所以这个问题的答案可能是完全显而易见的,但我就是看不到。为什么我的 Graphics 对象没有显示我告诉它的内容?我相当确定我尊重 Swing 并发性等,但也许不是。这是我的 JPanel 代码:
package com.kraken.towerdefense.graphics;
import com.kraken.towerdefense.TowerDefense;
import com.kraken.towerdefense.listener.KeyHandler;
import com.kraken.towerdefense.listener.MouseMotionHandler;
import com.kraken.towerdefense.scene.Scene;
import javax.swing.*;
import java.awt.*;
import java.awt.geom.RoundRectangle2D;
public class Screen extends JPanel implements Runnable {
Thread thread = new Thread(this);
private int FPS = 0;
public Scene scene;
TowerDefense tD;
private boolean running = false;
public RoundRectangle2D.Float playGame, quitGame;
public boolean playGameHighlighted, quitGameHighlighted;
@Override
public void run() {
long lastFrame = System.currentTimeMillis();
int frames = 0;
running = true;
while (running) {
repaint();
frames++;
if (System.currentTimeMillis() - 1000 >= lastFrame) {
FPS = frames;
frames = 0;
lastFrame = System.currentTimeMillis();
}
}
System.exit(0);
}
public Screen(TowerDefense tD) {
thread.start();
addKeyListener(new KeyHandler(this));
addMouseMotionListener(new MouseMotionHandler(this));
this.tD = tD;
scene = Scene.MENU;
}
@Override
public void paintComponent(Graphics g2) {
super.paintComponent(g2);
playGame = new RoundRectangle2D.Float((getWidth() / 2) - 200, (getHeight() / 2) - 100, 400, 100, 10, 10);
quitGame = new RoundRectangle2D.Float((getWidth() / 2) - 200, (getHeight() / 2) + 20, 400, 100, 10, 10);
Graphics2D g = (Graphics2D) g2.create();
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g.clearRect(0, 0, getWidth(), getHeight());
g.drawString("FPS: " + FPS, 10, 10);
if (scene == Scene.MENU) {
if (playGameHighlighted) {
g.setColor(new Color(255, 152, 56));
} else {
g.setColor(new Color(4, 47, 61));
}
g.fill(playGame);
if (quitGameHighlighted) {
g.setColor(new Color(255, 152, 56));
} else {
g.setColor(new Color(4, 47, 61));
}
g.fill(quitGame);
g.setColor(Color.WHITE);
g.setFont(new Font("Gisha", Font.PLAIN, 20));
g.drawString("Play", (getWidth() / 2) - (g.getFontMetrics().stringWidth("Play") / 2), (getHeight() / 2) - 45);
g.drawString("Quit", (getWidth() / 2) - (g.getFontMetrics().stringWidth("Quit") / 2), (getHeight() / 2) + 75);
}
}
public class KeyTyped {
public void keyESC() {
running = false;
}
}
}
这是我的场景枚举:
package com.kraken.towerdefense.scene;
public enum Scene {
MENU,
GAME
}
我很确定我不需要提供 JFrame 代码,但如果有必要我会提供。您可以针对我的代码中的问题提供任何其他解决方案,我们将不胜感激。谢谢!
编辑 1
这是我的 MouseMotionListener 类:
package com.kraken.towerdefense.listener;
import com.kraken.towerdefense.graphics.Screen;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
public class MouseMotionHandler implements MouseMotionListener {
Screen screen;
public MouseMotionHandler(Screen screen) {
this.screen = screen;
}
@Override
public void mouseDragged(MouseEvent e) {
}
@Override
public void mouseMoved(MouseEvent e) {
if (screen.playGame.contains(e.getPoint())) {
screen.playGameHighlighted = true;
} else {
screen.playGameHighlighted = false;
}
if (screen.quitGame.contains(e.getPoint())) {
screen.quitGameHighlighted = true;
} else {
screen.playGameHighlighted = false;
}
}
}
这是我的 JFrame 代码:
package com.kraken.towerdefense;
import com.kraken.towerdefense.graphics.Screen;
import javax.swing.*;
public class TowerDefense extends JFrame {
public static void main(String[] args) {
new TowerDefense();
}
public TowerDefense() {
setExtendedState(MAXIMIZED_BOTH);
setUndecorated(true);
setTitle("Tower Defense");
setDefaultCloseOperation(EXIT_ON_CLOSE);
setResizable(false);
Screen screen = new Screen(this);
this.add(screen);
setVisible(true);
}
}
这是我的 KeyListener 代码:
package com.kraken.towerdefense.listener;
import com.kraken.towerdefense.graphics.Screen;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
public class KeyHandler implements KeyListener {
private Screen screen;
private Screen.KeyTyped keyTyped;
public KeyHandler(Screen screen) {
this.screen = screen;
keyTyped = screen.new KeyTyped();
}
@Override
public void keyTyped(KeyEvent e) {
}
@Override
public void keyPressed(KeyEvent e) {
if (e.getKeyCode() == 27) {
keyTyped.keyESC();
}
}
@Override
public void keyReleased(KeyEvent e) {
}
}
以上就是我的全部类(class),希望对您有所帮助
最佳答案
所以,我删除了你的代码以使其运行并能够显示...
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class GraphicsTest {
public static void main(String[] args) {
new GraphicsTest();
}
public GraphicsTest() {
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.add(new Screen());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public enum Scene {
MENU,
GAME
}
public class Screen extends JPanel implements Runnable {
Thread thread = new Thread(this);
private int FPS = 0;
public Scene scene;
private boolean running = false;
@Override
public void run() {
long lastFrame = System.currentTimeMillis();
int frames = 0;
running = true;
scene = Scene.MENU;
while (running) {
repaint();
frames++;
if (System.currentTimeMillis() - 1000 >= lastFrame) {
FPS = frames;
frames = 0;
lastFrame = System.currentTimeMillis();
}
}
System.exit(0);
}
public Screen() {
thread.start();
}
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.clearRect(0, 0, getWidth(), getHeight());
g.drawString("FPS: " + FPS, 10, 10);
if (scene == Scene.MENU) {
g.setColor(Color.BLACK);
g.fillRoundRect((getWidth() / 2) - 100, (getHeight() / 2) - 50, 200, 100, 25, 25);
}
}
}
}
这表明您所描述的问题是在其他地方。
对我来说这个;
g.clearRect(0, 0, tD.getWidth(), tD.getHeight());
看起来很可疑,因为当您应该依赖组件自己的宽度/高度属性时,您却依赖于 TowerDefense
属性(除了 clearRect
实际上不需要在此背景下)。
这进一步让我怀疑您实际上并未将 Screen
组件添加到任何可显示的内容
另一个可能的问题是您正在使用适当的布局管理器,但由于您的 Screen
类不提供任何 preferredSize
提示,这将是一个您未展示的其他问题
根据对原始问题的更改进行更新
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import static java.awt.Frame.MAXIMIZED_BOTH;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.RoundRectangle2D;
import javafx.scene.Scene;
import javax.swing.JFrame;
import static javax.swing.JFrame.EXIT_ON_CLOSE;
import javax.swing.JPanel;
public class TowerDefense extends JFrame {
public static void main(String[] args) {
new TowerDefense();
}
public TowerDefense() {
// setExtendedState(MAXIMIZED_BOTH);
// setUndecorated(true);
setTitle("Tower Defense");
setDefaultCloseOperation(EXIT_ON_CLOSE);
// setResizable(false);
Screen screen = new Screen(this);
this.add(screen);
pack();
setVisible(true);
}
public enum Scene {
MENU,
GAME
}
public class Screen extends JPanel implements Runnable {
Thread thread = new Thread(this);
private int FPS = 0;
public Scene scene;
TowerDefense tD;
private boolean running = false;
public RoundRectangle2D.Float playGame, quitGame;
public boolean playGameHighlighted, quitGameHighlighted;
@Override
public void run() {
// long lastFrame = System.currentTimeMillis();
// int frames = 0;
//
// running = true;
//
// while (running) {
// repaint();
//
// frames++;
//
// if (System.currentTimeMillis() - 1000 >= lastFrame) {
// FPS = frames;
// frames = 0;
//
// lastFrame = System.currentTimeMillis();
// }
// }
//
// System.exit(0);
}
@Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
public Screen(TowerDefense tD) {
thread.start();
addKeyListener(new KeyHandler(this));
addMouseMotionListener(
new MouseAdapter() {
@Override
public void mouseMoved(MouseEvent e) {
playGameHighlighted = playGame.contains(e.getPoint());
quitGameHighlighted = quitGame.contains(e.getPoint());
repaint();
}
});
this.tD = tD;
scene = Scene.MENU;
}
@Override
public void paintComponent(Graphics g2) {
super.paintComponent(g2);
playGame = new RoundRectangle2D.Float((getWidth() / 2) - 200, (getHeight() / 2) - 100, 400, 100, 10, 10);
quitGame = new RoundRectangle2D.Float((getWidth() / 2) - 200, (getHeight() / 2) + 20, 400, 100, 10, 10);
Graphics2D g = (Graphics2D) g2.create();
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g.clearRect(0, 0, getWidth(), getHeight());
g.drawString("FPS: " + FPS, 10, 10);
if (scene == Scene.MENU) {
if (playGameHighlighted) {
g.setColor(new Color(255, 152, 56));
} else {
g.setColor(new Color(4, 47, 61));
}
g.draw(playGame);
if (quitGameHighlighted) {
g.setColor(new Color(255, 152, 56));
} else {
g.setColor(new Color(4, 47, 61));
}
g.draw(quitGame);
g.setColor(Color.WHITE);
g.setFont(new Font("Gisha", Font.PLAIN, 20));
g.drawString("Play", (getWidth() / 2) - (g.getFontMetrics().stringWidth("Play") / 2), (getHeight() / 2) - 45);
g.drawString("Quit", (getWidth() / 2) - (g.getFontMetrics().stringWidth("Quit") / 2), (getHeight() / 2) + 75);
}
}
public class KeyTyped {
public void keyESC() {
running = false;
}
}
}
public class KeyHandler implements KeyListener {
private Screen screen;
private Screen.KeyTyped keyTyped;
public KeyHandler(Screen screen) {
this.screen = screen;
keyTyped = screen.new KeyTyped();
}
@Override
public void keyTyped(KeyEvent e) {
}
@Override
public void keyPressed(KeyEvent e) {
if (e.getKeyCode() == 27) {
keyTyped.keyESC();
}
}
@Override
public void keyReleased(KeyEvent e) {
}
}
}
关于java - 图形对象未显示在屏幕上,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/33965663/