Question

我有JFrame和一些标签，当我按下按钮时，我想逐个显示这些标签（但延迟时间）。我尝试使用此代码：

        label_1.setVisible(1000);
        Thread.sleep(time);
        label_2.setVisible(1000);
        Thread.sleep(time);
        label_3.setVisible(1000);
        Thread.sleep(time);
        label_4.setVisible(1000);

但应用程序会等待一段时间（4000毫秒），然后立即显示所有标签。

Answer 1

这是使用swing计时器类的代码，它执行延迟以显示帧上的标签。您只需创建一个ActionListener对象，其中包含您想要延迟执行的代码以及基本条件< / strong>用于停止计时器。然后创建一个像new Timer(Delay,ActionListenerObject)

这样的计时器对象
import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.*; public class LabelDelay { JFrame frame; JLabel label1; JLabel label2; JLabel label3; JLabel label4; JPanel contentPane; Timer timer; int count=0; public LabelDelay() { JFrame.setDefaultLookAndFeelDecorated(true); frame = new JFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); contentPane = new JPanel(new GridLayout(1,4)); label1 = new JLabel("Label1"); contentPane.add(label1); label2 = new JLabel("Label2"); contentPane.add(label2); label3 = new JLabel("Label3"); contentPane.add(label3); label4 = new JLabel("Label4"); contentPane.add(label4); frame.setContentPane(contentPane); frame.pack(); label1.setVisible(false); label2.setVisible(false); label3.setVisible(false); label4.setVisible(false); ActionListener action = new ActionListener() { @Override public void actionPerformed(ActionEvent e) { switch(count) { case 0: label1.setVisible(true); break; case 1: label2.setVisible(true); break; case 2: label3.setVisible(true); break; case 3: label4.setVisible(true); break; case 4: timer.stop();//base criteria break; } count++; } }; frame.setVisible(true); timer = new Timer(1000, action); timer.start(); } public static void main(String args[]) { new LabelDelay(); } }

Answer 2

睡眠UI线程冻结GUI，但程序在后台运行本身最终会给你结果睡眠。相反，您可以使用Executors来实现此目的。否则，您需要使用.join()方法创建单独的线程以等待先前的线程完成。

https://docs.oracle.com/javase/tutorial/essential/concurrency/join.html

Thread t1 = new Thread(() -> {label_1.setVisible(true); Thread.sleep(1000);});
Thread t2 = new Thread(() -> {label_2.setVisible(true); Thread.sleep(1000);});
Thread t3 = new Thread(() -> {label_3.setVisible(true); Thread.sleep(1000);});
Thread t4 = new Thread(() -> {label_4.setVisible(true); Thread.sleep(1000);});

t1.start();
t2.start();
t2.join();
t3.start();
t3.join();
t4.start();
t4.join();

此代码示例假设您使用的是Java 8

<强>更新

不管上面的例子，你可以使用下面的链接很好地理解Swing并发。

https://docs.oracle.com/javase/tutorial/uiswing/concurrency/index.html

Answer 3

此外，您可以简单地使用一个接一个地开始的四个Timer对象

Timer timer4 = new Timer(500, e -> {
    label_4.setVisible(true);
});

Timer timer3 = new Timer(500, e -> {
    label_3.setVisible(true);
    timer4.start();
});

Timer timer2 = new Timer(500, e -> {
    label_2.setVisible(true);
    timer3.start();
});

Timer timer1 = new Timer(500, e -> {
    label_1.setVisible(true);
    timer2.start();
});
timer1.start();

Answer 4

试试这个：

public class TestFrame extends JFrame {

    private JLabel labels[] = {
            new JLabel("Label 1"),
            new JLabel("Label 2"),
            new JLabel("Label 3"),
            new JLabel("Label 4")
    };

    private SwingWorker<Void, Integer> worker = new SwingWorker<Void, Integer>() {
        @Override
        protected Void doInBackground() throws Exception {
            for(int i = 0; i < labels.length; i++) {
                TimeUnit.MILLISECONDS.sleep(4000);
                publish(i);
            }

            return null;
        }

        @Override
        protected void process(List<Integer> chunks) {
            chunks.stream().forEach(i -> labels[i].setVisible(true));
        }
    };

    public TestFrame() throws HeadlessException {
        super("Test Frame");
        createGUI();
    }

    private void createGUI() {
        setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        setMinimumSize(new Dimension(300, 100));

        JPanel panel = new JPanel();
        panel.setLayout(new BoxLayout(panel, BoxLayout.PAGE_AXIS));

        Arrays.stream(labels).forEach(label -> {
            label.setVisible(false);
            panel.add(label);
        });

        add(panel, BorderLayout.CENTER);

        pack();
        setLocationRelativeTo(null);

        addWindowListener(new WindowAdapter() {
            @Override
            public void windowOpened(WindowEvent e) {
                worker.execute();
            }
        });
    }
}

如何在Swing GUI中延迟？

4 个答案: