Question

我遇到了这段代码的问题，如果有人能指出我正确的方向，我将非常感激。已经坚持了几天!!

基本上我试图阻止船一旦到达边界就移动。边界是6和-6。

这是代码。谢谢:)）

public void move (int direction) //if position exceeds 5 then playership will 
                                 //no long move in that direction.
{
    if (position > 5)
    {
        .... ?? What to write here?

    }
    else if (position < -5)
    {
        .... ?? What to write here?

    }

    position = position + direction;
    gun1.move(direction);
    gun2.move(direction);

}

Answer 1

问题取决于。如果你想在物体到达边界时停止它，那么就像......

// Move first
position = position + direction;

// Boundary check second...
if (position > 5)
{
     position = 5;
}
else if (position < -5)
{
     position = -5;
}

gun1.move(direction);
gun2.move(direction);

如果你想“反弹”墙壁......

// Move first
position = position + direction;

// Boundary check second...
if (position > 5)
{
     position = 5;
     direction *= -1
}
else if (position < -5)
{
     position = -5;
     direction *= -1
}

gun1.move(direction);
gun2.move(direction);

可能会工作 - 没有更多的背景很难说出来......

Answer 2

即使他试图离开边界，这也会让玩家保持在边界

public void move (int direction) //if position exceeds 5 then playership will 
                                 //no long move in that direction.
{
    if (position > 5)
    {
        position = 5;

    }
    else if (position < -5)
    {
        position = -5;

    }

    position = position + direction;
    gun1.move(direction);
    gun2.move(direction);

}

Answer 3

您的方法必须将状态（已移动或未移动）传达给调用代码。您可以通过以下两种方式完成此任务：

1返回状态代码

public int move (int direction) //if position exceeds 5 then playership will 
                                 //no long move in that direction.
{
    if (position > 5 || position <-5)
    {
        return -1;   //status code for no movement

    }

2当船不能移动时抛出异常

public void move (int direction) throws InvalidArgumentException//if position exceeds 5 then playership will 
                                 //no long move in that direction.
{
    if (position > 5 || position <-5)
    {
        throw new InvalidArgumentException("Cannot move!");   //status code for no movement

    }

调用代码可以处理状态代码/异常，看它是否合适。

如何在出界时让船停止移动？

3 个答案: