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我正在尝试为游戏制作启动画面。我搜索了谷歌没有用。我在这里关注本教程,它对他有用。我的代码有点不同,但看起来有点像他的。这是我的代码:

游戏类:

import org.newdawn.slick.*;
import org.newdawn.slick.state.*;

public class Game extends StateBasedGame {

public static final String gamename = "Life - Alpha";
public static int menu = 1;
public static int play = 2;
public static int splash = 0;

public Game(String gamename) {
    super(gamename);
}

public void initStatesList(GameContainer gc) throws SlickException {
    this.getState(menu).init(gc, this);
    this.getState(play).init(gc, this);
    this.enterState(0);
}

public static void main(String[] args) {

    AppGameContainer app;
    try {
        app = new AppGameContainer(new Game(gamename));
        app.setDisplayMode(800, 600, false);
        app.start();
    } catch (SlickException e) {
        e.printStackTrace();
    }

   }
}

菜单类:

import org.lwjgl.input.Mouse;
import org.newdawn.slick.*;
import org.newdawn.slick.state.*;

public class Menu extends BasicGameState {

public Menu(int state) {

}

public void init(GameContainer gc, StateBasedGame sbg) throws SlickException {

}

public void render(GameContainer gc, StateBasedGame sbg, Graphics g) throws SlickException {

    Image back = new Image("res/Back.png");
    g.drawImage(back, 0, 0);

    Image panel = new Image("res/Panel.png");
    g.drawImage(panel, 240, 100);

    Image logo = new Image("res/Life Alpha.png");
    g.drawImage(logo, 290, 130);

    Image playButton = new Image("res/Play.png");
    g.drawImage(playButton, 330, 310);

    Image exitButton = new Image("res/Exit.png");
    g.drawImage(exitButton, 330, 370);

}

public void update(GameContainer gc, StateBasedGame sbg, int delta) throws SlickException {     

    Input input = gc.getInput();
    int xpos = Mouse.getX();
    int ypos = Mouse.getY();

    if((xpos > 330 && xpos < 480) && (ypos > 250 && ypos < 290)) {
        if(input.isMousePressed(0)) {
            sbg.enterState(2);
        }
    }
}

public int getID() {
    return 0;
}

}

游戏课:

import org.newdawn.slick.*;
import org.newdawn.slick.state.*;

public class Play extends BasicGameState {

public Play(int state) {

}

public void init(GameContainer gc, StateBasedGame sbg) throws SlickException {

}

public void render(GameContainer gc, StateBasedGame sbg, Graphics g) throws SlickException {

    Image back = new Image("res/Back.png");
    g.drawImage(back, 0, 0);

    Image panel = new Image("res/Panel2.png");
    g.drawImage(panel, 170, 100);

}

public void update(GameContainer gc, StateBasedGame sbg, int delta) throws SlickException {

}

public int getID() {
    return 1;
}

}

闪屏类:

import org.newdawn.slick.GameContainer;
import org.newdawn.slick.Graphics;
import org.newdawn.slick.Image;
import org.newdawn.slick.SlickException;
import org.newdawn.slick.state.BasicGameState;
import org.newdawn.slick.state.StateBasedGame;

public class SplashScreen extends BasicGameState {

Image splash;

private int elapsedTime;
private final int DELAY = 3000;

public SplashScreen(int state) {

}

public void init(GameContainer gc, StateBasedGame sbg) throws SlickException {

    splash = new Image("res/SplashScreen.png");

}

public void render(GameContainer gc, StateBasedGame sbg, Graphics g) throws SlickException {

    g.drawImage(splash, 0, 0);

}

public void update(GameContainer gc, StateBasedGame sbg, int delta) throws SlickException {

    elapsedTime += delta;

    if(elapsedTime >= DELAY) {

        sbg.enterState(1);

    }

}

public int getID() {
    return 0;
}

}

我得到的错误是:

2013 年 4 月 27 日星期六 22:48:01 EST 信息:Slick Build #274

2013 年 4 月 27 日星期六 22:48:01 EST 信息:LWJGL 版本:2.8.5

2013 年 4 月 27 日星期六 22:48:01 EST 信息:原始显示模式:1366 x 768 x 32 @60Hz

2013 年 4 月 27 日星期六 22:48:01 EST 信息:目标显示模式:800 x 600 x 0 @0Hz

2013 年 4 月 27 日星期六 22:48:01 EST 信息:开始显示 800x600

2013 年 4 月 27 日星期六 22:48:01 EST 信息:使用 Java PNG Loader = true

2013 年 4 月 27 日星期六 22:48:01 EST 信息:控制器不可用

线程“主”java.lang.NullPointerException 中的异常

在 mms001.Game.initStatesList(Game.java:18)

在 org.newdawn.slick.state.StateBasedGame.init(StateBasedGame.java:164)

在 org.newdawn.slick.AppGameContainer.setup(AppGameContainer.java:390)

在 org.newdawn.slick.AppGameContainer.start(AppGameContainer.java:314)

在 mms001.Game.main(Game.java:29)

4

1 回答 1

3

看起来这里可能有几个问题。

我注意到你的Menu班级返回 0 作为它的 ID,SplashScreen班级也是如此。我敢打赌,如果您将getIDclassMenu更改为 1,那将解决您的部分问题。

class Menu...
public int getID() {
    return 1;
}

您还需要更新 Play 类的 getID 方法以返回 2。

class Play...
public int getID() {
    return 2;
}

一旦你这样做,它们将匹配你在主类中定义的静态字段。

然后将您的initStatesList方法更新为 initsplash并进入menu状态

public void initStatesList(GameContainer gc) throws SlickException {
    this.getState(splash).init(gc, this);
    this.getState(menu).init(gc, this);
    this.getState(play).init(gc, this);

    this.enterState(menu);
}

希望这可以帮助。

于 2013-04-27T13:18:42.417 回答