Question

我的代码是：

public void move() {
    moveX();
    moveY();
}

public void moveX() {
    if(xMove > 0) {
        int tx = (int) (x + xMove + bounds.x + bounds.width) / Tile.TILEWIDTH;

        if(!collisionWithTile(tx, (int) (y + bounds.y) / Tile.TILEHEIGHT) && !collisionWithTile(tx, (int) (y + bounds.y + bounds.height) / Tile.TILEHEIGHT)) {
            x += xMove;
        }
    } else if(xMove < 0) {
        int tx = (int) (x + xMove + bounds.x) / Tile.TILEWIDTH;

        if(!collisionWithTile(tx, (int) (y + bounds.y) / Tile.TILEHEIGHT) && !collisionWithTile(tx, (int) (y + bounds.y + bounds.height) / Tile.TILEHEIGHT)) {
            x += xMove;
        }


    }

}

public void moveY() {
    if(yMove < 0) {
        int ty = (int) (y + yMove + bounds.y + bounds.height) / Tile.TILEHEIGHT;

        if(!collisionWithTile((int) (x + bounds.x) / Tile.TILEHEIGHT, ty) && !collisionWithTile((int) (x + bounds.x + bounds.width) / Tile.TILEWIDTH, ty)) {
            y += yMove;
        }
    }

    if(yMove > 0) {
        int ty = (int) (y + yMove + bounds.y) / Tile.TILEHEIGHT;

        if(!collisionWithTile((int) (x + bounds.x) / Tile.TILEHEIGHT, ty) && !collisionWithTile((int) (x + bounds.x + bounds.width) / Tile.TILEWIDTH, ty)) {
            y += yMove;
        }
    }
}

protected boolean collisionWithTile(int x, int y) {
    return room.getTile(x, y).isSolid();
}

但是当我运行它时，我得到了这个StackTrace的NullPointerException： Exception in thread "Thread-0" java.lang.NullPointerException at com.pixelandbitgames.entities.creature.Creature.collisionWithTile(Creature.java:69) at com.pixelandbitgames.entities.creature.Creature.moveX(Creature.java:41) at com.pixelandbitgames.entities.creature.Creature.move(Creature.java:27) at com.pixelandbitgames.entities.creature.Player.tick(Player.java:19) at com.pixelandbitgames.states.GameState.tick(GameState.java:23) at com.pixelandbitgames.game.Game.tick(Game.java:72) at com.pixelandbitgames.game.Game.run(Game.java:113) at java.lang.Thread.run(Thread.java:748) 我看不到这是哪里来的，因为crashWithTile已填满所有参数。如果有人可以帮助我，那将是可取的。如果有人需要其他任何帮助，我会提供。我的其他班级似乎还不错，仅此而已。当我尝试移动时会发生这种情况。我的Room.getTile代码在这里：

public Tile getTile(int x, int y) {
    if(x < 0 || y < 0 || x >= width || y >= height)
        return Tile.floorTile;
    Tile t = Tile.tiles[tiles[x][y]];
    if(t == null)
        return Tile.floorTile;
    return t;
}

，这无法返回null。除非被覆盖，否则solid只是返回true。

public boolean isSolid() {
    return false;
}

Answer 1

room为 null ，或者room.getTile(x, y)返回 null 。您尚未粘贴其中的相关内容，因此无法提供更多信息。

Unknown NullPointerException 10忽略>

1 个答案: