在后台作业时禁用JButton以避免多次单击

Question

我需要阻止用户在第一次点击仍然执行时对JButton进行多次点击.

我能够为这个问题找到解决方案,但我并不完全理解为什么它会起作用.

贝娄我发布了有效的代码(修剪到最小)和不起作用的代码.

在第一个示例中(好)如果您运行它并多次单击该按钮,则只考虑一个操作,对于第二个示例(坏),如果多次单击鼠标,则至少执行两次操作.

第二个(坏)示例根本不使用invokeLater()方法.

行为的差异来自哪里？

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.*;

public class TestButtonTask {

    public static void main(String[] args) {

        final JFrame frame = new JFrame("Test");
        frame.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);

        final JButton task = new JButton("Test");

        task.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                long t = System.currentTimeMillis();
                System.out.println("Action received");

                task.setText("Working...");
                task.setEnabled(false);

                SwingUtilities.invokeLater(new Thread() {

                    @Override
                    public void run() {
                        try {
                            sleep(2 * 1000);
                        } catch (InterruptedException ex) {
                            Logger.getLogger(TestButtonTask.class.getName()).log(Level.SEVERE, null, ex);
                        }

                        SwingUtilities.invokeLater(new Runnable() {

                            public void run() {
                                task.setEnabled(true);
                                task.setText("Test");
                            }
                        });

                    }
                });
            }
        });

        frame.add(task);
        frame.pack();
        frame.setVisible(true);
    } //end main
} //end class

现在是"错误的"代码

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.*;

public class TestButtonTask {

    public static void main(String[] args) {

        final JFrame frame = new JFrame("Test");
        frame.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);

        final JButton task = new JButton("Test");

        task.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                long t = System.currentTimeMillis();
                System.out.println("Action received");

                task.setText("Working...");
                task.setEnabled(false);

                SwingUtilities.invokeLater(new Thread() {

                    @Override
                    public void run() {
                        try {
                            sleep(2 * 1000);
                        } catch (InterruptedException ex) {
                            Logger.getLogger(TestButtonTask.class.getName()).log(Level.SEVERE, null, ex);
                        }

                        //SwingUtilities.invokeLater(new Runnable() {

                            //public void run() {
                                task.setEnabled(true);
                                task.setText("Test");
                            //}
                        //});

                    }
                });
            }
        });

        frame.add(task);
        frame.pack();
        frame.setVisible(true);
    } //end main
} //end class

在@kleopatra和@BorisPavlović提供的信息之后,我创建的代码看起来相当不错.

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.*;

public class TestButtonTask {

    public static void main(String[] args) {

        final JFrame frame = new JFrame("Test");
        frame.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);

        final JButton task = new JButton("Test");

        task.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                task.setText("Working...");
                task.setEnabled(false);

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

                    @Override
                    protected Void doInBackground() throws Exception {
                        try {
                            Thread.sleep(3 * 1000);
                        } catch (InterruptedException ex) {
                            Logger.getLogger(TestButtonTask.class.getName()).log(Level.SEVERE, null, ex);
                        }

                        return null;
                    }                    
                };

                worker.addPropertyChangeListener(new PropertyChangeListener() {
                    @Override
                    public void propertyChange(PropertyChangeEvent evt) {
                        System.out.println("Event " + evt + " name" + evt.getPropertyName() + " value " + evt.getNewValue());
                        if ("DONE".equals(evt.getNewValue().toString())) {
                            task.setEnabled(true);
                            task.setText("Test");
                        }
                    }
                });

                worker.execute();
            }
        });

        frame.add(task);
        frame.pack();
        frame.setVisible(true);
    } //end main
} //end class

Answer 1

你有两个选择

1)JButton#setMultiClickThreshhold

2)你必须将这个想法分解为actionListener或Action中的两个独立动作

• 1.step,JButton#setEnabeld(false);
• 第2位.步骤,然后调用其余代码包装javax.swing.Action(来自和分析 javax.swing.Timer),SwingWorker或Runnable#Thread