java - 为计时器创建 ActionListener

Question

我在声明 ActionListener 和创建新 ActionEvent 的细节方面遇到了麻烦。我的目标是创建一个 java.swing.Timer 来运行一些代码来继续播放幻灯片，我只是在努力正确声明计时器以及与之相关的操作。

public abstract class Actions implements ActionListener{
            public ActionListener TimePANG = new ActionListener(){
                @Override
                public void actionPerformed(ActionEvent evt){

                            waitTime = Integer.valueOf(lblWaitput.getText());

                            if (waitTime <= 0){
                                waitTime = 60;
                            }

                            // METHOD TO CLEAR UP DEBRIS AND TO SPLIT INTO ARRAY
                            temp = txtList.getText();
                            temp = temp.toLowerCase();
                            selects = temp.split(" ");
                            for (i = 0; i < selects.length; i++){ //CLEANS UP VARIABLES FOR A PROPER PATH TO GRAB IMAGES FROM
                                selects[i] = "/SlideShow/" + selects[i] + ".jpg";
                                selectcount++;
                            }     // END OF CLEANING

                            //START OF SLIDE SHOW
                            for (x = 0; x <= selectcount; x++){//THE LOOP THAT CYCLES THROUGH THE IMAGES
                                lblDisplay.setIcon(null);
                                System.out.println(selects[x]); //THE VARIABLE WHICH THE IMAGE IS IN
                                lblDisplay.setIcon(new javax.swing.ImageIcon(getClass().getResource(selects[x]))); //DISPLAYING IMAGE
                            }
                }
            };
        } 

我的完整代码如下。

/*
     * To change this template, choose Tools | Templates
     * and open the template in the editor.
     */
    package SlideShow;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    import javax.swing.Timer;
    /**
     *
     * @author palaceag196
     */
    public class MainSlides extends javax.swing.JFrame{

        String[] options = {"Soccer","Basketball","Football","Hockey","Ravioli","Banana","Pizza","Hotdog","Cat","Dog","Bird","Hamster"};
        String temp;
        String[] selects;
        int selectcount;
        int i, x;
        int waitTime;
        //              new ImageIcon(getClass().getResource(temp))
        /**
         * Creates new form MainSlides
         */

        public MainSlides() {
            initComponents();
        }
        public abstract class Actions implements ActionListener{
            public ActionListener TimePANG = new ActionListener(){
                @Override
                public void actionPerformed(ActionEvent evt){

                            waitTime = Integer.valueOf(lblWaitput.getText());

                            if (waitTime <= 0){
                                waitTime = 60;
                            }

                            // METHOD TO CLEAR UP DEBRIS AND TO SPLIT INTO ARRAY
                            temp = txtList.getText();
                            temp = temp.toLowerCase();
                            selects = temp.split(" ");
                            for (i = 0; i < selects.length; i++){ //CLEANS UP VARIABLES FOR A PROPER PATH TO GRAB IMAGES FROM
                                selects[i] = "/SlideShow/" + selects[i] + ".jpg";
                                selectcount++;
                            }     // END OF CLEANING

                            //START OF SLIDE SHOW
                            for (x = 0; x <= selectcount; x++){//THE LOOP THAT CYCLES THROUGH THE IMAGES
                                lblDisplay.setIcon(null);
                                System.out.println(selects[x]); //THE VARIABLE WHICH THE IMAGE IS IN
                                lblDisplay.setIcon(new javax.swing.ImageIcon(getClass().getResource(selects[x]))); //DISPLAYING IMAGE
                            }
                }
            };
        }          
        /**
         * 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() {

            jScrollPane1 = new javax.swing.JScrollPane();
            listSelect = new javax.swing.JList();
            jScrollPane2 = new javax.swing.JScrollPane();
            txtList = new javax.swing.JTextArea();
            lblWaitput = new javax.swing.JTextField();
            jLabel1 = new javax.swing.JLabel();
            btnStart = new javax.swing.JButton();
            lblDisplay = new javax.swing.JLabel();

            setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

            listSelect.setModel(new javax.swing.AbstractListModel() {
                String[] strings = { "Soccer", "Basketball", "Football", "Hockey", "Ravioli", "Banana", "Pizza", "Hotdog", "Cat", "Dog", "Bird", "Hamster" };
                public int getSize() { return strings.length; }
                public Object getElementAt(int i) { return strings[i]; }
            });
            listSelect.addMouseListener(new java.awt.event.MouseAdapter() {
                public void mouseClicked(java.awt.event.MouseEvent evt) {
                    listSelectMouseClicked(evt);
                }
            });
            jScrollPane1.setViewportView(listSelect);

