C# 如何在WinForms应用程序中创建同心圆图案？

我很难把这些圆做成同心的形状。例如，下一个圆越大，然后越大，依此类推。有点像地核、地核、地核和地壳

以下是我的全部代码：

namespace ClickAppearBalls
{
    public partial class Form1 : Form
    {
        private Random randClick;
        private Graphics paper;
        private Pen pen;
        public Form1()
        {
            InitializeComponent();
            randClick = new Random();
            paper = picCanvas.CreateGraphics();

        }

        private void picCanvas_Click(object sender, EventArgs e)
        {
            int x, y, size1, size2;

            x = picCanvas.Height / 2;
            y = picCanvas.Width / 2;

            Color color = Color.FromArgb(randClick.Next(0, 256), randClick.Next(0, 256), randClick.Next(0, 256));
            Pen pen = new Pen(color);
            pen.Width = 3;
            size1 = 30;
            size2 = 30;
            paper.DrawEllipse(pen, x, y, size1, size2);
        }
    }
}

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您需要在类上定义size变量，以便在连续单击时使用它。然后你需要在每次点击时增加它

namespace ClickAppearBalls
{
    public partial class Form1 : Form
    {
        private Random randClick;
        private Graphics paper;
        private Pen pen;
        private int circleSize = 30;

        public Form1()
        {
            InitializeComponent();
            randClick = new Random();
            paper = picCanvas.CreateGraphics();

        }

        private void picCanvas_Click(object sender, EventArgs e)
        {
            int x, y;

            x = picCanvas.Height / 2;
            y = picCanvas.Width / 2;

            Color color = Color.FromArgb(randClick.Next(0, 256), randClick.Next(0, 256), randClick.Next(0, 256));
            Pen pen = new Pen(color);
            pen.Width = 3;
            paper.DrawEllipse(pen, x - circleSize/2, y - circleSize/2, circleSize, circleSize);

            circleSize += 10; // increase size here
        }
    }
}

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实际上，你需要从外面开始收缩，因为新层将覆盖旧层，所以如果你想看到两层（或重新绘制内层），新层必须更小。@ScottChamberlain否，因为圆圈没有填充。我检查过了，它是有效的，虽然我还必须移动圆圈的中间点。对，我在想一个不同的函数。上面的建议是有效的，但是圆圈看起来好像点击了右下角，我怎么能让它在中间扩展，而不会重叠任何想法。谢谢你，盖伊。我几分钟前就修好了。需要将

x-circleSize/2、y-circleSize/2

作为圆的中点。