Question

我一直在使用Gridworld在Eclipse中创建Checkers游戏。到目前为止，我只修改过红色碎片。我的目标是能够移动（）片段并让它们选择是跳跃还是跳跃。显然，跳跃（即当棋子移动一段相反的颜色然后从网格中移除该棋子时）优先于踩踏。我的问题是，每当我尝试移动前两列或最后两列中的碎片时，我都会收到Illegal Out of Bounds错误。谁能帮我解决这个问题？谢谢，麻烦您了。

import java.awt.Color;
import info.gridworld.actor.Actor;
import info.gridworld.actor.Bug;
import info.gridworld.actor.Critter;
import info.gridworld.actor.Flower;
import info.gridworld.grid.Grid;
import info.gridworld.grid.Location;

public class RedPieces extends Bug {
boolean jumped;

public RedPieces() {
    setColor(Color.red);
    setDirection(180);
    jumped = false;
}

public boolean canMove() {
    Grid<Actor> gr = getGrid();
    if (gr == null)
        return false;
    Location loc1 = getLocation();
    if (getGrid().get(new Location(loc1.getRow() + 1, loc1.getCol() - 1)) == null || 
        getGrid().get(new Location(loc1.getRow() + 1, loc1.getCol() - 1)).getColor() == Color.black || 
        getGrid().get(new Location(loc1.getRow() + 1, loc1.getCol() + 1)) == null || 
        getGrid().get(new Location(loc1.getRow() + 1, loc1.getCol() + 1)).getColor() == Color.black) {
        return true;
    }
    return false;
}

public boolean jump2(Location loc){
    Grid<Actor> gr = getGrid();
    if (gr == null)
        return false;
    Location jump1 = new Location(loc.getRow() + 2, loc.getCol() - 2);
    Location jump2 = new Location(loc.getRow() + 2, loc.getCol() + 2);

    if( (gr.isValid(jump1)) && 
        (gr.get(jump1) == null) && 
        (gr.get(jump2) == null) && 
        (gr.get(new Location(loc.getRow() + 1, loc.getCol() -1)) instanceof BlackPieces) && 
        ((gr.get(new Location(loc.getRow() + 1, loc.getCol() + 1)) == null) || 
         (gr.get(new Location(loc.getRow() + 1, loc.getCol() + 1))) instanceof RedPieces))
    {
        gr.get(new Location(loc.getRow() + 1, loc.getCol() -1)).removeSelfFromGrid();
        moveTo(jump1);
        return true;
    }
    else if( (gr.isValid(jump2)) && 
             (gr.get(jump2) == null) && 
             (gr.get(jump1) == null) && 
             (gr.get(new Location(loc.getRow() + 1, loc.getCol() +1)) instanceof BlackPieces) && 
             ((gr.get(new Location(loc.getRow() +1, loc.getCol() - 1)) == null) || 
              (gr.get(new Location(loc.getRow() + 1, loc.getCol() -1)) instanceof RedPieces)))
    {
        gr.get(new Location(loc.getRow() + 1, loc.getCol() +1)).removeSelfFromGrid();
        moveTo(jump2);
        return true;
    }
    else if((gr.isValid(jump1) && gr.get(jump1) == null) && 
            (gr.isValid(jump2) && gr.get(jump2) != null))
    {
        if(gr.get(new Location(loc.getRow() + 1, loc.getCol() -1)) instanceof BlackPieces)
        {
            gr.get(new Location(loc.getRow() + 1, loc.getCol() -1)).removeSelfFromGrid();
            moveTo(jump1);
            return true;
        }
    }
    else if((gr.isValid(jump2) && gr.get(jump2) == null) && 
            (gr.isValid(jump1) && gr.get(jump1) != null))
    {
        if(gr.get(new Location(loc.getRow() + 1, loc.getCol() +1)) instanceof BlackPieces)
        {
            gr.get(new Location(loc.getRow() + 1, loc.getCol() +1)).removeSelfFromGrid();
            moveTo(jump2);
            return true;
        }
    }

    return false;
}

public void move() {
    Grid<Actor> gr = getGrid();
    if (gr == null)
        return;

    Location loc = getLocation();
    Location next1 = new Location(loc.getRow() + 1, loc.getCol() - 1);
    Location next2 = new Location(loc.getRow() + 1, loc.getCol() + 1);
    if (jump2(loc) == false) {
        if (gr.isValid(next2) && gr.get(next2) == null && 
            gr.isValid(next1) && gr.get(next1) != null)
        {
            moveTo(next2);
        }
        else if (gr.isValid(next1) && gr.get(next1) == null && 
                 gr.isValid(next1) && gr.get(next2) != null)
        {
            moveTo(next1);
        }
        else if (gr.isValid(next1) && gr.get(next1) == null && 
                 gr.isValid(next2) && gr.get(next2) == null)
        {
            moveTo(randomLoc(next1, next2));
        }
        else
            return;
    }
}

public static Location randomLoc(Location loc1, Location loc2) {
    double num = Math.random();
    if (num < 0.5)
        return loc1;
    else
        return loc2;
}

public void act() {
    if(canMove()) move();
}
}

Answer 1

必须重新格式化代码才能提高可读性。通过这样做，我发现了一些潜在的错误。

在jump2()方法中，第二个if语句不会检查jump2的有效性。它可能是gr.get(jump2 == null)语句中if条件异常的原因。
同样的逻辑适用于后续的else if语句。这次，您没有检查jump1。
在move()方法中，第一个else if，您只检查next1两次的有效性，这似乎是一个错误。请在问题中重新格式化的代码中找到它。

总的来说，我认为您需要将if条件修改为尽可能简单（可读）。重新格式化也会有所帮助。

[已添加]两件小事。

在canMove()方法中，仅在第一个gr语句中使用if。您在第二个getGrid()声明中使用的是gr而不是if。
每次在new Location语句中获得网格时，你都不能避免做if吗？您正在使用这些网格而不检查其有效性。你确定它们有效吗？您可以在方法的开头创建它们，检查它们的有效性，并在if语句中使用它们。它也可能有助于if语句的可读性。

[添加更多] jump2()方法简化示例

以下代码忽略列的另一面（无效，null或红色部分）。根据我的假设，当一方有效跳过黑色棋子时，其他方面的情况并不重要。

public boolean jump2(Location loc){
    Grid<Actor> gr = getGrid();
    if (gr == null)
        return false;

    Location jump1 = new Location(loc.getRow() + 2, loc.getCol() - 2);
    Location jump2 = new Location(loc.getRow() + 2, loc.getCol() + 2);
    Location adjacent1 = new Location(loc.getRow() + 1, loc.getCol() - 1);
    Location adjacent2 = new Location(loc.getRow() + 1, loc.getCol() + 1);

    // try one column
    if( gr.isValid(jump1))
    {
        if( (gr.get(jump1) == null) && 
            (gr.get(adjacent1) instanceof BlackPieces))
        {
            gr.get(adjacent1).removeSelfFromGrid();
            moveTo(jump1);
            return true;
        }
    }

    // try the other column
    if( gr.isValid(jump2))
    {
        if( (gr.get(jump2) == null) && 
             (gr.get(adjacent2) instanceof BlackPieces))
        {
            gr.get(adjacent2).removeSelfFromGrid();
            moveTo(jump2);
            return true;
        }
    }

    return false;
}

Checkers Game（Java）使用Gridworld

1 个答案: