Question

所以我正在从learnopengl开始研究 opengl 项目，而且我是C ++的初学者，所以我没有遇到什么问题。这是一个VS2017项目。

我遇到main.cpp的问题，当我编译它时会显示此错误：

名称后跟＆＃39; ::＆＃39;必须是类或命名空间


它在（FileSystem :: getPath）中，所以当我在main.cpp中包含filesystem.h时，它显示另一个错误但在filesystem.h中：无法打开   源文件＆＃34; root_directory.h＆＃34;

所以我从root_directory.h下载了entry.h logl_root filesystem.h。现在我有10个警告和3个错误:-)这就是当一个人想修复一个错误时会发生什么。

**filesystem.h** #ifndef FILESYSTEM_H #define FILESYSTEM_H #include <string> #include <cstdlib> #include "root_directory.h" // This is a configuration file generated by CMake. class FileSystem { private: typedef std::string (*Builder) (const std::string& path); public: static std::string getPath(const std::string& path) { static std::string(*pathBuilder)(std::string const &) = getPathBuilder(); return (*pathBuilder)(path); } private: static std::string const & getRoot() { static char const * envRoot = getenv("LOGL_ROOT_PATH"); static char const * givenRoot = (envRoot != nullptr ? envRoot : logl_root); static std::string root = (givenRoot != nullptr ? givenRoot : ""); return root; } //static std::string(*foo (std::string const &)) getPathBuilder() static Builder getPathBuilder() { if (getRoot() != "") return &FileSystem::getPathRelativeRoot; else return &FileSystem::getPathRelativeBinary; } static std::string getPathRelativeRoot(const std::string& path) { return getRoot() + std::string("/") + path; } static std::string getPathRelativeBinary(const std::string& path) { return "../../../" + path; } }; // FILESYSTEM_H #endif **root_directory.h** #ifndef __ROOT #define __ROOT #include "entry.h" #include <iostream> #include <vector> #include <string> #include <ctime> using namespace std; class RootDirectory { public: vector <Entry> data; RootDirectory(); string toString(); void load(string); }; #endif#ifndef __ROOT #define __ROOT #include "entry.h" #include <iostream> #include <vector> #include <string> #include <ctime> using namespace std; class RootDirectory { public: vector <Entry> data; RootDirectory(); string toString(); void load(string); }; #endif **main.cpp** #include <glad/glad.h> #include <GLFW/glfw3.h> #include <stb_image.h> #include <glm/glm.hpp> #include <glm/gtc/matrix_transform.hpp> #include <glm/gtc/type_ptr.hpp> #include <learnopengl/shader_m.h> #include <learnopengl/camera.h> #include <learnopengl/filesystem.h> #include <iostream> void framebuffer_size_callback(GLFWwindow* window, int width, int height); void mouse_callback(GLFWwindow* window, double xpos, double ypos); void scroll_callback(GLFWwindow* window, double xoffset, double yoffset); void processInput(GLFWwindow *window); unsigned int loadTexture(const char *path); // settings const unsigned int SCR_WIDTH = 800; const unsigned int SCR_HEIGHT = 600; // camera Camera camera(glm::vec3(0.0f, 0.0f, 3.0f)); float lastX = SCR_WIDTH / 2.0f; float lastY = SCR_HEIGHT / 2.0f; bool firstMouse = true; // timing float deltaTime = 0.0f; float lastFrame = 0.0f; int main() { // glfw: initialize and configure // ------------------------------ glfwInit(); glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3); glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); #ifdef __APPLE__ glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); #endif // glfw window creation // -------------------- GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL); if (window == NULL) { std::cout << "Failed to create GLFW window" << std::endl; glfwTerminate(); return -1; } glfwMakeContextCurrent(window); glfwSetFramebufferSizeCallback(window, framebuffer_size_callback); glfwSetCursorPosCallback(window, mouse_callback); glfwSetScrollCallback(window, scroll_callback); // tell GLFW to capture our mouse glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED); // glad: load all OpenGL function pointers // --------------------------------------- if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) { std::cout << "Failed to initialize GLAD" << std::endl; return -1; } // configure global opengl state // ----------------------------- glEnable(GL_DEPTH_TEST); // build and compile our shader zprogram // ------------------------------------ Shader lightingShader("5.4.light_casters.vs", "5.4.light_casters.fs"); Shader lampShader("5.4.lamp.vs", "5.4.lamp.fs"); // set up vertex data (and buffer(s)) and configure vertex attributes // ------------------------------------------------------------------ float vertices[] = { // positions // normals // texture coords -0.5f, -0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 0.0f, 0.0f, 0.5f, -0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 1.0f, 0.0f, 0.5f, 0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 1.0f, 1.0f, 0.5f, 0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 1.0f, 1.0f, -0.5f, 0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 0.0f, 1.0f, -0.5f, -0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 0.0f, 0.0f, -0.5f, -0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.5f, -0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.5f, 0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.5f, 0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, -0.5f, 0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, -0.5f, -0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, -0.5f, 0.5f, 0.5f, -1.0f, 0.0f, 0.0f, 1.0f, 0.0f, -0.5f, 0.5f, -0.5f, -1.0f, 0.0f, 0.0f, 1.0f, 1.0f, -0.5f, -0.5f, -0.5f, -1.0f, 0.0f, 