[英]Image wont draw in Java
因此,我尝试将图像绘制到JFrame上,并使用defualt工具包作为图像观察器,但是每次运行项目时,它都不会绘制图像,但是它将绘制并成功移动(成功)其他形状我测试。
private class Painter extends JPanel implements ImageObserver {
@Override
public void paintComponent(Graphics g){
super.paintComponent(g);
Toolkit tk = Toolkit.getDefaultToolkit();
Image player = tk.createImage("player.jpg");
tk.prepareImage(player, 50, 50, rootPane);
g.setColor(Color.red);
// g.drawRect(x, y, 50, 50);
g.drawImage(player, 200, 200, this);
window.repaint();
}
}
您的paintComponent方法应该什么也不做。
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.red);
// g.drawRect(x, y, 50, 50);
g.drawImage(player, 200, 200, this);
}
工具箱和图像行需要位于Painter构造函数中。 类名应以大写字母开头。
根据评论进行编辑:
您编写的代码如下所示:
private Image player;
public Painter() throws Exception {
player = ImageIO.read(getClass().getResource("player.jpg"));
}
player.jpg必须与源代码位于同一目录中。 否则,您的图像目录必须位于Java应用程序的类路径中。
这是一个完整,简单的Swing应用程序,用于在JPanel上绘制图像。
package com.ggl.testing;
import java.awt.Graphics;
import java.awt.Image;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class MyPanel extends JPanel {
private static final long serialVersionUID = -9008812738915944216L;
private static JFrame frame;
private static MyPanel panel;
private static Image image;
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
image = getImage();
frame = new JFrame();
panel = new MyPanel();
frame.setSize(500, 500);
frame.add(panel);
frame.setVisible(true);
}
});
}
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(image, 100, 100, MyPanel.this);
}
private static Image getImage() {
Image image = null;
try {
image = ImageIO.read(MyPanel.class.getResource("maze.jpg"));
} catch (IOException e) {
e.printStackTrace();
}
return image;
}
}
将maze.jpg更改为您的图像,然后将该图像放置在与此示例代码相同的目录中。
使用ImageIO将图像读取到类的构造函数中的类的变量中,以便在需要绘制图像时可以使用该图像。 如果找不到图像,ImageIO将生成一条消息。
对于任何感兴趣的人,最终的代码都是这样的。 之前未包含动作侦听器,因为它与问题几乎无关。 之所以包含最后一个摘要(公共绘画),是因为无法从静态main方法内部调用动作侦听器。 该子类最初包含所有window。*行,但会导致无限数量的已创建窗口,因此在将其移到主窗口时,新的绘画调用必须封装在一个受控循环中,并且位于main方法的外部。 特别感谢所有为我提供帮助的人,尤其是吉尔伯特·勒布朗
package painting;
import javax.swing.*;
import java.awt.*;
import java.awt.event.KeyEvent;
import java.awt.event.*;
import java.io.*;
import javax.imageio.ImageIO;
/**
*
* @author tt700
*/
public class Painting extends JPanel {
// declaring variables that control movement, show the frame, and make the picture
int x =50, y =50, counter = 0;
private static JFrame window = new JFrame("Paint a Picture");
private static Painting canvas;
private static Image player;
// main method
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable(){
@Override
public void run(){
JLabel title = new JLabel("Making a picture frame");
window.add(title, BorderLayout.NORTH);
canvas = new Painting();
window.add(canvas);
player = getImage("player.jpg");
window.setVisible(true);
window.setSize(300,300);
window.setForeground(Color.red);
}
});
}
@Override
// the method that does all the painting
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(player, x, y, Painting.this);
}
// the method that gets a desired image and makes it displayable, with arguments it can be used to swap pictures easily
private static Image getImage(String imagePath){
Image player = null;
try{
player = ImageIO.read(Painting.class.getResource(imagePath));
}catch(IOException e){
e.printStackTrace();
}
return player;
}
// the class that controls movement of the picture
public class movement implements KeyListener{
@Override
public void keyTyped(KeyEvent e) {
throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}
@Override
// the method that listens to which keys are pressed and acts accordingly
public void keyPressed(KeyEvent e) {
if(e.getKeyCode() == KeyEvent.VK_RIGHT){
x += 5;
window.repaint();
}
else if(e.getKeyCode() == KeyEvent.VK_LEFT){
x -= 5;
window.repaint();
}
else if(e.getKeyCode() == KeyEvent.VK_UP){
y -= 5;
window.repaint();
}
else if(e.getKeyCode() == KeyEvent.VK_DOWN){
y += 5;
window.repaint();
}
}
@Override
public void keyReleased(KeyEvent e) {
throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}
}
// the subclass that adds a key listener to the proper component, created since action listeners can't be called in static methods (main)
public Painting(){
do{
counter = 1;
window.addKeyListener(new movement());
}while(counter < 1);
}
}
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