Question

我是学生在学校学习C＃并在我们的图形单元中有一个项目。我使用点创建了一个圣诞树并将其填入。现在我正在寻找在我已经在树中声明的范围内创建椭圆饰品。有没有办法只在我的树中制作这些椭圆，并让它们根据树中的随机数生成器进行更改？谢谢。

这是我的树代码。我制作的椭圆是雪花。 SolidBrush green = new SolidBrush（Color.Green）;

    Pen greentree = new Pen(Color.Green);

    Point[] christmastree = new Point[11];
    christmastree[0] = new Point(518, 400);
    christmastree[1] = new Point(620, 300);
    christmastree[2] = new Point(549, 300);
    christmastree[3] = new Point(645, 185);
    christmastree[4] = new Point(607, 185);
    christmastree[5] = new Point(673, 102);
    christmastree[6] = new Point(744, 185);
    christmastree[7] = new Point(706, 185);
    christmastree[8] = new Point(793, 300);
    christmastree[9] = new Point(720, 300);
    christmastree[10] = new Point(835, 400);
    g.DrawPolygon(greentree, christmastree);
    g.FillPolygon(green, christmastree);

    //Snow
    Random r = new Random();
    SolidBrush snowsb = new SolidBrush(Color.White);
    for(int i = 1; i <= 40; i++)
    {
        int snowflake_x = r.Next(1000);
        int snowflake_y = r.Next(500);
        g.FillEllipse(snowsb, snowflake_x, snowflake_y, 4,4);
    }

就像我说的那样，我在这个C＃领域缺乏经验。谢谢

Answer 1

尝试类似的东西：

Random r = new Random();

// Number of ellipses
int ellipseCount = 0;

// Loop for setting a specified amount of ellipses
while (ellipseCount < 10)
{

    // New random point 
    Point p = new Point(r.Next(0, 300), r.Next(0,300));
    // check if point is in my range
    if (p.IsInMyRange())
    {
         Ellipse e = new Ellipse {Width = 10, Height = 10};
         // Implement: set coordinates to ellipse

         ellipseCount++;
    }
}

您需要实施一种方法来测试您的点是否在您的范围内。没有你的代码，我无法帮助你。

Answer 2

试试这个......

namespace Baum
{
    using System;
    using System.Drawing;
    using System.Drawing.Drawing2D;
    using System.Windows.Forms;

    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e);

            e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;

            PointF[] tree = new PointF[]
            {
                new PointF(12, 0),
                new PointF(16, 4),
                new PointF(13, 4),
                new PointF(19, 11),
                new PointF(13, 11),
                new PointF(21, 20),
                new PointF(3, 20),
                new PointF(11, 11),
                new PointF(5, 11),
                new PointF(11, 4),
                new PointF(8, 4)
            };

            PointF[] stump = new PointF[]
            {
                new PointF(10, 20),
                new PointF(14, 20),
                new PointF(14, 27),
                new PointF(19, 27),
                new PointF(19, 30),
                new PointF(6, 30),
                new PointF(6, 27),
                new PointF(10, 27)
            };

            using (GraphicsPath path = new GraphicsPath())
            {
                path.AddPolygon(tree);
                Matrix m = new Matrix();
                m.Scale(20, 20);
                path.Transform(m);
                e.Graphics.FillPath(Brushes.Green, path);

                foreach (PointF p in path.PathPoints)
                {
                    int s = 15;
                    PointF q = p;
                    q.X -= (s / 2);
                    q.Y -= (s / 2);

                    if (new Random(Guid.NewGuid().GetHashCode()).Next(0, tree.Length) > tree.Length / 2)
                    {
                        e.Graphics.FillEllipse(Brushes.Red, new RectangleF(q.X, q.Y, s, s));
                    }
                }
            }

            using (GraphicsPath path = new GraphicsPath())
            {
                path.AddPolygon(stump);
                Matrix m = new Matrix();
                m.Scale(20, 20);
                path.Transform(m);
                e.Graphics.FillPath(Brushes.Brown, path);
            }

            System.Threading.Thread.Sleep(500);
            Refresh();

        }

        private void button1_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }
    }
}

如何在设定范围内的随机点绘制椭圆？

2 个答案: