即使您创建了VBO和VAO并填充了它们，但您没有正确使用它们。

您首先需要绑定VAO，然后绑定VBO，然后将数据复制到缓冲区，并使用glVertex AttribPointer()函数，然后解除两个缓冲区的绑定。

然后在渲染之前，再次绑定Vao，并在绘制后解除绑定。

您还需要着色器

我在您的代码中没有看到任何着色器。

以下是一个有效的代码：

# include <iostream>

// GLEW

# define GLEW_STATIC

# include <GL/glew.h>

// GLFW

# include <GLFW/glfw3.h>

// Function prototypes
void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode);

// Window dimensions
const GLuint WIDTH = 800, HEIGHT = 600;

// Shaders
const GLchar* vertexShaderSource = "#version 330 coren"
"layout (location = 0) in vec3 position;n"
"void main()n"
"{n"
"gl_Position = vec4(position.x, position.y, position.z, 1.0);n"
"}0";
const GLchar* fragmentShaderSource = "#version 330 coren"
"out vec4 color;n"
"void main()n"
"{n"
"color = vec4(1.0f, 0.5f, 0.2f, 1.0f);n"
"}n0";

// The MAIN function, from here we start the application and run the game loop
int main()
{
// Init GLFW
glfwInit();
// Set all the required options for GLFW
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
glfwWindowHint(GLFW_RESIZABLE, GL_FALSE);

// Create a GLFWwindow object that we can use for GLFW's functions
GLFWwindow* window = glfwCreateWindow(WIDTH, HEIGHT, "LearnOpenGL", nullptr, nullptr);
glfwMakeContextCurrent(window);

// Set the required callback functions
glfwSetKeyCallback(window, key_callback);

// Set this to true so GLEW knows to use a modern approach to retrieving function pointers and extensions
glewExperimental = GL_TRUE;
// Initialize GLEW to setup the OpenGL Function pointers
glewInit();

// Define the viewport dimensions
int width, height;
glfwGetFramebufferSize(window, &width, &height);  
glViewport(0, 0, width, height);

// Build and compile our shader program
// Vertex shader
GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
glCompileShader(vertexShader);
// Check for compile time errors
GLint success;
GLchar infoLog[512];
glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
if (!success)
{
    glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
    std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILEDn" << infoLog << std::endl;
}
// Fragment shader
GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
glCompileShader(fragmentShader);
// Check for compile time errors
glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
if (!success)
{
    glGetShaderInfoLog(fragmentShader, 512, NULL, infoLog);
    std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILEDn" << infoLog << std::endl;
}
// Link shaders
GLuint shaderProgram = glCreateProgram();
glAttachShader(shaderProgram, vertexShader);
glAttachShader(shaderProgram, fragmentShader);
glLinkProgram(shaderProgram);
// Check for linking errors
glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
if (!success) {
    glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);
    std::cout << "ERROR::SHADER::PROGRAM::LINKING_FAILEDn" << infoLog << std::endl;
}
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);

// Set up vertex data (and buffer(s)) and attribute pointers
GLfloat vertices[] = {
    -0.5f, -0.5f, 0.0f, // Left  
     0.5f, -0.5f, 0.0f, // Right 
     0.0f,  0.5f, 0.0f  // Top   
};
GLuint VBO, VAO;
glGenVertexArrays(1, &VAO);
glGenBuffers(1, &VBO);
// Bind the Vertex Array Object first, then bind and set vertex buffer(s) and attribute pointer(s).
glBindVertexArray(VAO);

glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(GLfloat), (GLvoid*)0);
glEnableVertexAttribArray(0);

glBindBuffer(GL_ARRAY_BUFFER, 0); // Note that this is allowed, the call to glVertexAttribPointer registered VBO as the currently bound vertex buffer object so afterwards we can safely unbind

glBindVertexArray(0); // Unbind VAO (it's always a good thing to unbind any buffer/array to prevent strange bugs)

// Game loop
while (!glfwWindowShouldClose(window))
{
    // Check if any events have been activiated (key pressed, mouse moved etc.) and call corresponding response functions
    glfwPollEvents();

    // Render
    // Clear the colorbuffer
    glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT);

    // Draw our first triangle
    glUseProgram(shaderProgram);
    glBindVertexArray(VAO);
    glDrawArrays(GL_TRIANGLES, 0, 3);
    glBindVertexArray(0);

    // Swap the screen buffers
    glfwSwapBuffers(window);
}
// Properly de-allocate all resources once they've outlived their purpose
glDeleteVertexArrays(1, &VAO);
glDeleteBuffers(1, &VBO);
// Terminate GLFW, clearing any resources allocated by GLFW.
glfwTerminate();
return 0;
}

// Is called whenever a key is pressed/released via GLFW
void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode)
{
if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
    glfwSetWindowShouldClose(window, GL_TRUE);
}

来源：https://learnopengl.com/code_viewer.php?code=getting-started/hellotriangle

我建议你从一开始就学习OpenGL。https://learnopengl.com/是学习OpenGL的好地方。

You have绘制->清除->交换。

在你画画之前清除，而不是在之后：

while (!glfwWindowShouldClose(window))
{
    glfwPollEvents();
    if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
    {
        glfwSetWindowShouldClose(window, GL_TRUE);
    }

    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT);

    glViewport(0, 0, width, height);
    glDrawArrays(GL_TRIANGLES, 0, 3);

    glfwSwapBuffers(window);
}