我正在制作一个需要显示图像的程序。我正在使用 ImageIcon 和 Image 类来执行此操作。我在构造函数中声明了 ImageIcon,然后通过 i.getImage() 分配图像值。除了图像之外的所有内容似乎都加载良好。这是我的代码:
更新:我的图像与代码位于同一目录中。我使用的是 Mac,并且尝试过“image.png”、“./image.png”、“Users/myStuff/Documents/workspace/Game/src/image.png”。这些都没有奏效。
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
@SuppressWarnings("serial")
public class Game extends JFrame {
int x = 100, y = 100;
private Image dbimage;
private Graphics dbg;
Image image;
class AL extends KeyAdapter {
public void keyPressed(KeyEvent e) {
int keyCode = e.getKeyCode();
if (keyCode == e.VK_LEFT) {
if (x <= 20) {
x = 20;
} else {
x -= 5;
}
} else if (keyCode == e.VK_RIGHT) {
if (x >= 230) {
x = 230;
} else {
x += 5;
}
} else if (keyCode == e.VK_UP) {
if (y <= 20) {
y = 20;
} else {
y -= 5;
}
} else if (keyCode == e.VK_DOWN) {
if (y >= 230) {
y = 230;
} else {
y += 5;
}
}
}
}
public Game() {
//load up image
ImageIcon i = new ImageIcon("image.png");
image = i.getImage();
//set up properties
addKeyListener(new AL());
setTitle("Game");
setSize(250, 250);
setResizable(false);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBackground(Color.CYAN);
setVisible(true);
}
public void paint(Graphics g) {
dbimage = createImage(getWidth(), getHeight());
dbg = dbimage.getGraphics();
paintComponent(dbg);
g.drawImage(dbimage, 0, 0, this);
}
public void paintComponent(Graphics g) {
g.setFont(new Font("Arial", Font.BOLD | Font.ITALIC, 30));
g.setColor(Color.MAGENTA);
g.drawString("Hello World!", 50, 50);
g.setColor(Color.RED);
g.drawImage(image, 100, 100, this);
repaint();
}
public static void main(String[] args) {
new Game();
}
}
最佳答案
上面的代码存在重大问题...
首先,如果您的图像与类文件一起存在,那么不要将其作为文件获取,而是将其作为资源获取,如 MadProg 所示(并且本网站上的大多数类似问题都会告诉您):
// get your image as a resource
URL resource = Game.class.getResource(RESOURCE_PATH);
BufferedImage img = null;
try {
// read in using ImageIO
img = ImageIO.read(resource);
} catch (IOException e) {
e.printStackTrace();
System.exit(-1);
}
接下来,永远不要直接在 JFrame 中绘制,当然也不要在其 Paint 方法中绘制。相反,请查看 Swing 绘图教程并遵循他们的指导:在 JPanel 的 PaintComponent 方法中进行绘制,但只有在调用 super 的 PaintComponent 方法之后,以便绘制可以沿着绘制链继续进行。:
// draw within the paintComponent method, not the paint method
@Override
protected void paintComponent(Graphics g) {
// call the super's method to all painting to chain down the line
super.paintComponent(g);
if (dbimage != null) {
g.drawImage(dbimage, imgX, imgY, this);
}
}
在修复 GUI 的大小时,我更喜欢覆盖 JPanel 的 getPreferredSize,例如:
// set the preferred size of the main Game JPanel safely
@Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
把所有的东西放在一起,像这样可能工作:
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.*;
public class Game extends JPanel {
public static final String RESOURCE_PATH = "image.png";
private static final int PREF_W = 400;
private static final int PREF_H = PREF_W;
private BufferedImage dbimage = null;
private int imgX = 0;
private int imgY = 0;
public Game(BufferedImage dbimage) {
this.dbimage = dbimage;
}
// draw within the paintComponent method, not the paint method
@Override
protected void paintComponent(Graphics g) {
// call the super's method to all painting to chain down the line
super.paintComponent(g);
if (dbimage != null) {
g.drawImage(dbimage, imgX, imgY, this);
}
}
// set the preferred size of the main Game JPanel safely
@Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
private static void createAndShowGui() {
// get your image as a resource
URL resource = Game.class.getResource(RESOURCE_PATH);
BufferedImage img = null;
try {
// read in using ImageIO
img = ImageIO.read(resource);
} catch (IOException e) {
e.printStackTrace();
System.exit(-1);
}
// pass image into your Game JPanel
Game mainPanel = new Game(img);
// pass the JPanel into a JFrame
JFrame frame = new JFrame("Game");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true); // and display it
}
public static void main(String[] args) {
// start your Swing GUI in a thread-safe manner
SwingUtilities.invokeLater(() -> {
createAndShowGui();
});
}
}
接下来查找键绑定(bind)以帮助您使用此 GUI 通过击键制作动画
关于Java:图像不显示,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/35005525/