使用鼠标输入

Question

我正在尝试制作一个游戏，在该游戏中当物体撞击您时您会死亡，但我没有使用 MouseEntered 方法。有人可以告诉我怎么做吗？我还想问一下加载所有精灵图像的问题。我成功加载了它们，但未能使岩石从一个图像变为另一个图像。

测试员class

import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Random;

import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.Timer;



public class Tester extends JPanel{ 

    public JFrame window = new JFrame("Rock stuff");
    public Timer tmr ;
    public ArrayList<Rock> rocks = new ArrayList<Rock>();


    public Tester(){
        window.setBounds(500, 400, 500, 500);
        window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        window.setVisible(true);
        window.add(this);



        tmr = new Timer(1, new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                for(Rock r:rocks)
                    r.move();
                repaint();
            }
        });

        this.addMouseListener(new MouseListener() {

            @Override
            public void mouseReleased(MouseEvent e) { }

            @Override
            public void mousePressed(MouseEvent e) {
                for(Rock r:rocks) {
                    if(r.contains(e.getPoint())){
                        Rock newRock = r.split();
                        if(newRock != null){
                            rocks.add(newRock);
                            rocks.add(newRock);
                        }
                        else{
                            rocks.remove(r);
                            if(rocks.size()==0){
                                tmr.stop();
                                repaint();
                                JOptionPane.showMessageDialog(window, "Game Over");
                            }
                        }
                        return;

                    }
                }
            }

            @Override
            public void mouseExited(MouseEvent e) {
                // TODO Auto-generated method stub

            }

            @Override
            public void mouseEntered(MouseEvent e) {
                for(Rock r:rocks){
                    if(r.contains(e.getPoint())){
                        rocks.clear();
                        JOptionPane.showMessageDialog(window, "Game Over");
                    }
                }

            }

            @Override
            public void mouseClicked(MouseEvent e) {

            }
        });
        addrock(10);


        tmr.start();;
    }


    private void addrock(int count) {
        Random rnd = new Random();
        for(int i=0;i<count;i++)
            rocks.add(new Rock( rnd.nextInt(getWidth()),
                    rnd.nextInt(getHeight()),
                    32,32,
                    (rnd.nextBoolean()?1:-1),
                    (rnd.nextBoolean()?1:-1),
                    true
                    ) );
    }

    public void paint(Graphics g){
        super.paint(g);
        Rock.sw = getWidth();
        Rock.sh = getHeight();
        for(Rock r:rocks) r.draw(g);

    }

    public static void main(String[] args) {
        new Tester();
    }
}

岩石class

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

public class Rock extends Rectangle{

    public static int sw, sh;

    public int dx, dy;
    public boolean isMoving;
    public BufferedImage sprite;
    //================================================= Constructors

    public Rock(int x, int y, int width, int height, int dx, int dy, boolean isMoving) {
        super();
        this.width = width;
        this.height = height;
        this.x = x;
        this.y = y;
        this.dx = dx;
        this.dy = dy;
        this.isMoving = isMoving;
        this.sprite = init();
    }

    //================================================= Methods
    public BufferedImage init(){
        BufferedImageLoader loader = new BufferedImageLoader();
        BufferedImage spriteSheet = null;
        try {
            spriteSheet = loader.loadImage("hero.png");
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        SpriteSheet ss = new SpriteSheet(spriteSheet);
        sprite = ss.grabSprite(0, 0, 32, 32);
        return sprite;
    }

    public void move() {
        if(isMoving == false) return;

        x += dx;
        y += dy;

        if(x + width > sw) {
            x = sw - width;
            dx = -dx;
        }

        if(y + height > sh) {
            y = sh - height;
            dy = -dy;
        }

        if(x < 0) {
            x = 0;
            dx = -dx;
        }

        if(y < 0) {
            y=0;
            dy = -dy;
        }
    }

    public Rock split(){
        Rock r = null;
        Random rnd = new Random();
        if(width > 20){
            dx=(rnd.nextBoolean()?1:-1);
            dy=(rnd.nextBoolean()?1:-1);
            r = new Rock(x,y,width,height,dx,dy,true);
        }

        return r;
    }

    public void draw(Graphics g) {
        g.drawImage(sprite,x,y,null);
    }

}

Answer 1

mouseEntered 问题的基本答案是...

mouseEntered会在鼠标进入组件时调用，当鼠标继续在组件内时永远不会调用。

相反，也许可以考虑使用 MouseMotionListener#mouseMoved，当鼠标移到您的组件上时它会告诉您。

你的第二个问题需要更多代码，特别是 SpriteSheet class，但我怀疑你需要知道你正在绘制的当前帧并简单地使用 SpriteSheet#grabSprite 来抓取框架的适当图像。

这需要你知道：

您尝试达到的每秒帧数
从循环开始经过的时间量（在这种情况下，一个循环是一秒）

这将允许您计算帧并从中计算您应该显示的图像

举个粗略的例子，你可以看看

使用鼠标输入

Using mouseEntered

java

swing

mouselistener