我正在尝试制作两个以不同速率闪烁的闪烁圆圈。我在 Circle 类中使用 ScheduledExecutorService 来调节闪烁,其持续时间由每个 Circle 中的 ms(毫秒)变量设置。
当我单独制作一辆车时,它们以正确的速率闪烁(我将黑色的设置为 1000 毫秒,红色的设置为 10 毫秒)。但是,当我创建它们并将它们添加到我的 JLayeredPane 时,它们都会在较短的时间内闪烁。
我不太熟悉 ScheduledExecutorService 的使用,因此如果有人可以帮助我解决问题,我将不胜感激!
import java.awt.Color;
import java.awt.Graphics;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import java.awt.*;
import javax.swing.*;
public class blinker extends JFrame
{
JLayeredPane lp = new JLayeredPane();
public carlight()
{
lp.setLayout(new BorderLayout());
lp.setPreferredSize(new Dimension(450, 450));
car c1 = new car(new Color(0, 0, 0), "1", 10, 0, 0);
c1.setOpaque(false);
car c2 = new car(new Color(255, 0, 0), "2", 1000, 100, 100);
c2.setOpaque(false);
c1.setBounds(0, 0, 450, 450);
c2.setBounds(0, 0, 450, 450);
lp.add(c2);
lp.add(c1);
add(lp);
setTitle("Carlights");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(500, 500);
setVisible(true);
}
public static void main(String[] args)
{
carlight cl = new carlight();
}
}
class Circle extends JPanel
{
private Color color;
private String name;
private long ms;
private int x, y;
private boolean on = true;
ScheduledExecutorService service = Executors.newSingleThreadScheduledExecutor();
@Override
public void paintComponent(Graphics g)
{
super.paintComponents(g);
if(on)
{
g.setColor(color);
int r = 50;
g.fillOval(x, y, r, r);
on = false;
}
else
{
on = true;
}
}
public car(Color c, String s, long l, int x, int y)
{
color = c;
name = s;
ms = l;
this.x = x;
this.y = y;
this.service.scheduleAtFixedRate(new Runnable()
{
public void run()
{
repaint();
}
}, 0, ms, TimeUnit.MILLISECONDS);
}
}
最佳答案
您的问题是您在 PaintComponent 方法中具有程序逻辑,您可以在其中更改 boolean 变量的状态。您无法完全控制何时或是否调用此方法,事实上,当调用 repaint 时,将调用 bothpaintComponents,这就是您的信号灯不起作用的原因。解决方案:通过在其他地方更改 boolean 字段 on 的状态,从 PaintComponent 方法中获取逻辑。此外,您还需要使用 Swing 计时器来实现更好的 Swing 线程。
您还需要修复布局的使用,包括避免使用 setBounds。在您的设置中,将其与 BorderLayout 一起使用时,这尤其危险且不可预测。就我个人而言,我不会让 Circle 类扩展 JPanel,而是使其成为一个逻辑类,而不是组件类,然后我将拥有绘图组件,一个扩展 JPanel 的类,保存 Circle 类的实例,然后在其 PaintComponent 中绘制它们。例如:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;
import javax.swing.*;
@SuppressWarnings("serial")
public class BlinkerEg extends JPanel {
private static final int PREF_W = 450;
private static final int PREF_H = PREF_W;
private List<Circle> circles = new ArrayList<>();
public BlinkerEg() {
circles.add(new Circle(Color.red, 1000, 0, 0, 450, this));
circles.add(new Circle(Color.black, 60, 0, 0, 450, this));
}
@Override
public Dimension getPreferredSize() {
return new Dimension(PREF_W, PREF_H);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
for (Circle circle : circles) {
circle.paint(g2);
}
}
private static void createAndShowGui() {
BlinkerEg mainPanel = new BlinkerEg();
JFrame frame = new JFrame("BlinkerEg");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
class Circle {
private Color color;
private int x, y;
private int diam;
private JComponent component;
private boolean on = true;
public Circle(Color color, int ms, int x, int y, int diam, JComponent component) {
this.color = color;
this.x = x;
this.y = y;
this.diam = diam;
this.component = component;
new Timer(ms, new TimerListener()).start();
}
public void paint(Graphics g) {
if (on) {
g.setColor(color);
g.fillOval(x, y, diam, diam);
}
}
public boolean isOn() {
return on;
}
public void setOn(boolean on) {
this.on = on;
}
private class TimerListener implements ActionListener {
@Override
public void actionPerformed(ActionEvent e) {
setOn(!isOn());
component.repaint();
}
}
}
关于java - 两个 ScheduledExecutorService 互相覆盖?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/26568614/