java - 当我在计时器上调用 isRunning() 方法时，图像不会显示

Question

这是我第一次来这个论坛。我的 java 计时器有问题。我的程序在不同时间显示图像。这是我的代码

//TIMER
    //creo timer per il tempo di visualizzazione di ogni singola immagine
    timerDisplay = new Timer(this.timeOfImage * MILLE, this);
    timerDisplay.setRepeats(false);
    timerDisplay.setActionCommand("blackScreen");

    //timer tra le immagini
    timerBetweenImages = new Timer(this.timeBetwImage * MILLE,this);
    timerBetweenImages.setRepeats(false);
    timerBetweenImages.setActionCommand("image");
    //timer prima della scelta
    timerBeforeChoice = new Timer(this.timeBeforeChoice * MILLE,this);
    timerBeforeChoice.setRepeats(false);
    timerBeforeChoice.setActionCommand("Choice");
    //tempo di scelta
    timerChoice = new Timer(this.timeOfChoice * MILLE,this);
    timerChoice.setRepeats(false);
    timerChoice.setActionCommand("End");


   public void actionPerformed(ActionEvent e) {
    // tempo tra immagini consecutive
    if (e.getActionCommand().equals("blackScreen")) {

        label.setIcon(null);
        if (index != numOfImages) {
        timerBetweenImages.start();



        } else {

            label.setIcon(null);
            timerBeforeChoice.start();
        }
    //to see the images
    } else if (index < numOfImages && e.getActionCommand().equals("image")){ 

        label.setIcon(image[index]);

        index++;
        //visualizza

        timerDisplay.start();

        state();

    } else if (e.getActionCommand().equals("Choice")) {

        contentPane.remove(label);
        //modifico il layout per inserire tanti pannelli quanto sono le immagini
        contentPane.setLayout(new GridLayout(1, this.numOfImages));
        repaint();
        validate();
        //creo tanti pannelli quante sono le immagini da visualizzare



           //creo pannello
           JPanel panel1 = new JPanel();
           panel1.setBackground(Color.BLACK);
           panel1.setLayout(new GridLayout(2,1));
           //aggiungo immagine e checkbox al pannello
           JLabel lblNewLabel_1 = new JLabel("");
           lblNewLabel_1.setBackground(Color.BLACK);
           lblNewLabel_1.setHorizontalAlignment(SwingConstants.CENTER);
           lblNewLabel_1.setIcon(image[i]);
           panel1.add(lblNewLabel_1);
           i++;
           chckbxNewCheckBox = new JCheckBox("Immagine " + 1);
           chckbxNewCheckBox.setBackground(Color.BLACK);
           chckbxNewCheckBox.setForeground(Color.WHITE);
           chckbxNewCheckBox.setHorizontalAlignment(SwingConstants.CENTER);
           chckbxNewCheckBox.setFont(new Font("Tahoma", Font.BOLD, 14));
           panel1.add(chckbxNewCheckBox);
          contentPane.add(panel1);  
        //creo pannello
           JPanel panel2 = new JPanel();
           panel2.setBackground(Color.BLACK);
           panel2.setLayout(new GridLayout(2,1));
           //aggiungo immagine e checkbox al pannello
           JLabel lblNewLabel_2 = new JLabel("");
           lblNewLabel_2.setBackground(Color.BLACK);
           lblNewLabel_2.setHorizontalAlignment(SwingConstants.CENTER);
           lblNewLabel_2.setIcon(image[i]);
           panel2.add(lblNewLabel_2);
           i++;
           chckbxNewCheckBox2 = new JCheckBox("Immagine " + 2);
           chckbxNewCheckBox2.setBackground(Color.BLACK);
           chckbxNewCheckBox2.setForeground(Color.WHITE);
           chckbxNewCheckBox2.setHorizontalAlignment(SwingConstants.CENTER);
           chckbxNewCheckBox2.setFont(new Font("Tahoma", Font.BOLD, 14));
           panel2.add(chckbxNewCheckBox2);
           //i++;
           //aggiungo pannello al contentPane
          contentPane.add(panel2);  
           repaint();
           validate();
            chckbxNewCheckBox2.addItemListener(this);
         chckbxNewCheckBox.addItemListener(this);
         state();

