如何在Java中刷新窗口类的图形

我试图画一个vlcj（VLC库的java绑定）面板，这样我就可以播放视频并在上面画。我遇到了一些问题。以下是完整的基本代码：

代码清单1:AppOverlay.java

package app;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.HeadlessException;
import java.awt.Window;
import java.awt.image.BufferedImage;
import java.io.IOException;

import javax.imageio.ImageIO;

import com.sun.jna.platform.WindowUtils;

@SuppressWarnings("serial")
public class AppOverlay extends Window implements Runnable {

    private final boolean isRunning;
    private final int fps;
    private BufferedImage graphics;
    private BufferedImage img;
    private int x, y;
    private boolean ltr;

    public AppOverlay(Window owner) {
        super(owner, WindowUtils.getAlphaCompatibleGraphicsConfiguration());
        setBackground(new Color(0,0,0,0));

        graphics    = new BufferedImage(1280,800, BufferedImage.TYPE_INT_ARGB);
        isRunning   = true;
        img         = null;
        ltr         = true;
        fps         = 60;
        x           = 0;
        y           = 0;
    }

    @Override
    public void run(){
        while(isRunning){

            try{
                Thread.sleep(1000/fps);
            } catch(InterruptedException e){
                e.printStackTrace();
            }

            if(ltr) {
                if(x < 1280) x++;
                else ltr = false;
            } else {
                if(x < 0) ltr = true;
                else x--;
            }

            repaint();
        }
    }

    public void createAndShowGUI() {
        setVisible(true);

        Thread thread = new Thread(this);
        thread.start();

        String path = "Drive:\\path\\to\\image.png";
        try {
            img = ImageIO.read(new java.io.FileInputStream(path));
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

    @Override
    public void paint(Graphics g) {
        Graphics2D g2d = (Graphics2D)g;
        Graphics2D gfx = graphics.createGraphics();
        gfx.setColor(new Color(255,255,255,0));
        gfx.clearRect(0, 0, 1280, 800);
        if(img != null) gfx.drawImage(img, x, y, null);
        gfx.dispose();
        g2d.drawImage(graphics, 0, 0, null);
    }
}

package app;

import uk.co.caprica.vlcj.player.component.EmbeddedMediaPlayerComponent;

@SuppressWarnings("serial")
public class AppPlayer extends EmbeddedMediaPlayerComponent {

}

package app;

import java.awt.Dimension;

import javax.swing.JFrame;

@SuppressWarnings("serial")
public class AppFrame extends JFrame {

    private AppPlayer appPlayer;
    private AppOverlay overlay;

    public AppFrame(){
        super();
    }

    public void createAndShowGUI() {

        appPlayer = new AppPlayer();
        appPlayer.setPreferredSize(new Dimension(1280,800));
        getContentPane().add(appPlayer);

        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setTitle("App");
        setVisible(true);
        pack();

        overlay = new AppOverlay(this);
        appPlayer.mediaPlayer().overlay().set(overlay);
        appPlayer.mediaPlayer().overlay().enable(true);
        overlay.createAndShowGUI();
    }
}

package main;

import javax.swing.SwingUtilities;

import app.AppFrame;

public class Main {

    public static void main(String[] args) {
        final AppFrame app = new AppFrame();
        SwingUtilities.invokeLater( new Runnable() {
            @Override
            public void run() {
                app.createAndShowGUI();
            }
        });
    }

}

package app;

import java.awt.Color;
import java.awt.Graphics;

import javax.swing.JPanel;

public class AppPanel extends JPanel implements Runnable {
    private int x, y;
    private boolean ltr;

    public AppPanel() {
        x   = 0;
        y   = 0;
        ltr = true;
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        g.setColor(new Color(0,0,0,0));
        g.clearRect(0, 0, 1280, 800);
        g.setColor(Color.RED);
        g.fillRect(x, y, 100, 100);
    }

    @Override
    public void run() {
        while(true){

            try{
                Thread.sleep(1000/60);
            } catch(InterruptedException e){
                e.printStackTrace();
            }
            if(ltr) {
                if(x < 1280) x++;
                else ltr = false;
            } else {
                if(x < 0) ltr = true;
                else x--;
            }

            repaint();
        }
    }
}

代码清单3:AppFrame.java

package app;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.HeadlessException;
import java.awt.Window;
import java.awt.image.BufferedImage;
import java.io.IOException;

import javax.imageio.ImageIO;

import com.sun.jna.platform.WindowUtils;

@SuppressWarnings("serial")
public class AppOverlay extends Window implements Runnable {

    private final boolean isRunning;
    private final int fps;
    private BufferedImage graphics;
    private BufferedImage img;
    private int x, y;
    private boolean ltr;

    public AppOverlay(Window owner) {
        super(owner, WindowUtils.getAlphaCompatibleGraphicsConfiguration());
        setBackground(new Color(0,0,0,0));

        graphics    = new BufferedImage(1280,800, BufferedImage.TYPE_INT_ARGB);
        isRunning   = true;
        img         = null;
        ltr         = true;
        fps         = 60;
        x           = 0;
        y           = 0;
    }

    @Override
    public void run(){
        while(isRunning){

            try{
                Thread.sleep(1000/fps);
            } catch(InterruptedException e){
                e.printStackTrace();
            }

            if(ltr) {
                if(x < 1280) x++;
                else ltr = false;
            } else {
                if(x < 0) ltr = true;
                else x--;
            }

            repaint();
        }
    }

    public void createAndShowGUI() {
        setVisible(true);

        Thread thread = new Thread(this);
        thread.start();

        String path = "Drive:\\path\\to\\image.png";
        try {
            img = ImageIO.read(new java.io.FileInputStream(path));
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

    @Override
    public void paint(Graphics g) {
        Graphics2D g2d = (Graphics2D)g;
        Graphics2D gfx = graphics.createGraphics();
        gfx.setColor(new Color(255,255,255,0));
        gfx.clearRect(0, 0, 1280, 800);
        if(img != null) gfx.drawImage(img, x, y, null);
        gfx.dispose();
        g2d.drawImage(graphics, 0, 0, null);
    }
}

package app;

import uk.co.caprica.vlcj.player.component.EmbeddedMediaPlayerComponent;

@SuppressWarnings("serial")
public class AppPlayer extends EmbeddedMediaPlayerComponent {

}

package app;

import java.awt.Dimension;

import javax.swing.JFrame;

@SuppressWarnings("serial")
public class AppFrame extends JFrame {

    private AppPlayer appPlayer;
    private AppOverlay overlay;

    public AppFrame(){
        super();
    }

    public void createAndShowGUI() {

        appPlayer = new AppPlayer();
        appPlayer.setPreferredSize(new Dimension(1280,800));
        getContentPane().add(appPlayer);

        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setTitle("App");
        setVisible(true);
        pack();

        overlay = new AppOverlay(this);
        appPlayer.mediaPlayer().overlay().set(overlay);
        appPlayer.mediaPlayer().overlay().enable(true);
        overlay.createAndShowGUI();
    }
}

package main;

import javax.swing.SwingUtilities;

import app.AppFrame;

public class Main {

    public static void main(String[] args) {
        final AppFrame app = new AppFrame();
        SwingUtilities.invokeLater( new Runnable() {
            @Override
            public void run() {
                app.createAndShowGUI();
            }
        });
    }

}

package app;

import java.awt.Color;
import java.awt.Graphics;

import javax.swing.JPanel;

public class AppPanel extends JPanel implements Runnable {
    private int x, y;
    private boolean ltr;

    public AppPanel() {
        x   = 0;
        y   = 0;
        ltr = true;
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        g.setColor(new Color(0,0,0,0));
        g.clearRect(0, 0, 1280, 800);
        g.setColor(Color.RED);
        g.fillRect(x, y, 100, 100);
    }

    @Override
    public void run() {
        while(true){

            try{
                Thread.sleep(1000/60);
            } catch(InterruptedException e){
                e.printStackTrace();
            }
            if(ltr) {
                if(x < 1280) x++;
                else ltr = false;
            } else {
                if(x < 0) ltr = true;
                else x--;
            }

            repaint();
        }
    }
}

代码清单4:Main.java

package app;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.HeadlessException;
import java.awt.Window;
import java.awt.image.BufferedImage;
import java.io.IOException;

import javax.imageio.ImageIO;

import com.sun.jna.platform.WindowUtils;

@SuppressWarnings("serial")
public class AppOverlay extends Window implements Runnable {

    private final boolean isRunning;
    private final int fps;
    private BufferedImage graphics;
    private BufferedImage img;
    private int x, y;
    private boolean ltr;

    public AppOverlay(Window owner) {
        super(owner, WindowUtils.getAlphaCompatibleGraphicsConfiguration());
        setBackground(new Color(0,0,0,0));

        graphics    = new BufferedImage(1280,800, BufferedImage.TYPE_INT_ARGB);
        isRunning   = true;
        img         = null;
        ltr         = true;
        fps         = 60;
        x           = 0;
        y           = 0;
    }

    @Override
    public void run(){
        while(isRunning){

            try{
                Thread.sleep(1000/fps);
            } catch(InterruptedException e){
                e.printStackTrace();
            }

            if(ltr) {
                if(x < 1280) x++;
                else ltr = false;
            } else {
                if(x < 0) ltr = true;
                else x--;
            }

            repaint();
        }
    }

    public void createAndShowGUI() {
        setVisible(true);

        Thread thread = new Thread(this);
        thread.start();

        String path = "Drive:\\path\\to\\image.png";
        try {
            img = ImageIO.read(new java.io.FileInputStream(path));
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

    @Override
    public void paint(Graphics g) {
        Graphics2D g2d = (Graphics2D)g;
        Graphics2D gfx = graphics.createGraphics();
        gfx.setColor(new Color(255,255,255,0));
        gfx.clearRect(0, 0, 1280, 800);
        if(img != null) gfx.drawImage(img, x, y, null);
        gfx.dispose();
        g2d.drawImage(graphics, 0, 0, null);
    }
}

package app;

import uk.co.caprica.vlcj.player.component.EmbeddedMediaPlayerComponent;

@SuppressWarnings("serial")
public class AppPlayer extends EmbeddedMediaPlayerComponent {

}

package app;

import java.awt.Dimension;

import javax.swing.JFrame;

@SuppressWarnings("serial")
public class AppFrame extends JFrame {

    private AppPlayer appPlayer;
    private AppOverlay overlay;

    public AppFrame(){
        super();
    }

    public void createAndShowGUI() {

        appPlayer = new AppPlayer();
        appPlayer.setPreferredSize(new Dimension(1280,800));
        getContentPane().add(appPlayer);

        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setTitle("App");
        setVisible(true);
        pack();

        overlay = new AppOverlay(this);
        appPlayer.mediaPlayer().overlay().set(overlay);
        appPlayer.mediaPlayer().overlay().enable(true);
        overlay.createAndShowGUI();
    }
}

package main;

import javax.swing.SwingUtilities;

import app.AppFrame;

public class Main {

    public static void main(String[] args) {
        final AppFrame app = new AppFrame();
        SwingUtilities.invokeLater( new Runnable() {
            @Override
            public void run() {
                app.createAndShowGUI();
            }
        });
    }

}

package app;

import java.awt.Color;
import java.awt.Graphics;

import javax.swing.JPanel;

public class AppPanel extends JPanel implements Runnable {
    private int x, y;
    private boolean ltr;

    public AppPanel() {
        x   = 0;
        y   = 0;
        ltr = true;
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        g.setColor(new Color(0,0,0,0));
        g.clearRect(0, 0, 1280, 800);
        g.setColor(Color.RED);
        g.fillRect(x, y, 100, 100);
    }

    @Override
    public void run() {
        while(true){

            try{
                Thread.sleep(1000/60);
            } catch(InterruptedException e){
                e.printStackTrace();
            }
            if(ltr) {
                if(x < 1280) x++;
                else ltr = false;
            } else {
                if(x < 0) ltr = true;
                else x--;
            }

            repaint();
        }
    }
}

有了它和vlcj-4库，你应该可以自己测试我的代码了。我的问题是覆盖（扩展窗口类的AppOverlay类）不会显示或刷新动画，除非我取消选择窗口（单击其他窗口或桌面或操作系统工具栏），使窗口（应用程序）处于非活动状态，然后再次选择窗口（应用程序）。它将只加载一个帧，仅此而已。我必须取消选择并再次选择窗口以加载另一帧（这仅适用于叠加，即如果我在AppPlayer类中播放视频，视频将正常播放）

我想要的是能够在覆盖上绘制一些动画图形。我知道JPanel类有paintComponent（）方法，但Window类没有该方法（只有paint（）和repaint（）方法可用）

我该怎么做才能解决这个问题

编辑：

我尝试添加一个我在上面绘制的JPanel，而不是直接在AppOverlay上绘制

代码清单5:AppPanel.java

package app;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.HeadlessException;
import java.awt.Window;
import java.awt.image.BufferedImage;
import java.io.IOException;

import javax.imageio.ImageIO;

import com.sun.jna.platform.WindowUtils;

@SuppressWarnings("serial")
public class AppOverlay extends Window implements Runnable {

    private final boolean isRunning;
    private final int fps;
    private BufferedImage graphics;
    private BufferedImage img;
    private int x, y;
    private boolean ltr;

    public AppOverlay(Window owner) {
        super(owner, WindowUtils.getAlphaCompatibleGraphicsConfiguration());
        setBackground(new Color(0,0,0,0));

        graphics    = new BufferedImage(1280,800, BufferedImage.TYPE_INT_ARGB);
        isRunning   = true;
        img         = null;
        ltr         = true;
        fps         = 60;
        x           = 0;
        y           = 0;
    }

    @Override
    public void run(){
        while(isRunning){

            try{
                Thread.sleep(1000/fps);
            } catch(InterruptedException e){
                e.printStackTrace();
            }

            if(ltr) {
                if(x < 1280) x++;
                else ltr = false;
            } else {
                if(x < 0) ltr = true;
                else x--;
            }

            repaint();
        }
    }

    public void createAndShowGUI() {
        setVisible(true);

        Thread thread = new Thread(this);
        thread.start();

        String path = "Drive:\\path\\to\\image.png";
        try {
            img = ImageIO.read(new java.io.FileInputStream(path));
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

    @Override
    public void paint(Graphics g) {
        Graphics2D g2d = (Graphics2D)g;
        Graphics2D gfx = graphics.createGraphics();
        gfx.setColor(new Color(255,255,255,0));
        gfx.clearRect(0, 0, 1280, 800);
        if(img != null) gfx.drawImage(img, x, y, null);
        gfx.dispose();
        g2d.drawImage(graphics, 0, 0, null);
    }
}

package app;

import uk.co.caprica.vlcj.player.component.EmbeddedMediaPlayerComponent;

@SuppressWarnings("serial")
public class AppPlayer extends EmbeddedMediaPlayerComponent {

}

package app;

import java.awt.Dimension;

import javax.swing.JFrame;

@SuppressWarnings("serial")
public class AppFrame extends JFrame {

    private AppPlayer appPlayer;
    private AppOverlay overlay;

    public AppFrame(){
        super();
    }

    public void createAndShowGUI() {

        appPlayer = new AppPlayer();
        appPlayer.setPreferredSize(new Dimension(1280,800));
        getContentPane().add(appPlayer);

        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setTitle("App");
        setVisible(true);
        pack();

        overlay = new AppOverlay(this);
        appPlayer.mediaPlayer().overlay().set(overlay);
        appPlayer.mediaPlayer().overlay().enable(true);
        overlay.createAndShowGUI();
    }
}

package main;

import javax.swing.SwingUtilities;

import app.AppFrame;

public class Main {

    public static void main(String[] args) {
        final AppFrame app = new AppFrame();
        SwingUtilities.invokeLater( new Runnable() {
            @Override
            public void run() {
                app.createAndShowGUI();
            }
        });
    }

}

package app;

import java.awt.Color;
import java.awt.Graphics;

import javax.swing.JPanel;

public class AppPanel extends JPanel implements Runnable {
    private int x, y;
    private boolean ltr;

    public AppPanel() {
        x   = 0;
        y   = 0;
        ltr = true;
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        g.setColor(new Color(0,0,0,0));
        g.clearRect(0, 0, 1280, 800);
        g.setColor(Color.RED);
        g.fillRect(x, y, 100, 100);
    }

    @Override
    public void run() {
        while(true){

            try{
                Thread.sleep(1000/60);
            } catch(InterruptedException e){
                e.printStackTrace();
            }
            if(ltr) {
                if(x < 1280) x++;
                else ltr = false;
            } else {
                if(x < 0) ltr = true;
                else x--;
            }

            repaint();
        }
    }
}

这样做将显示JPanel的图形，并根据需要设置动画

---

如果您知道如何使JPanel背景透明（以便我们可以看穿它），同时仍让它显示其图形。这肯定会解决问题。

您已经完成了大部分工作。只需调用

app.repaint（）在每次绘制帧时重新绘制帧即可；

您可以使用JComponent中的以下方法：（）

---

我仔细研究了一下你的例子，想出了一些有效的方法，但我不认为这是一个好的解决方案

主要的问题似乎是没有办法告诉覆盖层刷新（或者我只是没有找到它）。只是

重新绘制

覆盖层不会在屏幕上更新它，所以我使用的解决方法是隐藏并再次显示它

对于更新间隔的计时，我使用了

javax.swing.Timer

。 （在真实版本中，您可能希望通过

MediaPlayerEventListener

启动和停止计时器）

作为副作用，调用

repaint

方法，并调整

x

坐标以在屏幕上移动图像

在下面的简化示例中（使用

main

运行它），我移动了一个带有x坐标的红色矩形，而不是一些未知图像

导入java.awt.Color；
导入java.awt.Dimension；
导入java.awt.Graphics；
导入java.awt.HeadlessException；
导入java.awt.Window；
导入java.awt.event.ActionEvent；
导入java.awt.event.ActionListener；
导入javax.swing.JFrame；
导入javax.swing.Timer；
导入com.sun.jna.platform.WindowUtils；
导入uk.co.caprica.vlcj.player.component.EmbeddedMediaPlayerComponent；
import uk.co.caprica.vlcj.player.embedded.OverlayApi；
公共类AppFrame扩展了JFrame{
私有静态最终长serialVersionUID=-1569823648323129877L；
公共类覆盖扩展窗口{
私有静态最终长serialVersionUID=8337750467830040964L；
私有整数x，y；
私有布尔ltr=true；
公共覆盖（窗口所有者）抛出HeadlessException{
super（所有者，WindowUtils.getAlphaCompatibleGraphicConfiguration（））；
挫折背景（新颜色（0,0,0,0））；
}
@凌驾
公共空间涂料（图g）{
超级油漆（g）；
如果（ltr）{
if（x<1180）
x+=1；
其他的
ltr=假；
}否则{
if（x<0）
ltr=真；
其他的
x-=1；
}
g、 setColor（Color.RED）；
g、 fillRect（x，y，100100）；
字符串s=整数。toString（x）；
g、 setColor（Color.WHITE）；
g、 拉丝字符（s.toCharArray（），0，s.length（），x+10，y+50）；
}
}
私有嵌入式媒体播放器组件appPlayer；
public void createAndShowGUI（）{
appPlayer=新的EmbeddedMediaPlayerComponent（）；
setPreferredSize（新维度（1280800））；
getContentPane（）.add（appPlayer）；
setDefaultCloseOperation（关闭时退出）；
setTitle（“App”）；
setVisible（真）；
包装（）；
覆盖层=新覆盖层（本）；
OverlayApi api=appPlayer.mediaPlayer（）.overlay（）；
api.set（覆盖）；
api.enable（true）；
//appPlayer.mediaPlayer（）.media（）.play（“…”）；
计时器计时器=新计时器（0，新ActionListener（）{
@凌驾
已执行的公共无效操作（操作事件e）{
api.enable（假）；
api.enable（true）；
}
});
timer.setRepeats（真）；
定时器设置延迟（200）；
timer.start（）；
}
}

