java - 小程序不显示图像

Question

我正在关注本教程 here

我下载了它的源代码并运行，但图像没有显示。

这是结果

我本来以为结果是这样的 与教程中的结果相同。

代码如下: 启动类.java

package kiloboltgame;

import java.applet.Applet;
import java.awt.Color;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.net.URL;

public class StartingClass extends Applet implements Runnable, KeyListener {

    private Robot robot;
    private Image image, character;
    private Graphics second;
    private URL base;

    @Override
    public void init() {

        setSize(800, 480);
        setBackground(Color.BLACK);
        setFocusable(true);
        addKeyListener(this);
        Frame frame = (Frame) this.getParent().getParent();
        frame.setTitle("Q-Bot Alpha");
        try {
            base = getDocumentBase();

        } catch (Exception e) {
            // TODO: handle exception
            System.out.println(e.toString());
        }

        // Image Setups
        character = getImage(base, "data/character.png");
        System.out.println(" "+base);

    }

    @Override
    public void start() {
        robot = new Robot();

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

    @Override
    public void stop() {
        // TODO Auto-generated method stub
    }

    @Override
    public void destroy() {
        // TODO Auto-generated method stub
    }

    @Override
    public void run() {
        while (true) {
            robot.update();
            repaint();
            try {
                Thread.sleep(17);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

    @Override
    public void update(Graphics g) {
        if (image == null) {
            image = createImage(this.getWidth(), this.getHeight());
            second = image.getGraphics();
        }

        second.setColor(getBackground());
        second.fillRect(0, 0, getWidth(), getHeight());
        second.setColor(getForeground());
        paint(second);

        g.drawImage(image, 0, 0, this);

    }

    @Override
    public void paint(Graphics g) {
        g.drawImage(character, robot.getCenterX() - 61, robot.getCenterY() - 63, this);

    }

    @Override
    public void keyPressed(KeyEvent e) {

        switch (e.getKeyCode()) {
        case KeyEvent.VK_UP:
            System.out.println("Move up");
            break;

        case KeyEvent.VK_DOWN:
            System.out.println("Move down");
            break;

        case KeyEvent.VK_LEFT:
            robot.moveLeft();
            break;

        case KeyEvent.VK_RIGHT:
            robot.moveRight();
            break;

        case KeyEvent.VK_SPACE:
            System.out.println("Jump");
            robot.jump();
            break;

        }

    }

    @Override
    public void keyReleased(KeyEvent e) {
        switch (e.getKeyCode()) {
        case KeyEvent.VK_UP:
            System.out.println("Stop moving up");
            break;

        case KeyEvent.VK_DOWN:
            System.out.println("Stop moving down");
            break;

        case KeyEvent.VK_LEFT:
            robot.stop();
            break;

        case KeyEvent.VK_RIGHT:
            robot.stop();
            break;

        case KeyEvent.VK_SPACE:
            System.out.println("Stop jumping");
            break;
        }

    }

    @Override
    public void keyTyped(KeyEvent e) {
        // TODO Auto-generated method stub
    }
}

机器人.java

package kiloboltgame;

import java.awt.Graphics;

public class Robot {

    private int centerX = 100;
    private int centerY = 382;
    private boolean jumped = false;

    private int speedX = 0;
    private int speedY = 1;


    public void update() {

        // Moves Character or Scrolls Background accordingly.
        if (speedX < 0) {
            centerX += speedX;
        } else if (speedX == 0) {
            //System.out.println("Do not scroll the background.");

        } else {
            if (centerX <= 150) {
                centerX += speedX;
            } else {
                //System.out.println("Scroll Background Here");
            }
        }

        // Updates Y Position
        centerY += speedY;
        if (centerY + speedY >= 382) {
            centerY = 382;
        }

        // Handles Jumping
        if (jumped == true) {
            speedY += 1;

            if (centerY + speedY >= 382) {
                centerY = 382;
                speedY = 0;
                jumped = false;
            }

        }

        // Prevents going beyond X coordinate of 0
        if (centerX + speedX <= 60) {
            centerX = 61;
        }
    }

    public void moveRight() {
        speedX = 6;
    }

    public void moveLeft() {
        speedX = -6;
    }

    public void stop() {
        speedX = 0;
    }

    public void jump() {
        if (jumped == false) {
            speedY = -15;
            jumped = true;
        }

    }

    public int getCenterX() {
        return centerX;
    }

    public int getCenterY() {
        return centerY;
    }

    public boolean isJumped() {
        return jumped;
    }

    public int getSpeedX() {
        return speedX;
    }

    public int getSpeedY() {
        return speedY;
    }

    public void setCenterX(int centerX) {
        this.centerX = centerX;
    }

    public void setCenterY(int centerY) {
        this.centerY = centerY;
    }

    public void setJumped(boolean jumped) {
        this.jumped = jumped;
    }

    public void setSpeedX(int speedX) {
        this.speedX = speedX;
    }

    public void setSpeedY(int speedY) {
        this.speedY = speedY;
    }

}

这是我在 intelij 中的文件结构

代码有什么问题吗？我尝试了“../data/character.png”和“../src/data/character.png”，但它不起作用。

Answer 1

• applet.html 加载小程序的页面。
• 数据(目录)
  • 角色.png

如果这是服务器的结构，则图像将通过以下方式提供:

getImage(base, "data/character.png");

我在上面强调了服务器，因为这显然不是您的 IDE 的设置方式。

<小时/>

Can you elaborate more?

您打开了 src/kilobolt 路径来显示源文件的位置，但是如果您展开 bin 文件夹并向下追踪，您可能会发现bin/kilobolt 目录中的 .class 文件。

IDE 通常不会使用 HTML 文件来加载小程序，但如果 IntelliJ 这样做，它可能会将其放在 bin 目录中，以便它可以直接访问类文件。 从那里到图像的路径将为 ../data/character.png，但建议您不要使用该路径，而是让 IDE 将图像复制到 bin >.

在这个阶段，它已经成为关于 IntelliJ 的问题，因此您有任何进一步的问题，都需要与 IDE 及其使用的运行时类路径有关。