随机和图形太长的代码

Question

我想创建一个随机数，然后创建9个矩形，但其中一个将采用不同的颜色，一个颜色不同的将根据随机数出来，所以我已经完成但是代码太长了，我怎么能缩短它？

public void paint(Graphics g) {
    rand = new Random();
    n = rand.nextInt(9) + 1;
    if (n == 1) {
        g.setColor(Color.LIGHT_GRAY);
        rec1 = new Rectangle(10, 130, 50, 50);
        g.fillRect((int) rec1.getX(), (int) rec1.getY(),
                (int) rec1.getWidth(), (int) rec1.getHeight());
        g.setColor(Color.DARK_GRAY);
        rec2 = new Rectangle(70, 130, 50, 50);
        g.fillRect((int) rec2.getX(), (int) rec2.getY(),
                (int) rec2.getWidth(), (int) rec2.getHeight());
        rec3 = new Rectangle(130, 130, 50, 50);
        g.fillRect((int) rec3.getX(), (int) rec3.getY(),
                (int) rec3.getWidth(), (int) rec3.getHeight());
        rec4 = new Rectangle(10, 70, 50, 50);
        g.fillRect((int) rec4.getX(), (int) rec4.getY(),
                (int) rec4.getWidth(), (int) rec4.getHeight());
        rec5 = new Rectangle(70, 70, 50, 50);
        g.fillRect((int) rec5.getX(), (int) rec5.getY(),
                (int) rec5.getWidth(), (int) rec5.getHeight());
        rec6 = new Rectangle(130, 70, 50, 50);
        g.fillRect((int) rec6.getX(), (int) rec6.getY(),
                (int) rec6.getWidth(), (int) rec6.getHeight());
        rec7 = new Rectangle(10, 10, 50, 50);
        g.fillRect((int) rec7.getX(), (int) rec7.getY(),
                (int) rec7.getWidth(), (int) rec7.getHeight());
        rec8 = new Rectangle(70, 10, 50, 50);
        g.fillRect((int) rec8.getX(), (int) rec8.getY(),
                (int) rec8.getWidth(), (int) rec8.getHeight());
        rec9 = new Rectangle(130, 10, 50, 50);
        g.fillRect((int) rec9.getX(), (int) rec9.getY(),
                (int) rec9.getWidth(), (int) rec9.getHeight());
    } else if (n == 2) {
        rec1 = new Rectangle(10, 130, 50, 50);
        g.fillRect((int) rec1.getX(), (int) rec1.getY(),
                (int) rec1.getWidth(), (int) rec1.getHeight());
        g.setColor(Color.LIGHT_GRAY);
        rec2 = new Rectangle(70, 130, 50, 50);
        g.fillRect((int) rec2.getX(), (int) rec2.getY(),
                (int) rec2.getWidth(), (int) rec2.getHeight());
        g.setColor(Color.DARK_GRAY);
        rec3 = new Rectangle(130, 130, 50, 50);
        g.fillRect((int) rec3.getX(), (int) rec3.getY(),
                (int) rec3.getWidth(), (int) rec3.getHeight());
        rec4 = new Rectangle(10, 70, 50, 50);
        g.fillRect((int) rec4.getX(), (int) rec4.getY(),
                (int) rec4.getWidth(), (int) rec4.getHeight());
        rec5 = new Rectangle(70, 70, 50, 50);
        g.fillRect((int) rec5.getX(), (int) rec5.getY(),
                (int) rec5.getWidth(), (int) rec5.getHeight());
        rec6 = new Rectangle(130, 70, 50, 50);
        g.fillRect((int) rec6.getX(), (int) rec6.getY(),
                (int) rec6.getWidth(), (int) rec6.getHeight());
        rec7 = new Rectangle(10, 10, 50, 50);
        g.fillRect((int) rec7.getX(), (int) rec7.getY(),
                (int) rec7.getWidth(), (int) rec7.getHeight());
        rec8 = new Rectangle(70, 10, 50, 50);
        g.fillRect((int) rec8.getX(), (int) rec8.getY(),
                (int) rec8.getWidth(), (int) rec8.getHeight());
        rec9 = new Rectangle(130, 10, 50, 50);
        g.fillRect((int) rec9.getX(), (int) rec9.getY(),
                (int) rec9.getWidth(), (int) rec9.getHeight());
    } else if (n == 3) {
        rec1 = new Rectangle(10, 130, 50, 50);
        g.fillRect((int) rec1.getX(), (int) rec1.getY(),
                (int) rec1.getWidth(), (int) rec1.getHeight());
        rec2 = new Rectangle(70, 130, 50, 50);
        g.fillRect((int) rec2.getX(), (int) rec2.getY(),
                (int) rec2.getWidth(), (int) rec2.getHeight());
        g.setColor(Color.LIGHT_GRAY);
        rec3 = new Rectangle(130, 130, 50, 50);
        g.fillRect((int) rec3.getX(), (int) rec3.getY(),
                (int) rec3.getWidth(), (int) rec3.getHeight());
        g.setColor(Color.DARK_GRAY);
        rec4 = new Rectangle(10, 70, 50, 50);
        g.fillRect((int) rec4.getX(), (int) rec4.getY(),
                (int) rec4.getWidth(), (int) rec4.getHeight());
        rec5 = new Rectangle(70, 70, 50, 50);
        g.fillRect((int) rec5.getX(), (int) rec5.getY(),
                (int) rec5.getWidth(), (int) rec5.getHeight());
        rec6 = new Rectangle(130, 70, 50, 50);
        g.fillRect((int) rec6.getX(), (int) rec6.getY(),
                (int) rec6.getWidth(), (int) rec6.getHeight());
        rec7 = new Rectangle(10, 10, 50, 50);
        g.fillRect((int) rec7.getX(), (int) rec7.getY(),
                (int) rec7.getWidth(), (int) rec7.getHeight());
        rec8 = new Rectangle(70, 10, 50, 50);
        g.fillRect((int) rec8.getX(), (int) rec8.getY(),
                (int) rec8.getWidth(), (int) rec8.getHeight());
        rec9 = new Rectangle(130, 10, 50, 50);
        g.fillRect((int) rec9.getX(), (int) rec9.getY(),
                (int) rec9.getWidth(), (int) rec9.getHeight());
    } else if (n == 4) {
        rec1 = new Rectangle(10, 130, 50, 50);
        g.fillRect((int) rec1.getX(), (int) rec1.getY(),
                (int) rec1.getWidth(), (int) rec1.getHeight());
        rec2 = new Rectangle(70, 130, 50, 50);
        g.fillRect((int) rec2.getX(), (int) rec2.getY(),
                (int) rec2.getWidth(), (int) rec2.getHeight());
        rec3 = new Rectangle(130, 130, 50, 50);
        g.fillRect((int) rec3.getX(), (int) rec3.getY(),
                (int) rec3.getWidth(), (int) rec3.getHeight());
        g.setColor(Color.LIGHT_GRAY);
        rec4 = new Rectangle(10, 70, 50, 50);
        g.fillRect((int) rec4.getX(), (int) rec4.getY(),
                (int) rec4.getWidth(), (int) rec4.getHeight());
        g.setColor(Color.DARK_GRAY);
        rec5 = new Rectangle(70, 70, 50, 50);
        g.fillRect((int) rec5.getX(), (int) rec5.getY(),
                (int) rec5.getWidth(), (int) rec5.getHeight());
        rec6 = new Rectangle(130, 70, 50, 50);
        g.fillRect((int) rec6.getX(), (int) rec6.getY(),
                (int) rec6.getWidth(), (int) rec6.getHeight());
        rec7 = new Rectangle(10, 10, 50, 50);
        g.fillRect((int) rec7.getX(), (int) rec7.getY(),
                (int) rec7.getWidth(), (int) rec7.getHeight());
        rec8 = new Rectangle(70, 10, 50, 50);
        g.fillRect((int) rec8.getX(), (int) rec8.getY(),
                (int) rec8.getWidth(), (int) rec8.getHeight());
        rec9 = new Rectangle(130, 10, 50, 50);
        g.fillRect((int) rec9.getX(), (int) rec9.getY(),
                (int) rec9.getWidth(), (int) rec9.getHeight());
    } else if (n == 5) {
        rec1 = new Rectangle(10, 130, 50, 50);
        g.fillRect((int) rec1.getX(), (int) rec1.getY(),
                (int) rec1.getWidth(), (int) rec1.getHeight());
        rec2 = new Rectangle(70, 130, 50, 50);
        g.fillRect((int) rec2.getX(), (int) rec2.getY(),
                (int) rec2.getWidth(), (int) rec2.getHeight());
        rec3 = new Rectangle(130, 130, 50, 50);
        g.fillRect((int) rec3.getX(), (int) rec3.getY(),
                (int) rec3.getWidth(), (int) rec3.getHeight());
        rec4 = new Rectangle(10, 70, 50, 50);
        g.fillRect((int) rec4.getX(), (int) rec4.getY(),
                (int) rec4.getWidth(), (int) rec4.getHeight());
