如何将整数添加到数组中的整数

Question

我想要完成的是将1 添加到shipX 数组列表中的所有数字中，问题是，如何？我想在调用 move() 方法时执行此操作，但我将如何实现这一点，因为我是数组的新手

class Ship
{
    public void paint(Graphics g)
    {
        int shipX[] = {500,485,500,515,500};
        int shipY[] = {500,485,455,485,500};
        g.setColor(Color.cyan);
        g.fillPolygon(shipX, shipY, 5);
    }
    public void move()
    {
    }
}

Answer 1

首先，您必须将数组移动到paint() 的本地范围之外的点并移到类中，以便move() 可以访问当前值。您将增加 move() 方法并调用您用来重绘组件的任何例程。

class Ship
{
    //make your polygon points members of the class
    //so that you can have state that changes
    //instead of declaring them in the paint method
    int shipX[] = {500,485,500,515,500};
    int shipY[] = {500,485,455,485,500};
    //set these to the amount you want per update. They can even be negative 
    int velocityX = 1;
    int velocityY = 1;

    public void paint(Graphics g)
    {
        g.setColor(Color.cyan);
        g.fillPolygon(shipX, shipY, 5);
    }

    public void move()
    {
        //add 1 to each value in shipX
        for (int i=0; i<shipX.length; i++)
        {
            shipX[i] += velocityX;
        }
        //add 1 to each value in shipY
        for (int i=0; i<shipY.length;i++)
        {
            shipY[i] += velocityY;
        }
        //call whatever you use to force a repaint
        //normally I would assume your class extended
        //javax.swing.JComponent, but you don't show it in your code
        //if so, just uncomment:
        //this.repaint();
    }
}

虽然我应该指出JComponent 上的repaint() 方法确实需要从正确的Swing 线程中调用，正如this 答案中所指出的那样。

如果您还尝试为运动设置动画，您可以查看 Swing 计时器上的 Java Tutorial 以按计划调用您的 move() 方法。您还可以在按钮上使用ActionListener 来控制Timer，或者在按钮上使用每次点击手动移动对象一次。

Answer 2

你所要做的就是遍历数组并修改每个索引的值：

for (int i = 0; i < shipX.length; i++)
{
    shipX[i]++;
}

Answer 3

一个一个地增加数字...

for (i=0; i<shipX.length; i++)
{
   shipX[i]++; // same as shipX[i] = shipX[i] +1
}

for (i=0; i<shipY.length;i++)
{
   shipY[i]++;
}