Question

如何平稳移动JPanel并更新JLabel？

我想在JFrame上显示当前时间，所以我创建了一个新的java.util.Timer并每秒更新一次标签。

我还创建了另一个Java线程来移动面板组件。

但是在移动面板并在框架上显示（更新）时间时，面板会刷新以形成原始位置。

所以我在Google中搜索该问题，但找不到解决方法。

//Code to move jPanel smoothly
        Thread t = new Thread(){
            int i = 0 ;
            public void run(){
                while(i<150){
                    i++;
                    jPanel2.setLocation(i, jPanel2.getY());
                    try {
                        Thread.sleep(100);
                    } catch (InterruptedException ex) {
                    }
                }
            }
        };
        t.start();

// Code to show Time
       Timer t = new javax.swing.Timer(1, new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                jLabel1.setText(new Date()+"");
            }
        });
        t.start();

Answer 1

这是一个小示例，说明如何为组件提供动画和更新。

import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.time.LocalTime;
import java.time.format.DateTimeFormatter;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
import javax.swing.WindowConstants;

/**
 * <code>MovedClock</code>.
 */
public class MovedClock {

    private final JLabel clock = new JLabel();
    private final DateTimeFormatter format = DateTimeFormatter.ofPattern("HH:mm:ss");

    private void startUI() {
        JFrame frame = new JFrame("Moved clock");
        frame.setLayout(null); // usually it's a bad idea, but for animation we need this.
        clock.setBounds(0, 50, 50, 20);
        frame.add(clock);
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.setSize(500, 200);
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
        updateClock();
        Timer clockTimer = new Timer(1000, e -> updateClock());
        clockTimer.start();
        // 15 milliseconds for about 60fps
        Timer moveTimer = new Timer(15, new ActionListener() {

            private int count = 1;

            private int increment = 1;

            @Override
            public void actionPerformed(ActionEvent e) {
                if (count == 435 || count == 0) {
                    increment = -increment;
                }
                Point loc = clock.getLocation();
                loc.x += increment;
                clock.setLocation(loc);
                count += increment;
            }
        });
        moveTimer.start();
    }

    private void updateClock() {
        clock.setText(LocalTime.now().format(format));
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new MovedClock()::startUI);
    }
}

JPanel的平滑运动并同时更新JLabel

1 个答案: