制作一个显示“Please Wait”JDialog的swing线程

Question

问题是这样的：
我有一个摆动应用程序正在运行，在某一点上，一个对话框需要插入用户名和密码并按“确定”。
我希望当用户按“确定”时，摆动应用程序按以下顺序执行：

1. 打开“请稍候”JDialog
2. 进行一些操作（最终显示一些其他JDialog或JOptionPane）
3. 操作完成后，关闭“please wait”（请等待）JDialog
   

这是我在okButtonActionPerformed（）中编写的代码：

private void okButtonActionPerformed(java.awt.event.ActionEvent evt) { 
    //This class simply extends a JDialog and contains an image and a jlabel (Please wait)
    final WaitDialog waitDialog = new WaitDialog(new javax.swing.JFrame(), false);    
    waitDialog.setVisible(true);
    ... //Do some operation (eventually show other JDialogs or JOptionPanes)
    waitDialog.dispose()
}

这段代码显然不起作用，因为当我在同一个线程中调用waitDialog时，它会阻塞所有内容，直到我不关闭它为止<所以我试着在不同的线程中运行它：

private void okButtonActionPerformed(java.awt.event.ActionEvent evt) { 
    //This class simply extends a JDialog and contains an image and a jlabel (Please wait)
    final WaitDialog waitDialog = new WaitDialog(new javax.swing.JFrame(), false);    
    SwingUtilities.invokeLater(new Runnable() {
        @Override
        public void run() {
            waitDialog.setVisible(true);
        }
    });
    ... //Do some operation (eventually show other JDialogs or JOptionPanes)
    waitDialog.dispose()
}

但是这也不起作用，因为waitDialog不会立即显示，而是在操作完成后才显示（当它们显示jption窗格“您以...”）

我还尝试使用invokeAndWait而不是invokeLater，但在这种情况下，它引发了一个异常：

Exception in thread "AWT-EventQueue-0" java.lang.Error: Cannot call invokeAndWait from the event dispatcher thread

我该怎么做？

Answer 1

上述答案的变体

这是一种简单且可复制的方法。。。

//This code goes inside your button action   
DialogWait wait = new DialogWait();

SwingWorker<Void, Void> mySwingWorker = new SwingWorker<Void, Void>() {

    @Override
    protected Void doInBackground() throws Exception {

        //Here you put your long-running process...

        wait.close();
        return null;
    }
};

mySwingWorker.execute();
wait.makeWait("Test", evt);
//end


//Create this class on your project
class DialogWait {

private JDialog dialog;

public void makeWait(String msg, ActionEvent evt) {

    Window win = SwingUtilities.getWindowAncestor((AbstractButton) evt.getSource());
    dialog = new JDialog(win, msg, Dialog.ModalityType.APPLICATION_MODAL);

    JProgressBar progressBar = new JProgressBar();
    progressBar.setIndeterminate(true);
    JPanel panel = new JPanel(new BorderLayout());
    panel.add(progressBar, BorderLayout.CENTER);
    panel.add(new JLabel("Please wait......."), BorderLayout.PAGE_START);
    dialog.add(panel);
    dialog.pack();
    dialog.setLocationRelativeTo(win);
       dialog.setVisible(true);
   }

   public void close() {
       dialog.dispose();
   }
}

Answer 2

public void okButtonActionPerformed(ActionEvent e) {

    final JDialog loading = new JDialog(parentComponent);
    JPanel p1 = new JPanel(new BorderLayout());
    p1.add(new JLabel("Please wait..."), BorderLayout.CENTER);
    loading.setUndecorated(true);
    loading.getContentPane().add(p1);
    loading.pack();
    loading.setLocationRelativeTo(parentComponent);
    loading.setDefaultCloseOperation(JDialog.DO_NOTHING_ON_CLOSE);
    loading.setModal(true);

    SwingWorker<String, Void> worker = new SwingWorker<String, Void>() {
        @Override
        protected String doInBackground() throws InterruptedException 
            /** Execute some operation */   
        }
        @Override
        protected void done() {
            loading.dispose();
        }
    };
    worker.execute();
    loading.setVisible(true);
    try {
        worker.get();
    } catch (Exception e1) {
        e1.printStackTrace();
    }
}

Answer 3

考虑使用SwingWorker做后台工作，然后在SwingWorker的done（）方法或添加到SwingWorker的PropertyChangeListener（我的首选）中关闭对话框。

例如。，

import java.awt.BorderLayout;
import java.awt.Dialog.ModalityType;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;    
import javax.swing.*;

public class PleaseWaitEg {
   public static void main(String[] args) {
      JButton showWaitBtn = new JButton(new ShowWaitAction("Show Wait Dialog"));
      JPanel panel = new JPanel();
      panel.add(showWaitBtn);
      JFrame frame = new JFrame("Frame");
      frame.getContentPane().add(panel);
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.pack();
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);

   }
}

class ShowWaitAction extends AbstractAction {
   protected static final long SLEEP_TIME = 3 * 1000;

   public ShowWaitAction(String name) {
      super(name);
   }

   @Override
   public void actionPerformed(ActionEvent evt) {
      SwingWorker<Void, Void> mySwingWorker = new SwingWorker<Void, Void>(){
         @Override
         protected Void doInBackground() throws Exception {

            // mimic some long-running process here...
            Thread.sleep(SLEEP_TIME);
            return null;
         }
      };

      Window win = SwingUtilities.getWindowAncestor((AbstractButton)evt.getSource());
      final JDialog dialog = new JDialog(win, "Dialog", ModalityType.APPLICATION_MODAL);

      mySwingWorker.addPropertyChangeListener(new PropertyChangeListener() {

         @Override
         public void propertyChange(PropertyChangeEvent evt) {
            if (evt.getPropertyName().equals("state")) {
               if (evt.getNewValue() == SwingWorker.StateValue.DONE) {
                  dialog.dispose();
               }
            }
         }
      });
      mySwingWorker.execute();

      JProgressBar progressBar = new JProgressBar();
      progressBar.setIndeterminate(true);
      JPanel panel = new JPanel(new BorderLayout());
      panel.add(progressBar, BorderLayout.CENTER);
      panel.add(new JLabel("Please wait......."), BorderLayout.PAGE_START);
      dialog.add(panel);
      dialog.pack();
      dialog.setLocationRelativeTo(win);
      dialog.setVisible(true);
   }
}

注意：

• 一个关键的概念是在显示模式对话框之前设置一切，添加PropertyChangeListener，运行SwingWorker，因为一旦显示了模式对话框，调用代码的所有代码流都将冻结（正如您所发现的）