            txtList.setColumns(12);
            txtList.setFont(new java.awt.Font("Monospaced", 0, 12)); // NOI18N
            txtList.setLineWrap(true);
            txtList.setRows(12);
            txtList.setAutoscrolls(false);
            txtList.setFocusable(false);
            jScrollPane2.setViewportView(txtList);

            lblWaitput.setText("60");
            lblWaitput.setToolTipText("Input wait time here.");

            jLabel1.setText("Wait Time:");

            btnStart.setText("Start The Show");
            btnStart.addActionListener(new java.awt.event.ActionListener() {
                public void actionPerformed(java.awt.event.ActionEvent evt) {
                    btnStartActionPerformed(evt);
                }
            });

            javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
            getContentPane().setLayout(layout);
            layout.setHorizontalGroup(
                layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(layout.createSequentialGroup()
                    .addContainerGap()
                    .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 80, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                    .addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                    .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                        .addGroup(layout.createSequentialGroup()
                            .addComponent(jLabel1)
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                            .addComponent(lblWaitput, javax.swing.GroupLayout.PREFERRED_SIZE, 60, javax.swing.GroupLayout.PREFERRED_SIZE)
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 88, Short.MAX_VALUE)
                            .addComponent(btnStart))
                        .addComponent(lblDisplay, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
                    .addContainerGap())
            );
            layout.setVerticalGroup(
                layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(layout.createSequentialGroup()
                    .addContainerGap()
                    .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                        .addGroup(layout.createSequentialGroup()
                            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                                .addComponent(lblWaitput, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                                .addComponent(jLabel1)
                                .addComponent(btnStart))
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                            .addComponent(lblDisplay, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
                        .addGroup(layout.createSequentialGroup()
                            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                                .addComponent(jScrollPane1)
                                .addComponent(jScrollPane2, javax.swing.GroupLayout.DEFAULT_SIZE, 251, Short.MAX_VALUE))
                            .addGap(0, 0, Short.MAX_VALUE)))
                    .addContainerGap())
            );

            pack();
        }// </editor-fold>                        

        private void listSelectMouseClicked(java.awt.event.MouseEvent evt) {                                        

            txtList.setText(txtList.getText()  + options[listSelect.getSelectedIndex()] + " ");

            // TODO add your handling code here:
        }                                       

        private void btnStartActionPerformed(java.awt.event.ActionEvent evt) {                                         
                    Timer time = new Timer(waitTime, TimePANG);
                    time.start();

            // END OF SLIDES NOTHING FURTHER
        }                                        


        /**
         * @param args the command line arguments
         */
        public static void main(String args[]) {
            /* Set the Nimbus look and feel */
            //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
            /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
             * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
             */
            try {
                for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                    if ("Nimbus".equals(info.getName())) {
                        javax.swing.UIManager.setLookAndFeel(info.getClassName());
                        break;
                    }
                }
            } catch (ClassNotFoundException ex) {
                java.util.logging.Logger.getLogger(MainSlides.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
            } catch (InstantiationException ex) {
                java.util.logging.Logger.getLogger(MainSlides.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
            } catch (IllegalAccessException ex) {
                java.util.logging.Logger.getLogger(MainSlides.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
            } catch (javax.swing.UnsupportedLookAndFeelException ex) {
                java.util.logging.Logger.getLogger(MainSlides.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
            }
            //</editor-fold>

            /* Create and display the form */
            java.awt.EventQueue.invokeLater(new Runnable() {
                public void run() {
                    new MainSlides().setVisible(true);
                }
            });
        }
        // Variables declaration - do not modify                     
        private javax.swing.JButton btnStart;
        private javax.swing.JLabel jLabel1;
        private javax.swing.JScrollPane jScrollPane1;
        private javax.swing.JScrollPane jScrollPane2;
        private javax.swing.JLabel lblDisplay;
        private javax.swing.JTextField lblWaitput;
        private javax.swing.JList listSelect;
        private javax.swing.JTextArea txtList;
        // End of variables declaration                   

    }

Answer 1

使用计时器的目的是消除所有循环。

您有一个对象数组，因此您还需要一个索引来跟踪当前正在显示的对象。

因此，当您单击按钮时，您所做的就是启动计时器，然后 ActionListener 将根据当前索引显示对象。

因此“开始”按钮的 ActionListener 中的代码可能类似于:

ActionListener al = new ActionListener()
{
    @Override
    public void actionPerformed(ActionEvent e)
    {
        String fileName = "..." + selects[selectIndex] + ".jpg";
        Icon icon = new ImageIcon( filename );
        label.setIcon( icon );
        selectIndex++;

        if (selectIndex) > selects.length)
            selectIndex = 0;
    }
};

...

Timer timer = new Timer(waitTime, al);
timer.start();