c# - 如何在我的 WinForms 应用程序中制作同心圆图案？

Question

我在尝试将圆圈变成同心图案时遇到了麻烦。例如，下一个圆圈更大，然后更大等等。有点像地核、内核、外核和地壳。

以下是我的所有代码：

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);
        }
    }
}

Answer 1

您需要在类上定义大小变量，以便可以在连续点击时使用它。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
        }
    }
}