Hello all,

I set up Visual Studio 2017 for OpenGL and ran this and this codes successfully.

I get these linker errors when compiling the following code:

#include <iostream>
using namespace std;
#include "vgl.h"
#include "LoadShaders.h"

enum VAO_IDs { Triangles, NumVAOs };
enum Buffer_IDs { ArrayBuffer, NumBuffers };
enum Attrib_IDs { vPosition = 0 };
GLuint VAOs[NumVAOs];
GLuint Buffers[NumBuffers];
const GLuint NumVertices = 6;
//--------------------------------------------------------------------
//
// init
//
void
init(void)
{
    static const GLfloat vertices[NumVertices][2] =
    {
        { -0.90, -0.90 }, // Triangle 1
        { 0.85, -0.90 },
        { -0.90, 0.85 },
        { 0.90, -0.85 }, // Triangle 2
        { 0.90, 0.90 },
        { -0.85, 0.90 }
    };
    glCreateBuffers(NumBuffers, Buffers);
    glNamedBufferStorage(Buffers[ArrayBuffer], sizeof(vertices),
        vertices, 0);
    ShaderInfo shaders[] = {
        { GL_VERTEX_SHADER, "triangles.vert" },
        { GL_FRAGMENT_SHADER, "triangles.frag" },
        { GL_NONE, NULL }
    };
    GLuint program = LoadShaders(shaders);
    glUseProgram(program);
    glGenVertexArrays(NumVAOs, VAOs);
    glBindVertexArray(VAOs[Triangles]);
    glBindBuffer(GL_ARRAY_BUFFER, Buffers[ArrayBuffer]);
    glVertexAttribPointer(vPosition, 2, GL_FLOAT,
        GL_FALSE, 0, BUFFER_OFFSET(0));
    glEnableVertexAttribArray(vPosition);
}
//--------------------------------------------------------------------
//
// display
//
void
display(void)
{
    static const float black[] = { 0.0f, 0.0f, 0.0f, 0.0f };
    glClearBufferfv(GL_COLOR, 0, black);
    glBindVertexArray(VAOs[Triangles]);
    glDrawArrays(GL_TRIANGLES, 0, NumVertices);
}
//--------------------------------------------------------------------
//
// main
//
int
main(int argc, char** argv)
{
    glfwInit();
    GLFWwindow* window = glfwCreateWindow(640, 480, "Triangles", NULL,
        NULL);
    glfwMakeContextCurrent(window);
    gl3wInit();
    init();

    while (!glfwWindowShouldClose(window))
    {
        display();
        glfwSwapBuffers(window);
        glfwPollEvents();
    }

    glfwDestroyWindow(window);
    glfwTerminate();
}

Is there any way to solve this issue?

looks to me like you are trying to use GL3W now after trying out GLAD and didn't swap out the c files. 

edit: Just now, I've upgraded opengl function pointer loading from GLEW to GL3W in my personal framework. Took a touch of google to help with the transition, but the experience was satisfying. Worth the effort? pfffttt...but its done.