数据：
float vertices[] = {
0.5f, 0.5f, 0.0f, // top right
0.5f, -0.5f, 0.0f, // bottom right
-0.5f, -0.5f, 0.0f, // bottom left
-0.5f, 0.5f, 0.0f // top left
};
unsigned int indices[] = { // note that we start from 0!
0, 1, 3, // first triangle
1, 2, 3 // second triangle
};
initializeGL()函数：

	initializeOpenGLFunctions();
    //创建VBO和VAO对象，并赋予ID
    glGenVertexArrays(1, &VAO);
    glGenBuffers(1, &VBO);
    //绑定VBO和VAO对象
    glBindVertexArray(VAO);
    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    //为当前绑定到target的缓冲区对象创建一个新的数据存储。
    //如果data不是NULL，则使用来自此指针的数据初始化数据存储
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
    //告知显卡如何解析缓冲里的属性值
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
    //开启VAO管理的第一个属性值
    glEnableVertexAttribArray(0);
    glBindBuffer(GL_ARRAY_BUFFER, 0);
    bool success;
    shaderProgram.addShaderFromSourceFile(QOpenGLShader::Vertex, "shaders/shapes.vert");
    shaderProgram.addShaderFromSourceFile(QOpenGLShader::Fragment, "shaders/shapes.frag");
    success = shaderProgram.link();
    if (!success)
        qDebug() << "ERR:" << shaderProgram.log();
    glGenBuffers(1, &EBO);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
    glBindVertexArray(0);

paintGL()函数：

	glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT);
    shaderProgram.bind();
    glBindVertexArray(VAO);
    glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, NULL);

resizeGL(int w, int h)函数：

	Q_UNUSED(w); Q_UNUSED(h);

析构函数：

makeCurrent();
    glDeleteBuffers(1, &VBO);
    glDeleteBuffers(1, &EBO);
    glDeleteVertexArrays(1, &VAO);
    doneCurrent();

顶点着色器代码(shapes.vert)：

#version 330 core
layout(location = 0) in vec3 aPos;
out vec4 vertexColor;
void main(){
    gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0f);
    vertexColor=vec4(0.5, 0.0, 0.0, 1.0);
}

片段着色器代码(shapes.frag)：

#version 330 core
out vec4 FragColor;
in vec4 vertexColor;
void main(){
    FragColor = vec4(vertexColor.xxz, 1.0);;
}

运行结果：