0

（完整的源代码在底部）

所以很长一段时间以来，我一直在研究这个问题。我有一个最终目标，但为了学习如何做到这一点，我创建了一个应用程序，它只需将一个数字加 1 并显示为jLabel1每秒。我的问题是我无法Timer工作。

我的研究向我展示了Timer使用包java.util.timer和javax.swing.timer. 迄今为止，它们都没有奏效。这绝不是代码错误的问题，但似乎没有调用某些方法。在我的大多数试验中，它通常归结为方法 Schedule。在我最近的尝试中，它归结为：

new Timer(delay, taskPerformer).start();

一直给我这个问题。原来的错误是

illegal start of type

invalid method declaration; return type required

cannot find symbol
  symbol:   class delay
  location: class timer.TimerView.two

<identifier> expected

cannot find symbol
  symbol:   class taskPerformer
  location: class timer.TimerView.two

<identifier> expected

';' expected

好延迟明确定义为整数，但即使我用 1000 替换延迟它告诉我

illegal start of type

invalid method declaration; return type required

illegal start of type

所以现在我很茫然。我看了又看，我见过很多成功的故事，但他们几乎从不使用 netbeans 默认 bs。我无法导入java.util.timer，因为据我了解javax.swing.timer导入它本身或一些废话。

我很少寻求帮助，但在查找此内容的几个小时内，我得到了与 36 小时前完全相同的源代码，其中有一堆橡皮擦。所以我真的希望至少有人能指出我正确的方向。我已经查看了 Oricals 教程等。这总是把我留在同一个地方。我尝试过操作其他使用计时器功能的程序，甚至尝试对 netbeans 中空白桌面应用程序附带的状态栏进行逆向工程。似乎没有什么想要工作。或者更有可能的是，我的经验不足让我找错了地方。从我的角度来看，这并不是一个罕见的问题，但我无法让它发挥作用。下面发布的是我的完整程序，由于其简单的性质，它与空白的 netbeans 应用程序相距不远。

/*
 * TimerView.java
 */

package timer;

import org.jdesktop.application.Action;
import org.jdesktop.application.ResourceMap;
import org.jdesktop.application.SingleFrameApplication;
import org.jdesktop.application.FrameView;
import org.jdesktop.application.TaskMonitor;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.Timer;
import javax.swing.Icon;
import javax.swing.JDialog;
import javax.swing.JFrame;

/**
 * The application's main frame.
 */
public class TimerView extends FrameView {

    public TimerView(SingleFrameApplication app) {
        super(app);

        initComponents();

        // status bar initialization - message timeout, idle icon and busy animation, etc
        ResourceMap resourceMap = getResourceMap();
        int messageTimeout = resourceMap.getInteger("StatusBar.messageTimeout");
        messageTimer = new Timer(messageTimeout, new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                statusMessageLabel.setText("");
            }
        });
        messageTimer.setRepeats(false);
        int busyAnimationRate = resourceMap.getInteger("StatusBar.busyAnimationRate");
        for (int i = 0; i < busyIcons.length; i++) {
            busyIcons[i] = resourceMap.getIcon("StatusBar.busyIcons[" + i + "]");
        }
        busyIconTimer = new Timer(busyAnimationRate, new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                busyIconIndex = (busyIconIndex + 1) % busyIcons.length;
                statusAnimationLabel.setIcon(busyIcons[busyIconIndex]);
            }
        });
        idleIcon = resourceMap.getIcon("StatusBar.idleIcon");
        statusAnimationLabel.setIcon(idleIcon);
        progressBar.setVisible(false);

        // connecting action tasks to status bar via TaskMonitor
        TaskMonitor taskMonitor = new TaskMonitor(getApplication().getContext());
        taskMonitor.addPropertyChangeListener(new java.beans.PropertyChangeListener() {
            public void propertyChange(java.beans.PropertyChangeEvent evt) {
                String propertyName = evt.getPropertyName();
                if ("started".equals(propertyName)) {
                    if (!busyIconTimer.isRunning()) {
                        statusAnimationLabel.setIcon(busyIcons[0]);
                        busyIconIndex = 0;
                        busyIconTimer.start();
                    }
                    progressBar.setVisible(true);
                    progressBar.setIndeterminate(true);
                } else if ("done".equals(propertyName)) {
                    busyIconTimer.stop();
                    statusAnimationLabel.setIcon(idleIcon);
                    progressBar.setVisible(false);
                    progressBar.setValue(0);
                } else if ("message".equals(propertyName)) {
                    String text = (String)(evt.getNewValue());
                    statusMessageLabel.setText((text == null) ? "" : text);
                    messageTimer.restart();
                } else if ("progress".equals(propertyName)) {
                    int value = (Integer)(evt.getNewValue());
                    progressBar.setVisible(true);
                    progressBar.setIndeterminate(false);
                    progressBar.setValue(value);
                }
            }
        });
    }

    @Action
    public void showAboutBox() {
        if (aboutBox == null) {
            JFrame mainFrame = TimerApp.getApplication().getMainFrame();
            aboutBox = new TimerAboutBox(mainFrame);
            aboutBox.setLocationRelativeTo(mainFrame);
        }
        TimerApp.getApplication().show(aboutBox);
    }

    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {

        mainPanel = new javax.swing.JPanel();
        jLabel1 = new javax.swing.JLabel();
        menuBar = new javax.swing.JMenuBar();
        javax.swing.JMenu fileMenu = new javax.swing.JMenu();
        javax.swing.JMenuItem exitMenuItem = new javax.swing.JMenuItem();
        javax.swing.JMenu helpMenu = new javax.swing.JMenu();
        javax.swing.JMenuItem aboutMenuItem = new javax.swing.JMenuItem();
        statusPanel = new javax.swing.JPanel();
        javax.swing.JSeparator statusPanelSeparator = new javax.swing.JSeparator();
        statusMessageLabel = new javax.swing.JLabel();
        statusAnimationLabel = new javax.swing.JLabel();
        progressBar = new javax.swing.JProgressBar();

        mainPanel.setName("mainPanel"); // NOI18N

        org.jdesktop.application.ResourceMap resourceMap = org.jdesktop.application.Application.getInstance(timer.TimerApp.class).getContext().getResourceMap(TimerView.class);
        jLabel1.setText(resourceMap.getString("jLabel1.text")); // NOI18N
        jLabel1.setName("jLabel1"); // NOI18N

        javax.swing.GroupLayout mainPanelLayout = new javax.swing.GroupLayout(mainPanel);
        mainPanel.setLayout(mainPanelLayout);
        mainPanelLayout.setHorizontalGroup(
            mainPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(mainPanelLayout.createSequentialGroup()
                .addGap(178, 178, 178)
                .addComponent(jLabel1)
                .addContainerGap(188, Short.MAX_VALUE))
        );
        mainPanelLayout.setVerticalGroup(
            mainPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(mainPanelLayout.createSequentialGroup()
                .addGap(107, 107, 107)
                .addComponent(jLabel1)
                .addContainerGap(133, Short.MAX_VALUE))
        );

        menuBar.setName("menuBar"); // NOI18N

        fileMenu.setText(resourceMap.getString("fileMenu.text")); // NOI18N
        fileMenu.setName("fileMenu"); // NOI18N

        javax.swing.ActionMap actionMap = org.jdesktop.application.Application.getInstance(timer.TimerApp.class).getContext().getActionMap(TimerView.class, this);
        exitMenuItem.setAction(actionMap.get("quit")); // NOI18N
        exitMenuItem.setName("exitMenuItem"); // NOI18N
        fileMenu.add(exitMenuItem);

        menuBar.add(fileMenu);

