ColoredTriangleVaoOpenTK4OpenGL31 (Added shaders to Program.cs)

Program.cs

using OpenToolkit.Graphics.OpenGL;
using OpenToolkit.Windowing.Desktop;
using OpenToolkit.Mathematics;
using System.IO;
using System;

namespace ColoredTriangleVaoOpenTK4OpenGL31
{
    class Program
    {
        static void Main(string[] args)
        {
            GameWindowSettings gameWindowSettings = new GameWindowSettings();

            NativeWindowSettings nativeWindow = new NativeWindowSettings();
            nativeWindow.Size = new Vector2i(270, 270);

            nativeWindow.APIVersion = System.Version.Parse("3.1");
            nativeWindow.Profile = OpenToolkit.Windowing.Common.ContextProfile.Any;

            using (var window = new Window(gameWindowSettings, nativeWindow))
            {
                window.Run();
            }
        }
    }

    class Window : GameWindow
    {
        private int _program;
        // private int _vao;

        public Window(GameWindowSettings gameWindowSettings, NativeWindowSettings nativeWindow)
            : base(gameWindowSettings, nativeWindow)
        {

        }

        protected override void OnLoad()
        {
            Title = "Colored Triangle";
            GL.ClearColor(0f, 0.1f, 0.2f, 1f);

            _program = LoadShaders();

            float[] positions = new float[] {
                0f, 1f, 0f,
                -1f, 0f, 0f,
                1f, 0f, 0f
            };

            float[] colors = new float[] {
                1f, 0f, 0f,
                1f, 0f, 0f,
                1f, 0f, 0f
            };

            // int vao = GL.GenVertexArray();
            // GL.GenVertexArrays(1, out _vao);
            // GL.BindVertexArray(_vao);

            int vboPos;
            GL.GenBuffers(1, out vboPos);
            GL.BindBuffer(BufferTarget.ArrayBuffer, vboPos);
            GL.BufferData(BufferTarget.ArrayBuffer, sizeof(float) * positions.Length,
                          positions, BufferUsageHint.StaticDraw);

            int aPositionLoc = GL.GetAttribLocation(_program, "aPosition");
            GL.VertexAttribPointer(aPositionLoc, 3, VertexAttribPointerType.Float, false, 0, 0);
            GL.EnableVertexAttribArray(aPositionLoc);

            int vboColor;
            GL.GenBuffers(1, out vboColor);
            GL.BindBuffer(BufferTarget.ArrayBuffer, vboColor);
            GL.BufferData(BufferTarget.ArrayBuffer, sizeof(float) * colors.Length,
                          colors, BufferUsageHint.StaticDraw);

            int aColorLoc = GL.GetAttribLocation(_program, "aColor");
            GL.VertexAttribPointer(aColorLoc, 3, VertexAttribPointerType.Float, false, 0, 0);
            GL.EnableVertexAttribArray(aColorLoc);

            // GL.BindVertexArray(0);
            // GL.BindBuffer(BufferTarget.ArrayBuffer, 0);
        }

        protected override void OnRenderFrame(OpenToolkit.Windowing.Common.FrameEventArgs args)
        {
            GL.Clear(ClearBufferMask.ColorBufferBit);
            // GL.BindVertexArray(_vao);
            GL.DrawArrays(OpenToolkit.Graphics.OpenGL.PrimitiveType.Triangles, 0, 3);
            SwapBuffers();
        }

        private static int LoadShaders()
        {
            int vShader = GL.CreateShader(ShaderType.VertexShader);
            int fShader = GL.CreateShader(ShaderType.FragmentShader);

            #region Vertex Shader Loading
            // string source = File.ReadAllText("Shaders/vShader.glsl");
            string vSource = string.Join(
                Environment.NewLine,
                "#version 140",
                "in vec3 aPosition;",
                "in vec3 aColor;",
                "out vec3 vColor;",
                "void main()",
                "{",
                "    gl_Position = vec4(aPosition, 1.0);",
                "    vColor = aColor;",
                "}");
            GL.ShaderSource(vShader, vSource);
            GL.CompileShader(vShader);

            int status;
            GL.GetShader(vShader, ShaderParameter.CompileStatus, out status);

            if (status == 0)
            {
                string info = GL.GetShaderInfoLog(vShader);
                Console.WriteLine("Vertex Shader Error: " + info);
                // return -1;
            }
            #endregion

            #region Fragment Shader Loading
            // source = File.ReadAllText("Shaders/fShader.glsl");
            string fSource = string.Join(
                Environment.NewLine,
                "#version 140",
                "in vec3 vColor;",
                "out vec4 fragColor;",
                "void main()",
                "{",
                "    fragColor = vec4(vColor, 1.0);",
                "}");
            GL.ShaderSource(fShader, fSource);
            GL.CompileShader(fShader);

            GL.GetShader(fShader, ShaderParameter.CompileStatus, out status);

            if (status == 0)
            {
                string info = GL.GetShaderInfoLog(fShader);
                Console.WriteLine("Fragment Shader Error: " + info);
                // return -1;
            }
            #endregion

            #region Creating Shader Program
            int program = GL.CreateProgram();
            GL.AttachShader(program, vShader);
            GL.AttachShader(program, fShader);
            GL.LinkProgram(program);

            GL.GetProgram(program, GetProgramParameterName.LinkStatus, out status);
            if (status == 0)
            {
                string info = GL.GetProgramInfoLog(program);
                Console.WriteLine("Program Error: " + info);
                // return -1;
            }
            #endregion

            GL.UseProgram(program);
            // GL.DeleteShader(vShader);
            // GL.DeleteShader(fShader);

            return program;
        }
    }
}