java - 我的角色不会在屏幕上移动

Question

我正在编写一个星际飞船游戏，我的角色不会移动，我使用 MouseMotionListener 让角色移动，但我根本无法移动它。这是代码。

主类:

import javax.swing.ImageIcon;
   import javax.swing.JFrame;
    import javax.swing.WindowConstants;
    @SuppressWarnings("serial")
    public class Galactic extends JFrame implements GalacticConstants1 {
    private ImageIcon windowicon=new ImageIcon(getClass().getResource("galactic          ship.jpg"));
    Galactic(){
        galacticComponents();
    }
    private void galacticComponents() {
    setIconImage(windowicon.getImage());
        panel();
        }
        private void panel(){
        GalacticPanel g1=new GalacticPanel();
        add(g1);

        GalacticEngine1 ge=new GalacticEngine1();
        addMouseMotionListener(ge);
        addKeyListener(ge);
    }
        public static void main(String[] args) {
        Galactic g=new Galactic();
        //Initializing game
        g.setSize(d);
        //setting the game size
        g.setTitle("Galactic Ship");
        //setting the game title
        g.setVisible(true);
        //the visibility 
        g.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        //what to do when the close button is pressed
        g.setResizable(false);
        //if the window can be resized
        g.setLocationRelativeTo(null);
        //the location on the screen
    }

}

绘图面板:

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Point;

import javax.swing.ImageIcon;
import javax.swing.JPanel;
@SuppressWarnings("serial")
public class GalacticPanel extends JPanel implements GalacticConstants1{

    public Point point=new Point(Ship_X,Ship_Y);
    Image img;
    ImageIcon i;
    public GalacticPanel() {
        setBackground(Color.black);
    }

    public void paintComponent(Graphics g){
        super.paintComponent(g);

        g.setColor(Color.red);
        //red star color
        g.drawOval(20,40,Star_Width,Star_Height);
        g.fillOval(20,40,Star_Width,Star_Height);
        //first red star
        g.drawOval(200,200,Star_Width,Star_Height);
        g.fillOval(200,200,Star_Width,Star_Height);
        //second red star
        g.drawOval(300,400,Star_Width,Star_Height);
        g.fillOval(300,400,Star_Width,Star_Height);
        //third red star
        g.drawOval(400,550,Star_Width,Star_Height);
        g.fillOval(400,550,Star_Width,Star_Height);
        //fourth red star

        g.setColor(Color.black);
        g.drawRect(0, 0, recW, recH);
        //invisible bounds

        i=new ImageIcon(getClass().getResource("galactic ship.jpg"));
        img=i.getImage();
        g.drawImage(img, Ship_X, Ship_Y, Ship_Width, Ship_Height,null);
        //the ship x and y coordinates the ship width and height arcwidth and archeight


    }

}

游戏引擎:

import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;

public class GalacticEngine1 implements  MouseMotionListener,KeyListener,GalacticConstants1 {
    public int ShipX=Ship_X;
    GalacticPanel g1=new GalacticPanel();

    GalacticEngine1(){
    }

    @Override
    public void mouseDragged(MouseEvent e) {

    }
    @Override
    public void mouseMoved(MouseEvent e) {
        int mouseX=e.getX();

        if(mouseX<ShipX&&ShipX<recW){
            ShipX-=Ship_Movement;
        }else if(mouseX>ShipX){
            ShipX+=Ship_Movement;
        }
        g1.repaint();
    }

    @Override
    public void keyPressed(KeyEvent e) {
        int key=e.getKeyCode();
        if(key==KeyEvent.VK_ESCAPE){
            System.exit(0);
        }
    }

    @Override
    public void keyReleased(KeyEvent e) {}

    @Override
    public void keyTyped(KeyEvent e) {}

}

这是界面:

import java.awt.Dimension;
public interface GalacticConstants1 {
    int Width=500;
    int Height=740;
    Dimension d=new Dimension(Width,Height);
    //Screen dimension
    int Ship_X=230;
    int Ship_Y=670;
    int Ship_Width=40;
    int Ship_Height=20;
    int Ship_Movement=5;
    //Ship qualities
    int Star_Width=5;
    int Star_Height=5;
    //star qualities
    int recW=490;
    int recH=700;
    //invisible rectangle width and height
}

有人可以帮忙吗，我真的很感激。

Answer 1

你这里有一些错误。首先是行 g.drawImage(img, Ship_X, Ship_Y, Ship_Width, Ship_Height,null); 请注意，您正在尝试在坐标 Ship_X/Ship_Y 处绘制图标。这些是常数值。

