我正在尝试编写一个简单的电脑游戏程序。我无法获得导弹＆＃34;或＆＃34; bullet＆＃34;射出红色经典。
我认为我的问题是布尔部分。我对你看到的编码很新。 任何帮助将不胜感激！
右箭头和左箭头左右移动标准，主页和向上翻页键可以旋转标尺上的标尺，向上箭头可以使导弹射击。
到目前为止，这是我的代码：正如你所看到的，导弹只有在你向上箭头时才会闪烁
// This program is a simple video game that allows the user to
// attempt to indirectly shoot at a target, attempting to hit it.
//importing graphics
import java.awt.*;
public class Project2 {
public static final int SLEEP_TIME = 50;
// class constants below
// key movements
public static final int KEY_SPACE = 32;
public static final int KEY_PAGE_UP = 33;
public static final int KEY_HOME = 36;
public static final int KEY_LEFT_ARROW = 37;
public static final int KEY_UP_ARROW = 38;
public static final int KEY_RIGHT_ARROW = 39;
public static final int KEY_DOWN_ARROW = 40;
// panel size set here
public static final int PANEL_WIDTH = 300;
public static final int PANEL_HEIGHT = 300;
// The shooter
public static int SHOOTER_X;
public static final int SHOOTER_Y = PANEL_HEIGHT-30;
public static final int SHOOTER_SIZE = 20;
public static final int SHOOTER_INITIAL_X = 140;
// The target
public static int TARGET_X = 140;
public static final int TARGET_Y = PANEL_HEIGHT-280;
public static final int TARGET_SIZE = 20;
public static final int TARGET_INITIAL_X = 140;
// The gun
public static int GUN_SIZE = 10;
public static int Gun_Position_X = 0;
public static int Gun_Position_Y =PANEL_HEIGHT - GUN_SIZE;
public static int Gun_Initial_X = 0;
// The missile
public static final int MISSILE_SIZE = 4;
public static double MISSILE_SPEED = 0.1;
public static double missileDeltaX = 0;
public static double missileDeltaY = 0;
public static int missilePositionX = PANEL_WIDTH / 2;
public static int missilePositionY = PANEL_HEIGHT - 25;
public static boolean missileActive;
//color constants
public static final Color BACKGROUND_COLOR = Color.WHITE;
public static final Color SHOOTER_COLOR = Color.RED;
public static final Color TARGET_COLOR = Color.BLUE;
public static final Color MISSILE_COLOR = Color.BLACK;
//main method
public static void main(String[] args) {
DrawingPanel panel = new DrawingPanel(PANEL_WIDTH, PANEL_HEIGHT);
Graphics g = panel.getGraphics( );
initialize();
reset(g);
startGame(panel, g);
}
//starts up the game and calls the methods
public static void startGame(DrawingPanel panel, Graphics g) {
for (int i = 0; i <= 10000; i++) {
panel.sleep(50);
drawAll(g);
moveMissile(g, missileDeltaX);
drawShooter(g, SHOOTER_COLOR);
drawTarget(g, TARGET_COLOR);
handleKeys(panel,g);
}
}
// states my name and the project number in black
public static void drawAll(Graphics g) {
g.setColor(Color.BLACK);
g.drawString("Project 2 by Kathryn Johnston",10,15);
}
public static void initialize(){
//int SHOOTER_X = SHOOTER_INITIAL_X;
boolean missileActive = false;
}
//draws the shooter
public static void drawShooter(Graphics g, Color c) {
g.setColor(c);
g.fillOval(SHOOTER_X, SHOOTER_Y, SHOOTER_SIZE, SHOOTER_SIZE);
g.drawLine(Gun_Position_X+(SHOOTER_X+10), Gun_Position_Y - 30, SHOOTER_X+10, Gun_Position_Y-10);
}
//draws the target
public static void drawTarget(Graphics g, Color c) {
g.setColor(c);
g.fillOval(TARGET_X, TARGET_Y, TARGET_SIZE, TARGET_SIZE);
g.drawLine(TARGET_X-10,TARGET_Y+30,TARGET_X+30,TARGET_Y+30);
}
//input
public static void handleKeys(DrawingPanel panel, Graphics g) {
int keyCode = panel.getKeyCode();
if (keyCode == KEY_SPACE)
reset(g);
else if (keyCode == KEY_RIGHT_ARROW){
moveShooter(g,1);
moveMissile(g,1);
}
else if (keyCode == KEY_LEFT_ARROW){
moveShooter(g,-1);
moveMissile(g,-1);
}
else if (keyCode == KEY_HOME)
moveGun(g,-1);
else if (keyCode == KEY_PAGE_UP)
moveGun(g,1);
else if (keyCode == KEY_UP_ARROW){
shootMissile(g);
boolean missileActive = true;
}
}
// moves the shooter and re draws the background
public static void moveShooter(Graphics g, int deltaX) {
drawShooter(g, BACKGROUND_COLOR);
SHOOTER_X += deltaX;
if (SHOOTER_X < -SHOOTER_SIZE/2)
SHOOTER_X = -SHOOTER_SIZE/2;
if (SHOOTER_X >= PANEL_WIDTH - SHOOTER_SIZE/2)
SHOOTER_X = PANEL_WIDTH - SHOOTER_SIZE/2 - 1;
drawShooter(g, SHOOTER_COLOR);
}
// moves the gun
public static void moveGun(Graphics g, int deltaX) {
drawShooter(g, BACKGROUND_COLOR);
Gun_Position_X += deltaX;
if (Gun_Position_X < -GUN_SIZE)
Gun_Position_X = -GUN_SIZE;
if (Gun_Position_X > PANEL_WIDTH - GUN_SIZE/2)
Gun_Position_X = PANEL_WIDTH - GUN_SIZE/2 - 1;
drawShooter(g, SHOOTER_COLOR);
}
//fires the missle
public static void shootMissile(Graphics g) {
moveMissile(g, missileDeltaX);
missilePositionY += missileDeltaY;
if (missilePositionY < -MISSILE_SIZE)
missilePositionY = -MISSILE_SIZE;
if (missilePositionY > PANEL_HEIGHT - MISSILE_SIZE/2)
missilePositionY = PANEL_HEIGHT - MISSILE_SIZE/2 - 1;
drawMissile(g, MISSILE_COLOR);
}
//moves the missle
public static void moveMissile(Graphics g, double missileDeltaX) {
drawMissile(g, BACKGROUND_COLOR);
missilePositionX += missileDeltaX;
if (missilePositionX < -MISSILE_SIZE)
missilePositionX = -MISSILE_SIZE;
if (missilePositionX > PANEL_WIDTH - MISSILE_SIZE/2)
missilePositionX = PANEL_WIDTH - MISSILE_SIZE/2 - 1;
drawMissile(g, MISSILE_COLOR);
}
//draws the missle
public static void drawMissile(Graphics g, Color c) {
missilePositionX -= - missileDeltaY * MISSILE_SPEED;
missilePositionY -= missileDeltaX * MISSILE_SPEED;
g.setColor(c);
g.fillOval(missilePositionX, missilePositionY, MISSILE_SIZE, MISSILE_SIZE);
}
// reset method. this will reset everything's position
public static void reset(Graphics g) {
g.setColor(BACKGROUND_COLOR);
g.fillRect(0,0,PANEL_WIDTH,PANEL_HEIGHT);
SHOOTER_X = SHOOTER_INITIAL_X;
Gun_Position_X = Gun_Initial_X;
drawShooter(g,SHOOTER_COLOR);
}
}
答案 0 :(得分：2)
我找到了这段代码：
public static void initialize(){
boolean missileActive = false;
}
应该是：
public static void initialize(){
missileActive = false;
}
您正在创建该方法的本地boolean。
我还确定您不需要为密钥声明数字常量。见here.