Question

我想要完成的是将1添加到shipX数组列表中的所有数字，问题是，如何？我希望在调用方法move()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进入类，以便move()可以访问当前值。您可以在move()方法中增加并调用您用于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repaint()上的JComponent方法确实需要从正确的Swing线程中调用，如this回答中所述。

如果您还尝试为动作制作动画，则可以查看Swing计时器上的Java Tutorial，按计划调用move()方法。您还可以使用按钮上的ActionListener来控制Timer或按钮，以便每次点击一次手动移动对象。

Answer 2

您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

逐一增加数字......

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]++;
}

如何将整数添加到数组中的整数

3 个答案: