C＃OutofrangeException应该是不可能的

Question

我有一些代码（如下所示），该代码在不同的线程上运行，并在其他任何可能在此处干扰它的地方都没有引用变量 i 。我只是不明白导致此错误的情况，我将一些观察者放在视觉工作室代码上，并且这些值似乎都很好，但几乎随机地无处可获得这个错误。

尽管我最好的知识完全与之隔绝了，但这是否可能是由代码的另一部分引起的？我什至将 i 的所有其他用途重命名为不同的字母，但我仍然遇到了这个问题。

这只是 for loops 的东西吗？

我是否以某种方式修改 i 甚至不知道吗？

这是完整的代码：

using SFML.Graphics;
using SFML.Window;
using System.Diagnostics;
using System.Numerics;

namespace RenderEngine
{
    public class Program
    {

        /// <summary>
        ///  The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            PhysicsEngine re = new PhysicsEngine();
            for (int i = 0; i < 100; i++)
            {
                Debug.WriteLine(i);
            }

        }
    }
    public class PhysicsEngine
    {
        Solver solver = new Solver();
        public void RenderEngine2()
        {
            ContextSettings settings = new ContextSettings();
            settings.AntialiasingLevel = 8;
            RenderWindow window = new RenderWindow(new VideoMode(2000, 1000), "Poop", Styles.Default, settings);
            SFML.Graphics.Color color = new SFML.Graphics.Color(0, 0, 0, 0);
            window.SetVerticalSyncEnabled(true);
            CircleShape shape = new CircleShape(5);
            shape.FillColor = new SFML.Graphics.Color(0, 0, 255, 255);
            window.Closed += handelclose;
            int drawcount = 0;
            while (window.IsOpen)
            {
                window.Clear(color);
                window.DispatchEvents();
                try
                {
                    foreach (Partical partical in solver.Particals)
                    {
                        shape.Position = new SFML.System.Vector2f((partical.position.X), (partical.position.Y));
                        window.Draw(shape);
                        drawcount++;
                    }
                    drawcount = 0;
                }
                catch
                {
                    Debug.WriteLine("notready yet");
                }

                window.Display();

            }
            void handelclose(object sender, EventArgs e)
            {
                window.Close();
                Environment.Exit(Environment.ExitCode);
            }
        }
        List<Partical> todraw = new List<Partical>();
        void EngineLoop()
        {
            while (true)
            {
                foreach (Partical partical in solver.Particals)
                {
                    int x = (int)Math.Round(partical.position.X/10);
                    int y = (int)Math.Round(partical.position.Y/10);
                    List<int> ts = solver.Grid[x, y];
                    if (ts != null)
                    {
                        for (int brokenint = 0; brokenint < ts.Count; brokenint++)
                        {
                            Debug.WriteLine(partical.ID);
                            Debug.WriteLine(ts[brokenint]);
                            if (partical.ID != ts[brokenint])
                            {
                                
                                Vector2 pos = new Vector2(partical.ID, ts[brokenint]);
                                if (solver.Collision.Count > 0)
                                {
                                    if (!solver.Collision.Contains(pos))
                                        solver.Collision.Add(pos);
                                }
                                else
                                {
                                    solver.Collision.Add(pos);
                                }
                            }
                        }
                    }
                }
            }
        }
        private int particalcount = 10;
        bool canstart = false;
        public PhysicsEngine()
        {
            Parallel.Invoke(() =>
            {
                while (!canstart) { Thread.Sleep(100); }
                Debug.WriteLine("third thread");
                RenderEngine2();

            },
            () =>
            {
                while (!canstart) { Thread.Sleep(100); }
                Debug.WriteLine("engine started");
                EngineLoop();
            },
            () =>
            {
                Debug.WriteLine("first thread");
                PhysicsLoop(this);
            }
            );
        }
        void PhysicsLoop(PhysicsEngine PhyEng)
        {
            int frames = 0;
            long second = 0;
            PhysicsStart(PhyEng);
            Thread.Sleep(1000);
            Stopwatch sw = Stopwatch.StartNew();
            solver.startupdate();
            while (true)
            {
                sw.Start();
                todraw = solver.Particals;
                solver.update();
                frames++;
                if (second != (Stopwatch.GetTimestamp() / Stopwatch.Frequency))
                {
                    second = (Stopwatch.GetTimestamp() / Stopwatch.Frequency);
                    Debug.WriteLine(frames);
                    frames = 0;
                }
                sw.Stop();
                sw.Reset();
                if (sw.ElapsedMilliseconds < 15)
                    Thread.Sleep(15 - (int)sw.ElapsedMilliseconds);
            }
        }
        void PhysicsStart(PhysicsEngine phyeng)
        {
            for (int i = 0; i < 210; i++)
            {
                for (int j = 0; j < 110; j++)
                {
                    solver.Grid[i,j] = new List<int>();
                }
            }

            Random rand = new Random();
            for (int i = 0; i < particalcount; i++)
            {
                Partical partical = new Partical();
                partical.position = new Vector2(rand.Next(0, 2000), rand.Next(0, 1000));
                partical.oldposition = partical.position;
                partical.ID = i;
                int x1 = (int)Math.Round((partical.position.X + 5) / 10);
                int y1 = (int)Math.Round((partical.position.Y + 5) / 10);
                int x2 = (int)Math.Round((partical.position.X - 5) / 10);
                int y2 = (int)Math.Round((partical.position.Y - 5) / 10);
                solver.Grid[x1, y1].Add(partical.ID);
                solver.Grid[x2, y1].Add(partical.ID);
                solver.Grid[x1, y2].Add(partical.ID);
                solver.Grid[x2, y2].Add(partical.ID);
                solver.Particals.Add(partical);
            }
            canstart = true;
        }
    }
    public class Partical
    {
        public Vector2 position = new Vector2(0, 0);
        public Vector2 oldposition = new Vector2(0, 0);
        public Vector2 acceleration = new Vector2(0, 0);
        Vector2 zero = new Vector2(0, 0);
        public int ID = new int();

        public void updatePosition(float sub)
        {
            Vector2 velocity = position - oldposition;
            oldposition = position;
            position = position + (velocity * 0.9f) + acceleration * sub;
            acceleration = zero;
        }
        public void accelerate(Vector2 accel)
        {
            acceleration = acceleration + accel;
        }
    }

    public class Solver
    {
        public List<Partical> Particals = new List<Partical>();
        public List<Vector2> Collision = new List<Vector2>();
        public List<int>[,] Grid = new List<int>[2100,1100];
        public void update()
        {
            int subcount = 8;
            float sub = 1f / (float)subcount;
            for (int i = 0; i < subcount; i++)
            {
                applyGravity(sub);
                updatePositions(sub);
                for (int j = 0; j < Collision.Count; j++)
                {
                    solvecolisions((int)Collision[j].X, (int)Collision[j].Y);
                }
                Collision.Clear();
            }
        }
        public void startupdate()
        {
            applyGravity(0.5f);
            updatePositions(0.5f);
            applyGravity(0.5f);
            updatePositions(0.5f);
        }
        void updatePositions(float sub)
        {
            foreach (Partical partical in Particals)
            {
                partical.updatePosition(sub);
                    int x1 = (int)Math.Round((partical.oldposition.X + 5) / 10);
                    int y1 = (int)Math.Round((partical.oldposition.Y + 5) / 10);
                    int x2 = (int)Math.Round((partical.oldposition.X - 5) / 10);
                    int y2 = (int)Math.Round((partical.oldposition.Y - 5) / 10);
                    Grid[x1,y1].Remove(partical.ID);
                    Grid[x2,y1].Remove(partical.ID);
                    Grid[x1,y2].Remove(partical.ID);
                    Grid[x2,y2].Remove(partical.ID);                    
                    x1 = (int)Math.Round((partical.position.X + 5) / 10);
                    y1 = (int)Math.Round((partical.position.Y + 5) / 10);
                    x2 = (int)Math.Round((partical.position.X - 5) / 10);
                    y2 = (int)Math.Round((partical.position.Y - 5) / 10);
                    Grid[x1,y1].Add(partical.ID);
                    Grid[x2,y1].Add(partical.ID);
                    Grid[x1,y2].Add(partical.ID);
                    Grid[x2,y2].Add(partical.ID);
            }
        }
        void applyGravity(float sub)
        {
            float gravitystrangth = -0.1f;
            foreach (Partical partical in Particals)
            {
                float a = partical.position.Y;
                float b = partical.position.X;
                b -= 1000;
                a -= 500;
                double angle = Math.Atan2(a, b);
                float newA = gravitystrangth * (float)(Math.Sin(angle));
                float newB = gravitystrangth * (float)(Math.Sin((Math.PI / 180) * 90 - angle));
                Vector2 gravity = new Vector2(newB, newA);
                partical.accelerate(gravity);
            }
        }
        void solvecolisions(int id1, int id2)
        {
            Partical part = Particals[id1];
            Partical part2 = Particals[id2];
            if (part != part2)
            {
                Vector2 colisionaxis = part.position - part2.position;
                float dist = colisionaxis.Length();
                if (dist < 10)
                {
                    Vector2 n = colisionaxis / dist;
                    float delta = 10 - dist;
                    part.position += 0.5f * delta * n;
                    part2.position -= 0.5f * delta * n;
                }
            }
        }
        public List<Partical> GetParticals()
        {
            return Particals;
        }
    }
}

Answer 1

您的ts列表取决于solver.grid [x，y]。我相信您的某些代码在屏幕上不可见会更改solver.grid，可能有时会删除或替换它们。这就是导致错误的原因。