GalicateEngine1 中还有另一个问题。您在此类中创建并尝试在鼠标移动监听器中重新绘制的面板变量 g1 与您在主类中创建和显示的银河面板不同。

此外，在 GalicateEngine1 中，您正在更新一个名为 ShipX 的变量，这是您真正想在调用 drawImage 时使用的变量。

这里您需要做的是让引擎知道您创建的面板，并且您需要让面板知道引擎的 x 变量应该是什么。我不认为以下是一个好的面向对象的设计或任何东西，我不得不更改代码来绘制一个矩形而不是你的JPEG(无法加载JPEG)，但它通常会做你正在尝试的事情做我认为的。常数没有改变。此外，您还应该注意其他答案中给出的 RE 结构和风格的建议。

主要

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.WindowConstants;
@SuppressWarnings("serial")
public class Galactic extends JFrame implements GalacticConstants1 {
//    private ImageIcon windowicon=new ImageIcon(getClass().getResource("galactic ship.jpg"));
    private ImageIcon windowicon=new ImageIcon("file:blah","");
    Galactic(){
        galacticComponents();
    }
    private void galacticComponents() {
        setIconImage(windowicon.getImage());
        panel();
    }
    private void panel(){
        GalacticEngine1 ge=new GalacticEngine1();
        GalacticPanel g1=new GalacticPanel();
        ge.setPanel(g1);
        g1.setEngine(ge);
        add(g1);

        g1.addMouseMotionListener(ge);
        g1.addKeyListener(ge);
    }
    public static void main(String[] args) {
        Galactic g=new Galactic();
        //Initializing game
        g.setSize(d);
        //setting the game size
        g.setTitle("Galactic Ship");
        //setting the game title
        g.setVisible(true);
        //the visibility
        g.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        //what to do when the close button is pressed
        g.setResizable(false);
        //if the window can be resized
        g.setLocationRelativeTo(null);
        //the location on the screen
    }

}

面板

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Point;

import javax.swing.ImageIcon;
import javax.swing.JPanel;
@SuppressWarnings("serial")
public class GalacticPanel extends JPanel implements GalacticConstants1{

    public Point point=new Point(Ship_X,Ship_Y);
    Image img;
    ImageIcon i;
    GalacticEngine1 ge;

    public void setEngine(GalacticEngine1 ge) {
        this.ge = ge;
    }
    public GalacticPanel() {

        setBackground(Color.white);
    }

    public void paintComponent(Graphics g){
        super.paintComponent(g);

        System.out.println("Painting");

        g.setColor(Color.blue);
        //red star color
        g.drawOval(20,40,Star_Width,Star_Height);
        g.fillOval(20,40,Star_Width,Star_Height);
        //first red star
        g.drawOval(200,200,Star_Width,Star_Height);
        g.fillOval(200,200,Star_Width,Star_Height);
        //second red star
        g.drawOval(300,400,Star_Width,Star_Height);
        g.fillOval(300,400,Star_Width,Star_Height);
        //third red star
        g.drawOval(400,550,Star_Width,Star_Height);
        g.fillOval(400,550,Star_Width,Star_Height);
        //fourth red star

        g.setColor(Color.black);
        g.drawRect(0, 0, recW, recH);
        //invisible bounds


        g.drawRect(ge.getX(), Ship_Y, 20, 20);
        //the ship x and y coordinates the ship width and height arcwidth and archeight


    }

}

引擎

import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;

public class GalacticEngine1 implements  MouseMotionListener,KeyListener,GalacticConstants1 {
    public int ShipX=Ship_X;
    GalacticPanel p;


    public int getX() {return ShipX;}


    public void setPanel(GalacticPanel p)  {
        this.p = p;
    }

    GalacticEngine1(){
    }

    public void mouseDragged(MouseEvent e) {

    }
    public void mouseMoved(MouseEvent e) {
        int mouseX=e.getX();

        if(mouseX<ShipX&&ShipX<recW){
            ShipX-=Ship_Movement;
        }else if(mouseX>ShipX){
            ShipX+=Ship_Movement;
        }

        p.repaint();

    }

    public void keyPressed(KeyEvent e) {
        int key=e.getKeyCode();
        if(key==KeyEvent.VK_ESCAPE){
            System.exit(0);
        }
    }

    public void keyReleased(KeyEvent e) {}

    public void keyTyped(KeyEvent e) {}

}