基于Nokia S40的猜数字游戏之一[4]

    public String getLabel()
    {
        return label;
    }
   
    public void setMargin(int x,int y)
    {
        this.marginx = x;
        this.marginy = y;
    }
    protected void paintArea(Graphics g, boolean hasFocus)
    {
        g.setStrokeStyle(Graphics.SOLID);
        g.drawRect(x, y, w - 1, h - 1);

      
       
        if (selected)
        {
            g.setColor(getForeColor());
            g.fillRect(x, y, w - 1, h - 1);
            g.setColor(getBackColor());
        } else if (hasFocus)
        {
            g.setStrokeStyle(Graphics.DOTTED);
            g.drawRect(x + 3, y + 3, w - 7, h - 7);
            g.setStrokeStyle(Graphics.SOLID);
        }

        g.drawString(label, x + marginx, y + marginy, Graphics.TOP | Graphics.LEFT);
    }

    public void keyPressed(int keyCode)
    {
        int num = keyCode - 48;
        if (num >= 0)
        {
            if (modifiable)
            {
                this.label = num + "";
            }
            repaintArea(this, true);
            moveFocus(true);
            return;
        }

        int action = getGameAction(keyCode);
        switch (action)
        {
        case UP:
        case LEFT:
            moveFocus(false);
            break;
        case DOWN:
        case RIGHT:
            moveFocus(true);
            break;
        case FIRE:
            if (listener != null)
            {
                listener.buttonPressed(this);
            }
            break;
        }

    }

    public void setLabel(String s)
    {
        this.label = s;
    }

    public void keyReleased(int keyCode)
    {

    }

    public void setListener(ButtonListener listener)
    {
        this.listener = listener;
    }
}

我们应该重点关注一下paintArea()方法，以及keyPressed()方法。如果我们注册了一个ButtonListener给Button的话，那么当按键事件发生的时候，buttonPressed()方法就会触发并且把这个按键传递给他，这样我们应用程序就可以根据用户的事件来处理相关的逻辑了。