java - 未创建用于显示拉绳文本的屏幕

Question

我正在研究 Buckysroom.org 上提供的 Java 游戏开发教程。我正在创建一个 Screen 类，它允许我全屏显示。然后，当我尝试用文本绘制它时，屏幕不会出现，并且只有文本显示在我的工作窗口(Eclipse)上如果我注释掉paint方法或将其设为paintComponent，则会出现红色屏幕，但没有任何内容文本。谁能帮我解决这个问题？

屏幕类:

import java.awt.*;
import javax.swing.JFrame;

public class Screen {

private GraphicsDevice vc;

public Screen() {
    GraphicsEnvironment env = GraphicsEnvironment.getLocalGraphicsEnvironment();
    vc = env.getDefaultScreenDevice();
}

public void setFullScreen(DisplayMode dm, JFrame window) {
    window.setUndecorated(true);
    window.setResizable(false);
    vc.setFullScreenWindow(window);
    if (dm != null && vc.isDisplayChangeSupported()) {
        try {
            vc.setDisplayMode(dm);
        } catch (Exception ex) {
        }
    }
}

public Window getFullScreenWindow() {
    return vc.getFullScreenWindow();
}

public void restoreScreen() {
    Window w = vc.getFullScreenWindow();
    if (w != null) {
        w.dispose();
    }
    vc.setFullScreenWindow(null);
 }
}

这是我称之为的类:

import java.awt.*;
import javax.swing.JFrame;

public class bucky extends JFrame {

public static void main(String[] args) {
    DisplayMode dm = new DisplayMode(800, 600, 16, DisplayMode.REFRESH_RATE_UNKNOWN);
    bucky m = new bucky();
    m.run(dm);
}

public void run(DisplayMode dm) {
    this.getContentPane().setBackground(Color.RED);
    setForeground(Color.BLACK);
    setFont(new Font("Arial", Font.PLAIN, 24));
    Screen s = new Screen();
    try {
        s.setFullScreen(dm, this);
        try {
            Thread.sleep(5000);
        } catch (Exception ex) {
        }
    } finally {
        s.restoreScreen();
    }    
}

public void paint(Graphics g) {

    g.drawString("This is awesome", 200, 200);
 }
}

Answer 1

我怀疑 Thread.sleep 会导致事件调度线程进入休眠状态，从而阻止它处理任何绘制事件(或与此相关的任何其他类型的事件)和/或者 JFrame 的 paint 方法不是执行绘制的合适方法(通常出于多种原因)...

相反，您应该考虑使用像 javax.swing.Timer 这样的东西，您可以用它来设置 future 某个时间的闹钟，它会给您回电。

您还应该考虑使用诸如 JPanel 之类的东西来执行自定义绘画，例如......

import java.awt.Color;
import java.awt.Dimension;
import java.awt.DisplayMode;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
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 javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class FullScreenTest {

    public static void main(String[] args) {
        new FullScreenTest();
    }

    public FullScreenTest() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setContentPane(new TestPane());

                DisplayMode dm = new DisplayMode(800, 600, 16, DisplayMode.REFRESH_RATE_UNKNOWN);
                Screen.setFullScreen(null, frame);

                Timer timer = new Timer(5000, new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent e) {
                        Screen.restoreScreen();
                    }
                });
                timer.start();
            }
        });
    }

    public class TestPane extends JPanel {

        public TestPane() {
            setFont(new Font("Arial", Font.PLAIN, 24));
            setBackground(Color.RED);
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(200, 200);
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2d = (Graphics2D) g.create();
            g.drawString("This is awesome", 200, 200);
            g2d.dispose();
        }

    }

    public static class Screen {

        public static GraphicsDevice getGraphicsDevice() {
            GraphicsEnvironment env = GraphicsEnvironment.getLocalGraphicsEnvironment();
            return env.getDefaultScreenDevice();
        }

        public static void setFullScreen(DisplayMode dm, JFrame window) {
            window.setUndecorated(true);
            window.setResizable(false);
            GraphicsDevice gd = getGraphicsDevice();
            gd.setFullScreenWindow(window);
            if (dm != null && gd.isDisplayChangeSupported()) {
                try {
                    gd.setDisplayMode(dm);
                } catch (Exception ex) {
                }
            }
        }

        public static Window getFullScreenWindow() {
            GraphicsDevice gd = getGraphicsDevice();
            return gd.getFullScreenWindow();
        }

        public static void restoreScreen() {
            GraphicsDevice gd = getGraphicsDevice();
            Window w = gd.getFullScreenWindow();
            if (w != null) {
                w.dispose();
            }
            gd.setFullScreenWindow(null);
        }
    }

}

看一下:

• Concurrency in Swing
• How to Use Swing Timers
• Performing Custom Painting

了解更多详情...

此外，由于它所执行的工作类型，Screen 也可以是一个完全静态 类。它不维护上下文信息，只是提供实用功能 - 恕我直言。

如果每个 GraphicsDevice 都需要一个，那将是另一回事了；)