        helpMenu.setText(resourceMap.getString("helpMenu.text")); // NOI18N
        helpMenu.setName("helpMenu"); // NOI18N

        aboutMenuItem.setAction(actionMap.get("showAboutBox")); // NOI18N
        aboutMenuItem.setName("aboutMenuItem"); // NOI18N
        helpMenu.add(aboutMenuItem);

        menuBar.add(helpMenu);

        statusPanel.setName("statusPanel"); // NOI18N

        statusPanelSeparator.setName("statusPanelSeparator"); // NOI18N

        statusMessageLabel.setName("statusMessageLabel"); // NOI18N

        statusAnimationLabel.setHorizontalAlignment(javax.swing.SwingConstants.LEFT);
        statusAnimationLabel.setName("statusAnimationLabel"); // NOI18N

        progressBar.setName("progressBar"); // NOI18N

        javax.swing.GroupLayout statusPanelLayout = new javax.swing.GroupLayout(statusPanel);
        statusPanel.setLayout(statusPanelLayout);
        statusPanelLayout.setHorizontalGroup(
            statusPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(statusPanelSeparator, javax.swing.GroupLayout.DEFAULT_SIZE, 400, Short.MAX_VALUE)
            .addGroup(statusPanelLayout.createSequentialGroup()
                .addContainerGap()
                .addComponent(statusMessageLabel)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 230, Short.MAX_VALUE)
                .addComponent(progressBar, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(statusAnimationLabel)
                .addContainerGap())
        );
        statusPanelLayout.setVerticalGroup(
            statusPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(statusPanelLayout.createSequentialGroup()
                .addComponent(statusPanelSeparator, javax.swing.GroupLayout.PREFERRED_SIZE, 2, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addGroup(statusPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(statusMessageLabel)
                    .addComponent(statusAnimationLabel)
                    .addComponent(progressBar, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(3, 3, 3))
        );

        setComponent(mainPanel);
        setMenuBar(menuBar);
        setStatusBar(statusPanel);
    }// </editor-fold>




   public class two {



        int delay = 1000;
  ActionListener taskPerformer = new ActionListener() {
      public void actionPerformed(ActionEvent evt) {

          int Number = 0;
          String Output;
          Number++;
          Output = Integer.toString(Number);
          jLabel1.setText(Output);
      }
  };
  new Timer(1000, taskPerformer).start();


   }







    // Variables declaration - do not modify
    private javax.swing.JLabel jLabel1;
    private javax.swing.JPanel mainPanel;
    private javax.swing.JMenuBar menuBar;
    private javax.swing.JProgressBar progressBar;
    private javax.swing.JLabel statusAnimationLabel;
    private javax.swing.JLabel statusMessageLabel;
    private javax.swing.JPanel statusPanel;
    // End of variables declaration

    private final Timer messageTimer;
    private final Timer busyIconTimer;
    private final Icon idleIcon;
    private final Icon[] busyIcons = new Icon[15];
    private int busyIconIndex = 0;

    private JDialog aboutBox;
}
4

2 回答 2

2

1）我建议使用javax.swing.Timer而不是java.util.Timer，因为输出javax.swing.Timer总是在 EDT

2)java.util.Timer必须将来自 GUI 的输出包装到invokeLater中，否则无法保证任何内容都应该被显示/更改/重新绘制

3）有关更多信息，您必须阅读Swing 中的 Concurency

4）我建议手动创建你的代码，而不是使用 un-suppotedJava Desktop Application和layed by using GroupLayout，

于 2011-12-13T09:06:53.527 回答
0

你是这样开始上课的

public class two {
    new Timer(1000, taskPerformer).start();
}

因为你不能用方法编写可执行语句，所以应该从任何方法调用，而不是从类中调用，这样你只需声明或定义你的对象/变量。此语句创建新对象，但它将调用无效语句的 start() 方法尝试从构造函数或任何其他方法等任何方法调用

于 2011-12-13T06:44:35.277 回答