---

如果这是您的一个选择，那么使用

动画gif

可能会容易得多。至少它本身可以工作（不需要计时器）

---

更新：

正如您所发现的，使用

JPanel

似乎效果更好。 只需使用

setOpaque（false）

使其透明即可

这里是一个调整后的例子

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.HeadlessException;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;

import uk.co.caprica.vlcj.player.component.EmbeddedMediaPlayerComponent;
import uk.co.caprica.vlcj.player.embedded.OverlayApi;

public class AppFrame2 extends JFrame {

    private static final long serialVersionUID = -1569823648323129877L;

    public class OverlayPanel extends JPanel {

        private static final long serialVersionUID = 8070414617530302145L;

        private int x, y;
        private boolean ltr = true;

        public OverlayPanel() {
            this.setOpaque(false);
        }

        @Override
        public void paint(Graphics g) {

            super.paint(g);

            if (ltr) {
                if (x < 1180)
                    x += 1;
                else
                    ltr = false;
            } else {
                if (x < 0)
                    ltr = true;
                else
                    x -= 1;
            }

            g.setColor(Color.RED);
            g.fillRect(x, y, 100, 100);

            String s = Integer.toString(x);
            g.setColor(Color.WHITE);
            g.drawChars(s.toCharArray(), 0, s.length(), x+10, y+50);
        }
    }

    public class Overlay extends Window {

        private static final long serialVersionUID = 8337750467830040964L;

        OverlayPanel panel;

        public Overlay(Window owner) throws HeadlessException {
            super(owner);
            setBackground(new Color(0,0,0,0));

            panel = new OverlayPanel();
            this.add(panel);
        }
    }

    private EmbeddedMediaPlayerComponent appPlayer;

    public void createAndShowGUI() {

        appPlayer = new EmbeddedMediaPlayerComponent();
        appPlayer.setPreferredSize(new Dimension(1280, 800));
        getContentPane().add(appPlayer);

        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setTitle("App");
        setVisible(true);
        pack();

        Overlay overlay = new Overlay(this);

        OverlayApi api = appPlayer.mediaPlayer().overlay();
        api.set(overlay);
        api.enable(true);

        //appPlayer.mediaPlayer().media().play(" ... ");

        Timer timer = new Timer(0, new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                overlay.panel.repaint();
            }
        });
        timer.setRepeats(true);
        timer.setDelay(17);
        timer.start();
    }
}

导入java.awt.Color；
导入java.awt.Dimension；
导入java.awt.Graphics；
导入java.awt.HeadlessException；
导入java.awt.Window；
导入java.awt.event.ActionEvent；
导入java.awt.event.ActionListener；
导入javax.swing.JFrame；
导入javax.swing.JPanel；
导入javax.swing.Timer；
import uk.co.caprica.vlcj.player.component.Em