dialogPanel.done(guiWorker.get());
                        } catch (InterruptedException e) {
                           e.printStackTrace();
                        } catch (ExecutionException e) {
                           e.printStackTrace();
                        }
                     }
                  } else if (pcEvt.getPropertyName().equals("progress")) {
                     dialogPanel.setProgress((Integer)pcEvt.getNewValue());
                  }
               }
            });

            guiWorker.execute();
            dialogPanel.start();
            dialog.setVisible(true);
         }
      });

      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(button);
      frame.pack();
      frame.setLocationByPlatform(true);
      frame.setVisible(true);
   }

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

class GuiWorker2 extends SwingWorker<Integer, Integer> {
   private static final int MAX_COUNT = 20;
   private static final long SLEEP_TIME = 100;
   private int count = 0;

   @Override
   protected Integer doInBackground() throws Exception {
      while (count < MAX_COUNT) {
         Thread.sleep(SLEEP_TIME);
         count++;
         setProgress((100 * count) / MAX_COUNT);
      }
      return count;
   }
}

@SuppressWarnings("serial")
class DialogPanel {
   public static final String PROGRESS_BAR = "Progress Bar";
   public static final String DONE = "Done";
   private static final int TIMER_DELAY = 2000;
   private CardLayout cardLayout = new CardLayout();
   private JPanel mainPanel = new JPanel(cardLayout);
   private JLabel doneLabel = new JLabel("Done", JLabel.CENTER);
   private JProgressBar progressBar = new JProgressBar();

   public DialogPanel() {
      progressBar.setString("Waiting on time");
      progressBar.setStringPainted(true);
      progressBar.setIndeterminate(false);

      mainPanel.add(progressBar, PROGRESS_BAR);
      mainPanel.add(doneLabel, DONE);
   }

   public void setProgress(Integer newValue) {
      progressBar.setValue(newValue);
   }

   public void start() {
      cardLayout.show(mainPanel, PROGRESS_BAR);
      progressBar.setValue(0);
   }

   public void done(int countValue) {
      doneLabel.setText(DONE + ". Count: " + countValue);
      cardLayout.show(mainPanel, DONE);
      new Timer(TIMER_DELAY, new ActionListener() {

         @Override
         public void actionPerformed(ActionEvent e) {
            Window win = SwingUtilities.getWindowAncestor(mainPanel);
            win.dispose();
         }
      }){{setRepeats(false);}}.start();
   }

   public JPanel getMainPanel() {
      return mainPanel;
   }

}