4C/GummingCommon/Controls/Radar.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Design;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.Drawing.Text;
using System.Windows.Forms;
using System.Linq;

namespace GummingCommon
{
    public class Radar
    {
        private double scale;
        private float fixedvalue = 0;
        public Bitmap DrawRegularPolygon(int width, int height, int angle, float[] dots, string[] names)
        {
            fixedvalue = 0;
            Array.Reverse(names);//翻转后才可以和数据匹配上
            int sides = dots.Length;
            int margin = 30;
            int radius = width / 2 - margin;
            int space = radius / 6;
            float minvalue = dots.Min();
            if (minvalue < 0)
            {
                fixedvalue = Math.Abs(minvalue) + 1;
                scale = radius * 1.0 / (dots.Max() + fixedvalue);
                for (int i = 0; i < dots.Length; i++)
                {
                    dots[i] = dots[i] + fixedvalue;
                }
            }
            else
            {
                scale = radius * 1.0 / dots.Max();
            }
            Point center = new Point(width / 2, height / 2);

            //Render the polygon
            Bitmap polygon = new Bitmap(width, width);
            using (Graphics g = Graphics.FromImage(polygon))
            {
                g.Clear(Color.FromArgb(255, 255, 255));
                int spaces = space;
                int steps = radius / space;
                for (int i = 0; i < steps; i++)
                {
                    Point[] verticies = CalculateVertices(sides, spaces, angle, center);

                    g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
                    g.DrawPolygon(new Pen(Color.FromArgb(200, 200, 200), 1), verticies);


                    g.DrawString(Math.Round(spaces / scale - fixedvalue, 2).ToString(), SystemFonts.DefaultFont, Brushes.Black, new Point() { X = verticies[verticies.Length - 1].X, Y = verticies[verticies.Length - 1].Y });

                    //g.DrawRectangle(new Pen(Color.FromArgb(220, 220, 220), 1), new Rectangle(center, new Size(1, 1)));

                    //foreach (var point in verticies)
                    //{
                    //    g.DrawLine(new Pen(Color.FromArgb(220, 220, 220), 1), center, point);
                    //}
                    spaces = spaces + space;

                    if (i == steps - 1)
                    {
                        for (int j = 0; j < verticies.Length; j++)
                        {
                            int x = verticies[j].X;
                            int y = verticies[j].Y;
                            if (j == 0) { x = x - 20; } //左上角
                            if (j == 1) { x = x - 20; } //左下角
                            if (j == 2) { x = x + 20; } //右下角
                            if (j == 3) { x = x + 20; }//右上角
                            if (j == 4) { y = y - 20; }//上角
                            g.DrawString(names[j], SystemFonts.DefaultFont, Brushes.Black, new Point() { X = x, Y = y }, new StringFormat() { Alignment = StringAlignment.Center });
                        }
                    }
                }

                //Get the location for each vertex of the polygon
                Point[] exportdots = CalculateVertices(sides, radius, angle, center, dots);
                g.DrawPolygon(new Pen(Color.FromArgb(50, 205, 50), 1), exportdots);
            }

            return polygon;
        }

        private Point[] CalculateVertices(int sides, int radius, int startingAngle, Point center)
        {
            if (sides < 3)
                throw new ArgumentException("at least 3 points.");

            List<Point> points = new List<Point>();
            float step = 360.0f / sides;

            float angle = startingAngle;
            for (int i = 0; i < sides; i++)
            {
                points.Add(DegreesToXY(angle, radius, center));
                angle += step;
            }
            return points.ToArray();
        }

        private Point[] CalculateVertices(int sides, int radius, int startingAngle, Point center, float[] dots)
        {
            if (sides < 3)
                throw new ArgumentException("at least 3 points.");

            List<Point> points = new List<Point>();
            float step = 360.0f / sides;

            float angle = startingAngle;
            for (int i = 0; i < sides; i++)
            {
                points.Add(DegreesToXY(angle, dots[sides - i - 1] * scale, center));
                angle += step;
            }

            return points.ToArray();
        }

        private Point DegreesToXY(float degrees, double radius, Point origin)
        {
            Point xy = new Point();
            double radians = degrees * Math.PI / 180.0;

            xy.X = (int)(Math.Cos(radians) * radius + origin.X);
            xy.Y = (int)(Math.Sin(-radians) * radius + origin.Y);

            return xy;
        }
    }

}