        g.setColor(Color.LIGHT_GRAY);
        rec5 = new Rectangle(70, 70, 50, 50);
        g.fillRect((int) rec5.getX(), (int) rec5.getY(),
                (int) rec5.getWidth(), (int) rec5.getHeight());
        g.setColor(Color.DARK_GRAY);
        rec6 = new Rectangle(130, 70, 50, 50);
        g.fillRect((int) rec6.getX(), (int) rec6.getY(),
                (int) rec6.getWidth(), (int) rec6.getHeight());
        rec7 = new Rectangle(10, 10, 50, 50);
        g.fillRect((int) rec7.getX(), (int) rec7.getY(),
                (int) rec7.getWidth(), (int) rec7.getHeight());
        rec8 = new Rectangle(70, 10, 50, 50);
        g.fillRect((int) rec8.getX(), (int) rec8.getY(),
                (int) rec8.getWidth(), (int) rec8.getHeight());
        rec9 = new Rectangle(130, 10, 50, 50);
        g.fillRect((int) rec9.getX(), (int) rec9.getY(),
                (int) rec9.getWidth(), (int) rec9.getHeight());
    } else if (n == 6) {
        rec1 = new Rectangle(10, 130, 50, 50);
        g.fillRect((int) rec1.getX(), (int) rec1.getY(),
                (int) rec1.getWidth(), (int) rec1.getHeight());
        rec2 = new Rectangle(70, 130, 50, 50);
        g.fillRect((int) rec2.getX(), (int) rec2.getY(),
                (int) rec2.getWidth(), (int) rec2.getHeight());
        rec3 = new Rectangle(130, 130, 50, 50);
        g.fillRect((int) rec3.getX(), (int) rec3.getY(),
                (int) rec3.getWidth(), (int) rec3.getHeight());
        rec4 = new Rectangle(10, 70, 50, 50);
        g.fillRect((int) rec4.getX(), (int) rec4.getY(),
                (int) rec4.getWidth(), (int) rec4.getHeight());
        rec5 = new Rectangle(70, 70, 50, 50);
        g.fillRect((int) rec5.getX(), (int) rec5.getY(),
                (int) rec5.getWidth(), (int) rec5.getHeight());
        g.setColor(Color.LIGHT_GRAY);
        rec6 = new Rectangle(130, 70, 50, 50);
        g.fillRect((int) rec6.getX(), (int) rec6.getY(),
                (int) rec6.getWidth(), (int) rec6.getHeight());
        g.setColor(Color.DARK_GRAY);
        rec7 = new Rectangle(10, 10, 50, 50);
        g.fillRect((int) rec7.getX(), (int) rec7.getY(),
                (int) rec7.getWidth(), (int) rec7.getHeight());
        rec8 = new Rectangle(70, 10, 50, 50);
        g.fillRect((int) rec8.getX(), (int) rec8.getY(),
                (int) rec8.getWidth(), (int) rec8.getHeight());
        rec9 = new Rectangle(130, 10, 50, 50);
        g.fillRect((int) rec9.getX(), (int) rec9.getY(),
                (int) rec9.getWidth(), (int) rec9.getHeight());
    } else if (n == 7) {
        rec1 = new Rectangle(10, 130, 50, 50);
        g.fillRect((int) rec1.getX(), (int) rec1.getY(),
                (int) rec1.getWidth(), (int) rec1.getHeight());
        rec2 = new Rectangle(70, 130, 50, 50);
        g.fillRect((int) rec2.getX(), (int) rec2.getY(),
                (int) rec2.getWidth(), (int) rec2.getHeight());
        rec3 = new Rectangle(130, 130, 50, 50);
        g.fillRect((int) rec3.getX(), (int) rec3.getY(),
                (int) rec3.getWidth(), (int) rec3.getHeight());
        rec4 = new Rectangle(10, 70, 50, 50);
        g.fillRect((int) rec4.getX(), (int) rec4.getY(),
                (int) rec4.getWidth(), (int) rec4.getHeight());
        rec5 = new Rectangle(70, 70, 50, 50);
        g.fillRect((int) rec5.getX(), (int) rec5.getY(),
                (int) rec5.getWidth(), (int) rec5.getHeight());
        rec6 = new Rectangle(130, 70, 50, 50);
        g.fillRect((int) rec6.getX(), (int) rec6.getY(),
                (int) rec6.getWidth(), (int) rec6.getHeight());
        g.setColor(Color.LIGHT_GRAY);
        rec7 = new Rectangle(10, 10, 50, 50);
        g.fillRect((int) rec7.getX(), (int) rec7.getY(),
                (int) rec7.getWidth(), (int) rec7.getHeight());
        g.setColor(Color.DARK_GRAY);
        rec8 = new Rectangle(70, 10, 50, 50);
        g.fillRect((int) rec8.getX(), (int) rec8.getY(),
                (int) rec8.getWidth(), (int) rec8.getHeight());
        rec9 = new Rectangle(130, 10, 50, 50);
        g.fillRect((int) rec9.getX(), (int) rec9.getY(),
                (int) rec9.getWidth(), (int) rec9.getHeight());
    } else if (n == 8) {
        rec1 = new Rectangle(10, 130, 50, 50);
        g.fillRect((int) rec1.getX(), (int) rec1.getY(),
                (int) rec1.getWidth(), (int) rec1.getHeight());
        rec2 = new Rectangle(70, 130, 50, 50);
        g.fillRect((int) rec2.getX(), (int) rec2.getY(),
                (int) rec2.getWidth(), (int) rec2.getHeight());
        rec3 = new Rectangle(130, 130, 50, 50);
        g.fillRect((int) rec3.getX(), (int) rec3.getY(),
                (int) rec3.getWidth(), (int) rec3.getHeight());
        rec4 = new Rectangle(10, 70, 50, 50);
        g.fillRect((int) rec4.getX(), (int) rec4.getY(),
                (int) rec4.getWidth(), (int) rec4.getHeight());
        rec5 = new Rectangle(70, 70, 50, 50);
        g.fillRect((int) rec5.getX(), (int) rec5.getY(),
                (int) rec5.getWidth(), (int) rec5.getHeight());
        rec6 = new Rectangle(130, 70, 50, 50);
        g.fillRect((int) rec6.getX(), (int) rec6.getY(),
                (int) rec6.getWidth(), (int) rec6.getHeight());
        rec7 = new Rectangle(10, 10, 50, 50);
        g.fillRect((int) rec7.getX(), (int) rec7.getY(),
                (int) rec7.getWidth(), (int) rec7.getHeight());
        g.setColor(Color.LIGHT_GRAY);
        rec8 = new Rectangle(70, 10, 50, 50);
        g.fillRect((int) rec8.getX(), (int) rec8.getY(),
                (int) rec8.getWidth(), (int) rec8.getHeight());
        g.setColor(Color.DARK_GRAY);
        rec9 = new Rectangle(130, 10, 50, 50);
        g.fillRect((int) rec9.getX(), (int) rec9.getY(),
                (int) rec9.getWidth(), (int) rec9.getHeight());
    } else {
        rec1 = new Rectangle(10, 130, 50, 50);
        g.fillRect((int) rec1.getX(), (int) rec1.getY(),
                (int) rec1.getWidth(), (int) rec1.getHeight());
        rec2 = new Rectangle(70, 130, 50, 50);
        g.fillRect((int) rec2.getX(), (int) rec2.getY(),
                (int) rec2.getWidth(), (int) rec2.getHeight());
        rec3 = new Rectangle(130, 130, 50, 50);
        g.fillRect((int) rec3.getX(), (int) rec3.getY(),
                (int) rec3.getWidth(), (int) rec3.getHeight());
        rec4 = new Rectangle(10, 70, 50, 50);
        g.fillRect((int) rec4.getX(), (int) rec4.getY(),
                (int) rec4.getWidth(), (int) rec4.getHeight());
        rec5 = new Rectangle(70, 70, 50, 50);
        g.fillRect((int) rec5.getX(), (int) rec5.getY(),
                (int) rec5.getWidth(), (int) rec5.getHeight());
        rec6 = new Rectangle(130, 70, 50, 50);
        g.fillRect((int) rec6.getX(), (int) rec6.getY(),
                (int) rec6.getWidth(), (int) rec6.getHeight());
        rec7 = new Rectangle(10, 10, 50, 50);
        g.fillRect((int) rec7.getX(), (int) rec7.getY(),
                (int) rec7.getWidth(), (int) rec7.getHeight());
        rec8 = new Rectangle(70, 10, 50, 50);
        g.fillRect((int) rec8.getX(), (int) rec8.getY(),
                (int) rec8.getWidth(), (int) rec8.getHeight());
        g.setColor(Color.LIGHT_GRAY);
        rec9 = new Rectangle(130, 10, 50, 50);
        g.fillRect((int) rec9.getX(), (int) rec9.getY(),
                (int) rec9.getWidth(), (int) rec9.getHeight());
    }

