如何在Java游戏库（Slick2D）中同时使用运动和动画

有人请帮帮我，我卡住了。我想按向上、右、左、下，然后朝那个方向移动我的动画，使它看起来像我的播放器正在行走。但这是我的问题，我提出了一个解决方案，但是Java会打开程序，然后很快关闭它。我知道这意味着有一个错误，但我不能阅读编译器错误消息，因为它没有说什么，它只是告诉我我的错误所在的行号。有人请帮帮我，我对此很失望

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



public class Play extends BasicGameState
{
    private SpriteSheet MoveRight; // initate a SprtieSheet
    private Animation MoveRightAni; // initate a Animation

    private SpriteSheet MoveLeft; // initate a SprtieSheet
    private Animation MoveLeftAni; // initate a Animation

    private SpriteSheet MoveUp; // initate a SprtieSheet
    private Animation MoveUpAni; // initate a Animation

    private SpriteSheet MoveDown; // initate a SprtieSheet
    private Animation MoveDownAni; // initate a Animation


    private Animation currentImage = MoveRightAni;

    private Image map; 
    public float x = 0;
    public float y = 0;




    public Play( int state){

    }


    public void init(GameContainer gc, StateBasedGame sbg) throws SlickException{
        MoveRight = new SpriteSheet("test/MoveRight.png",21,24); // declare a SpriteSheet and load it into java with its dimentions
        MoveRightAni = new Animation(MoveRight, 400); // declare a Animation, loading the SpriteSheet and inputing the Animation Speed

        MoveLeft = new SpriteSheet("test/MoveLeft.png",21,24); // declare a SpriteSheet and load it into java with its dimentions
        MoveLeftAni = new Animation(MoveLeft, 400); // declare a Animation, loading the SpriteSheet and inputing the Animation Speed

        MoveUp = new SpriteSheet("test/MoveUp.png",21,24); // declare a SpriteSheet and load it into java with its dimentions
        MoveUpAni = new Animation(MoveUp, 400); // declare a Animation, loading the SpriteSheet and inputing the Animation Speed

        MoveDown = new SpriteSheet("test/MoveDown.png",21,24); // declare a SpriteSheet and load it into java with its dimentions
        MoveDownAni = new Animation(MoveDown, 400); // declare a Animation, loading the SpriteSheet and inputing the Animation Speed

        map = new Image("test/map.png");



    }


    public void render(GameContainer gc, StateBasedGame sbg, Graphics g) throws SlickException{
        g.drawImage(map, 0, 0);
        currentImage.draw(x,y);



    }

    public void update (GameContainer gc, StateBasedGame sbg, int delta) throws SlickException
    {
        MoveRightAni.update(delta); // this line makes sure the speed of the Animation is true
        MoveUpAni.update(delta); // this line makes sure the speed of the Animation is true
        MoveLeftAni.update(delta); // this line makes sure the speed of the Animation is true
        MoveDownAni.update(delta); // this line makes sure the speed of the Animation is true
        Input input = gc.getInput();

        if (input.isKeyDown(Input.KEY_W))
        {
            y -= 0.1 * delta;
            currentImage = MoveUpAni;

        }
        if (input.isKeyDown(Input.KEY_A))
        {
            x -= 0.1 * delta;
            currentImage = MoveLeftAni;
        }
        if (input.isKeyDown(Input.KEY_D))
        {
            x += 0.1 * delta;
            currentImage = MoveRightAni;
        }
        if (input.isKeyDown(Input.KEY_S))
        {
            y += 0.1 * delta;
            currentImage = MoveDownAni;
        }


    }
    public int getID(){
        return 0;
    }
}

---

您的问题是试图将全局变量currentImage初始化为尚未初始化的动画。使用slick，您需要在init方法中处理初始化问题。使用java编程时，在尝试使用变量初始化另一个变量之前，请始终初始化变量

要解决您的问题，请更改：

private Animation currentImage = MoveRightAni;

致：

在您的init方法中，在map=之后的最后一行

currentImage = MoveRightAni;

---

这可能有助于发布错误所指的行。发布堆栈跟踪提供给您的所有内容。从我所看到的来看，您的代码看起来足够好，可以按预期运行。org.newdawn.slick.SlickException:Game.render failure-检查游戏代码。java.lang.nullpointerException非常感谢，我不知道我怎么会错过它：我真的很感谢，谢谢，没问题。别忘了接受答案：

currentImage = MoveRightAni;