     } else if (e.getActionCommand().equals("End")) {

         contentPane.removeAll();
         repaint();
         validate();
         index = this.numOfImages;
         //System.out.println(index);
         this.numOfImages = this.numOfImages + number;
         //System.out.println(numOfImages);
         contentPane.setLayout(new GridLayout(1, 1));
         contentPane.add(label);
         if (numOfImages <= image.length) {
             timerDisplay.start();
         } else {
             //CHIUDI CONNESSIONE
             Edk.INSTANCE.EE_EmoStateFree(eState);
             Edk.INSTANCE.EE_EmoEngineEventFree(eEvent);
             Edk.INSTANCE.EE_EngineDisconnect();
             dispose();
         }

     } 

然后我有这个方法:

public void state(){
    while(timerDisplay.isRunning()){

    state = Edk.INSTANCE.EE_EngineGetNextEvent(eEvent);
    // New event needs to be handled

    if (state == EdkErrorCode.EDK_OK.ToInt()) {

        int eventType = Edk.INSTANCE.EE_EmoEngineEventGetType(eEvent);
        Edk.INSTANCE.EE_EmoEngineEventGetUserId(eEvent, userID);

        // Log the EmoState if it has been updated
        if (eventType == Edk.EE_Event_t.EE_EmoStateUpdated.ToInt()) {

            Edk.INSTANCE.EE_EmoEngineEventGetEmoState(eEvent, eState);
            //tempo
            float timestamp = EmoState.INSTANCE.ES_GetTimeFromStart(eState);
            //user ID
            int user =  userID.getValue();

            //valori emotional
            float shortExcitement = EmoState.INSTANCE.ES_AffectivGetExcitementShortTermScore(eState);
            float longExcitement = EmoState.INSTANCE.ES_AffectivGetExcitementLongTermScore(eState);
            float egagement = EmoState.INSTANCE.ES_AffectivGetEngagementBoredomScore(eState);
            float frustation = EmoState.INSTANCE.ES_AffectivGetFrustrationScore(eState);
            float meditation = EmoState.INSTANCE.ES_AffectivGetMeditationScore(eState);
            if(option == 1){
                output.println(timestamp + ";" + user + ";" + shortExcitement + ";"  +
                         longExcitement + ";" + egagement + ";" + frustation + ";" + meditation + ";");
            } else if (option == 2){
                output.println(timestamp + ";" + user + ";" + shortExcitement + ";"  +
                         longExcitement + ";" + egagement + ";" + frustation + ";" + meditation + ";");
            }


        }

    }
    else if (state != EdkErrorCode.EDK_NO_EVENT.ToInt()) {
        output.println("Internal error in Emotiv Engine!");
        //messaggio di errore
        String message2 = "Internal error in Emotiv Engine!";
           JOptionPane.showMessageDialog(new JFrame(), message2, "Dialog",
           JOptionPane.ERROR_MESSAGE);
    }
    }
}

问题出在我的 state() 方法中，当我调用 timerDisplay.isRunning() 时，程序无法显示图像。事实上，我希望 state() 运行直到 timerDisplay 完成。抱歉我的英语不好......:)

Answer 1

您的 state 方法似乎阻止了事件调度线程。这可以防止处理任何事件(包括绘制和计时器事件)，从而使您的应用程序看起来好像已停止。

出现这种情况是因为 Swing 是单线程环境。这意味着与 UI 的所有交互都必须在事件调度线程的上下文中执行。这也意味着您应该在另一个线程上执行所有阻塞或耗时的处理。

看看SwingWorker 。这将允许您在后台线程中处理“状态”事件，而且还具有易于使用的方法来重新同步 UI/EDT 的任何更新。

还请通读Concurrency in Swing了解更多信息