Actual question on the bottom of the post!
起初,我想解释一下我的问题 .
我正在写一个基本的Snake游戏,我让蛇自动移动 . 当您执行代码时,它会自动移动到窗口的右侧,就像预期的那样 . 但是,我不能按照我想要的方式操纵我的蛇,它根本不会改变它的方向 .
为避免混淆, player
是类 Snake
的一个实例 .
解释蛇的运动:
Snake
对象具有 coordinates
属性,该属性是包含 SnakePart
对象的ArrayList . 每个 SnakePart
对象都具有 x
和 y
属性 . 使用此ArrayList,蛇通过在画布的y轴和x轴上使用 x
和 y
属性在画布上绘制小矩形来移动 .
Snake
对象还具有 dx
和 dy
属性,该属性被添加(或减去 - 取决于蛇的方向)到 SnakePart
对象的 x
和 y
属性,以使蛇向一个方向移动 .
要更新 Snake.java
中的ArrayList:
public void move() {
SnakePart head = new SnakePart(this.coordinates.get(0).x + this.dx, this.coordinates.get(0).y + this.dy);
this.coordinates.add(0, head);
this.coordinates.remove(this.coordinates.size() - 1);
}
要在 Board.java
画布上绘制蛇(部分原因,此时方法的其余部分不是必需的):
@Override
public void paintComponent(Graphics g) {
this.player.coordinates.forEach(snakePart -> {
g.setColor(Color.BLUE);
g.fillRect(snakePart.x, snakePart.y, 10, 10);
});
}
为了操纵蛇,我想使用箭头键 . 根据按下的箭头键,蛇的 x
和 y
坐标/属性被修改( Board.java
):
@Override
public void keyPressed(KeyEvent event) {
int keyCode = event.getKeyCode();
if (keyCode == 37) {
this.player.dx = -10;
this.player.dy = 0;
} else if (keyCode == 38) {
this.player.dx = 0;
this.player.dy = -10;
} else if (keyCode == 39) {
this.player.dx = 10;
this.player.dy = 0;
} else if (keyCode == 40) {
this.player.dx = 0;
this.player.dy = 10;
}
}
整码:
Snake.java
:
package com.codef0x.snake;
import java.util.ArrayList;
public class Snake {
ArrayList < SnakePart > coordinates;
int dx = 10;
int dy = 0;
public Snake(ArrayList < SnakePart > coords) {
this.coordinates = coords;
}
public void move() {
SnakePart head = new SnakePart(this.coordinates.get(0).x + this.dx, this.coordinates.get(0).y + this.dy);
this.coordinates.add(0, head);
this.coordinates.remove(this.coordinates.size() - 1);
}
public void grow() {
SnakePart newPart = new SnakePart(0, 0);
newPart.x = this.coordinates.get(this.coordinates.size() - 1).x - 10;
newPart.y = this.coordinates.get(this.coordinates.size() - 1).y;
this.coordinates.add(this.coordinates.size() - 1, newPart);
}
}
Board.java
(仅显示相关部分,否则代码太多)
package com.codef0x.snake;
import javax.swing.*;
import java.awt.*;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.util.ArrayList;
import java.util.Timer;
import java.util.TimerTask;
public class Board extends JPanel implements KeyListener {
Snake player;
ArrayList<SnakePart> snakeCoordinates;
public Board() {
this.snakeCoordinates = new ArrayList<>();
snakeCoordinates.add(new SnakePart(150, 150));
snakeCoordinates.add(new SnakePart(140, 150));
snakeCoordinates.add(new SnakePart(130, 150));
snakeCoordinates.add(new SnakePart(120, 150));
this.player = new Snake(snakeCoordinates);
this.food = new Food();
}
@Override
public void paintComponent(Graphics g) {
clear(g);
this.player.coordinates.forEach(snakePart - > {
g.setColor(Color.BLUE);
g.fillRect(snakePart.x, snakePart.y, 10, 10);
});
}
public void clear(Graphics g) {
g.clearRect(0, 0, getHeight(), getWidth());
}
@Override
public void update(Graphics g) {
paintComponent(g);
}
@Override
public void keyPressed(KeyEvent event) {
int keyCode = event.getKeyCode();
if (keyCode == 37) {
this.player.dx = -10;
this.player.dy = 0;
} else if (keyCode == 38) {
this.player.dx = 0;
this.player.dy = -10;
} else if (keyCode == 39) {
this.player.dx = 10;
this.player.dy = 0;
} else if (keyCode == 40) {
this.player.dx = 0;
this.player.dy = 10;
}
}
@Override
public void keyTyped(KeyEvent event) {
return;
}
@Override
public void keyReleased(KeyEvent event) {
return;
}
public void run(Board board) {
Timer game = new Timer();
game.schedule(new TimerTask() {
boolean initiallySpawned = false;
@Override
public void run() {
Graphics g = board.getGraphics();
if (hitSomething()) { // removed method hitSomething, not relevant
game.cancel();
return;
}
player.move();
update(g);
}
}, 0, 500);
}
}
SnakePart.java
:
package com.codef0x.snake;
public class SnakePart {
int x;
int y;
public SnakePart(int x, int y) {
this.x = x;
this.y = y;
}
}
我做错了什么,我需要改变什么才能正确地操纵蛇?
如果您仍然希望/需要查看所有文件,请在此处查看它们:
Snake.java
Board.java
SnakePart.java
Food.java < - 不相关,但可以防止对 Food
对象的混淆
1 回答
问题是主要的 . 您创建一个
board
来托管您的游戏状态,并创建不同的一个来聆听键盘 .它应该是:
另外
board.run(board)
没什么意义,在run
方法的范围内,板子可以交换到this
(并省略)...