不重新显示图像

大家好，我在这里有点堆叠。 当我运行程序并按下提交按钮时，它应该每2秒更换4张图片。但是它不会重新显示图像。 如果有人能帮我一把，那就太好了。 我正在使用eclipse，程序正在编译和运行。 这是代码。

/** Here is the GUI of the program * class name SlideShowGui.java * @author Kiril Anastasov * @date 07/03/2012 */ import java.awt.*; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.*; public class SlideShowGui extends JPanel implements ActionListener, Runnable { JLabel name, comments, images; JTextField namejtf, commentsjtf, captionjtf; JButton submit; ImageIcon pictures1, pictures2, pictures3, pictures4; //ImageIcon []pictures2 = {galileo1.jpg}; SlideShowGui() { name = new JLabel("Name:"); this.add(name); namejtf = new JTextField(15); this.add(namejtf); comments = new JLabel("Comments:"); this.add(comments); commentsjtf = new JTextField(15); this.add(commentsjtf); submit = new JButton("Submit"); this.add(submit); submit.addActionListener(this); pictures1 = new ImageIcon("galileo1.jpg"); images = new JLabel(pictures1); this.add(images); pictures2 = new ImageIcon("galileo2.jpg"); this.add(images); pictures3 = new ImageIcon("galileo3.jpg"); this.add(images); pictures4 = new ImageIcon("galileo4.jpg"); this.add(images); captionjtf = new JTextField(24); this.add(captionjtf); //pictures = new ImageIcon("galileo1.jpg"); // images.setIcon(pictures); } public void actionPerformed(ActionEvent ae) { Thread t = new Thread(this); t.start(); if(ae.getSource() == submit) { int i = 0; boolean go = true; while(go) { i++; System.out.println(i); try { Thread.sleep(2000); if(i == 1) { pictures1 = new ImageIcon("galileo1.jpg"); images.setIcon(pictures1); System.out.println("picture 1 should be displayed here"); } if(i == 2) { pictures2 = new ImageIcon("galileo2.jpg"); images.setIcon(pictures2); System.out.println("picture 2 should be displayed here"); } if(i == 3) { pictures3 = new ImageIcon("galileo3.jpg"); images.setIcon(pictures3); System.out.println("picture 3 should be displayed here"); } if(i == 4) { pictures4 = new ImageIcon("galileo4.jpg"); images.setIcon(pictures4); System.out.println("picture 4 should be displayed here"); } if(i == 4) { i = 0; } } catch (InterruptedException ie) { System.out.println("thread exception"); } } } } public void run() { } } 

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 /**The driver class of the program. Here is the JFrame * class name TestSlideShow.java * @author Kiril Anastasov * @date 07/03/2012 */ import java.awt.*; import javax.swing.*; public class TestSlideShow { public static void main(String[] args) { JFrame application = new JFrame(); SlideShowGui panel = new SlideShowGui(); application.add(panel); application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); application.setSize(300,600); application.setLocation(400,100); application.setVisible(true); } } 

Answer 1

始终使用javax.swing.Timer永远不要在Swing atleast中使用Thread.sleep(...) 。 在这里尝试这个代码，但是要替换图像的path ：

 import java.awt.*; import java.awt.event.*; import javax.swing.*; public class SlideShow extends JPanel { private int i = 0; private Timer timer; private JLabel images = new JLabel(); private Icon bg = UIManager.getIcon("OptionPane.warningIcon"); private Icon red = UIManager.getIcon("OptionPane.errorIcon"); private Icon blue = UIManager.getIcon("OptionPane.informationIcon"); private ImageIcon pictures1, pictures2, pictures3, pictures4; private ActionListener action = new ActionListener() { public void actionPerformed(ActionEvent ae) { boolean go = true; i++; System.out.println(i); if(i == 1) { images.setIcon(bg); System.out.println("picture 1 should be displayed here"); } if(i == 2) { images.setIcon(red); System.out.println("picture 2 should be displayed here"); } if(i == 3) { images.setIcon(blue); System.out.println("picture 3 should be displayed here"); } if(i == 4) { images.setIcon(bg); System.out.println("picture 4 should be displayed here"); } if(i == 5) { go = false; timer.stop(); System.exit(0); } revalidate(); repaint(); } }; public SlideShow() { JFrame frame = new JFrame("SLIDE SHOW"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setLocationByPlatform(true); frame.getContentPane().add(this); add(images); frame.setSize(300, 300); frame.setVisible(true); timer = new Timer(2000, action); timer.start(); } public static void main(String... args) { SwingUtilities.invokeLater(new Runnable() { public void run() { new SlideShow(); } }); } } 

Answer 2

整个if (i == ...部分可以简化。在SlideShowGUI声明一个静态类成员：

 private final static ImageIcon[] icons = {new ImageIcon("galileo1.jpg"), new ImageIcon("galileo2.jpg"), new ImageIcon("galileo3.jpg"), new ImageIcon("galileo4.jpg")}; 

并用它来代替if语句：

 images.setIcon(icons[i-1]); System.printf("Picture %s should be displayed%n", i-1); if (i == 4) { i = 0; } 

Answer 3

您可以像Andreas_D提到的那样简化代码。

当你调用Thread.sleep()时，你当前的设计会阻塞主线程，这会冻结你的应用程序。

如果要更新Image ，则应在run()方法中实现更新代码。

因此，如果您检测到用户按下提交JButton ，请创建并启动新的Thread以更新UI。