}

新代码::

private static void drawRectangle(Graphics g, int column, int row,
        Color color) {
    g.setColor(color);
    g.fillRect(column * 60 + 10, row * 60 + 10, 50, 50);
    n = rand.nextInt(9);
    for (row = 0; row < 3; row++) {
        for (column = 0; column < 3; column++) {
            drawRectangle(g, column, row,
                    n == row * 3 + column ? Color.LIGHT_GRAY
                            : Color.DARK_GRAY);
        }
    }
}

Answer 1

我首先要写一个辅助方法：

private static void drawRectangle(Graphics g, int column, int row, Color color) {
    // TODO: Remember the previous color of g and reset it afterwards?
    g.setColor(color);
    g.fillRect(column * 60 + 10, row * 60 + 10, 50, 50);
}

然后在需要绘制矩形的代码中（例如，问题中的代码所在的位置）使用嵌套循环绘制所有9个矩形，根据n的值计算每个矩形的颜色：

// It's simpler to use n being 0 to 8, if that's okay with the rest of your code.
n = rand.nextInt(9);
for (int row = 0; row < 3; row++) {
    for (int column = 0; column < 3; column++) {
        drawRectangle(g, column, row,
            n == row * 3 + column ? Color.LIGHT_GRAY : Color.DARK_GRAY);
    }
}

假设您根本不需要Rectangle个对象。如果您这样做，则需要更改drawRectangle方法以创建并返回Rectangle，然后设置Rectangle[]，List<Rectangle>或可能Rectangle[][]取决于你想用它们做什么。我强烈建议您不只有9个单独的变量。