小编Dav*_*wen的帖子

我正在尝试修改此程序,以便绘制城堡的图像,并且我可以使用向上和向下箭头键缩放此图像.我无法让keylistener工作,程序运行但它没有响应按键.任何帮助将不胜感激,谢谢.

import java.awt.*;
import java.awt.geom.*;
import java.util.*;
import javax.swing.*;
import java.net.*;
import java.awt.event.*;

public class DrawImage extends JFrame implements KeyListener {
int scale = 1;
    private Image image;
    enter code here
    public static void main(String[] args) {
        new DrawImage();
    }

    public DrawImage() {
        super("DrawImage");
        setSize(600,600);
        setVisible(true);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        Toolkit tk = Toolkit.getDefaultToolkit();
        image = tk.getImage(getURL("castle.png"));
        addKeyListener(this);
    }

    private URL getURL(String filename) {
        URL url = null;
        try {
            url = this.getClass().getResource(filename);
        }
        catch (Exception e) { }
        return url;
    }

    public …