0.0f, 0.0f, 1.0f, -0.5f, -0.5f, -0.5f, -1.0f, 0.0f, 0.0f, 0.0f, 1.0f, -0.5f, -0.5f, 0.5f, -1.0f, 0.0f, 0.0f, 0.0f, 0.0f, -0.5f, 0.5f, 0.5f, -1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.5f, 0.5f, 0.5f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.5f, 0.5f, -0.5f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.5f, -0.5f, -0.5f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.5f, -0.5f, -0.5f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.5f, -0.5f, 0.5f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.5f, 0.5f, 0.5f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, -0.5f, -0.5f, -0.5f, 0.0f, -1.0f, 0.0f, 0.0f, 1.0f, 0.5f, -0.5f, -0.5f, 0.0f, -1.0f, 0.0f, 1.0f, 1.0f, 0.5f, -0.5f, 0.5f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f, 0.5f, -0.5f, 0.5f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f, -0.5f, -0.5f, 0.5f, 0.0f, -1.0f, 0.0f, 0.0f, 0.0f, -0.5f, -0.5f, -0.5f, 0.0f, -1.0f, 0.0f, 0.0f, 1.0f, -0.5f, 0.5f, -0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.5f, 0.5f, -0.5f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.5f, 0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, 0.5f, 0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, -0.5f, 0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, -0.5f, 0.5f, -0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f }; // positions all containers glm::vec3 cubePositions[] = { glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(2.0f, 5.0f, -15.0f), glm::vec3(-1.5f, -2.2f, -2.5f), glm::vec3(-3.8f, -2.0f, -12.3f), glm::vec3(2.4f, -0.4f, -3.5f), glm::vec3(-1.7f, 3.0f, -7.5f), glm::vec3(1.3f, -2.0f, -2.5f), glm::vec3(1.5f, 2.0f, -2.5f), glm::vec3(1.5f, 0.2f, -1.5f), glm::vec3(-1.3f, 1.0f, -1.5f) }; // first, configure the cube's VAO (and VBO) unsigned int VBO, cubeVAO; glGenVertexArrays(1, &cubeVAO); glGenBuffers(1, &VBO); glBindBuffer(GL_ARRAY_BUFFER, VBO); glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW); glBindVertexArray(cubeVAO); glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0); glEnableVertexAttribArray(0); glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float))); glEnableVertexAttribArray(1); glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float))); glEnableVertexAttribArray(2); // second, configure the light's VAO (VBO stays the same; the vertices are the same for the light object which is also a 3D cube) unsigned int lightVAO; glGenVertexArrays(1, &lightVAO); glBindVertexArray(lightVAO); glBindBuffer(GL_ARRAY_BUFFER, VBO); // note that we update the lamp's position attribute's stride to reflect the updated buffer data glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0); glEnableVertexAttribArray(0); // load textures (we now use a utility function to keep the code more organized) // ----------------------------------------------------------------------------- unsigned int diffuseMap = loadTexture(FileSystem::getPath("resources/textures/container2.png").c_str()); unsigned int specularMap = loadTexture(FileSystem::getPath("resources/textures/container2_specular.png").c_str()); // shader configuration // -------------------- lightingShader.use(); lightingShader.setInt("material.diffuse", 0); lightingShader.setInt("material.specular", 1); // render loop // ----------- while (!glfwWindowShouldClose(window)) { // per-frame time logic // -------------------- float currentFrame = glfwGetTime(); deltaTime = currentFrame - lastFrame; lastFrame = currentFrame; // input // ----- processInput(window); // render // ------ glClearColor(0.1f, 0.1f, 0.1f, 1.0f); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // be sure to activate shader when setting uniforms/drawing objects lightingShader.use(); lightingShader.setVec3("light.position", camera.Position); lightingShader.setVec3("light.direction", camera.Front); lightingShader.setFloat("light.cutOff", glm::cos(glm::radians(12.5f))); lightingShader.setFloat("light.outerCutOff", glm::cos(glm::radians(17.5f))); lightingShader.setVec3("viewPos", camera.Position); // light properties lightingShader.setVec3("light.ambient", 0.1f, 0.1f, 0.1f); // we configure the diffuse intensity slightly higher; the right lighting conditions differ with each lighting method and environment. // each environment and lighting type requires some tweaking to get the best out of your environment. lightingShader.setVec3("light.diffuse", 0.8f, 0.8f, 0.8f); lightingShader.setVec3("light.specular", 1.0f, 1.0f, 1.0f); lightingShader.setFloat("light.constant", 1.0f); lightingShader.setFloat("light.linear", 0.09f); lightingShader.setFloat("light.quadratic", 0.032f); // material properties lightingShader.setFloat("material.shininess", 32.0f); // view/projection transformations glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f); glm::mat4 view = camera.GetViewMatrix(); lightingShader.setMat4("projection", projection); lightingShader.setMat4("view", view); // world transformation glm::mat4 model; lightingShader.setMat4("model", model); // bind diffuse map glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, diffuseMap); // bind specular map glActiveTexture(GL_TEXTURE1); glBindTexture(GL_TEXTURE_2D, specularMap); // render containers glBindVertexArray(cubeVAO); for (unsigned int i = 0; i < 10; i++) { // calculate the model matrix for each object and pass it to shader before drawing glm::mat4 model; model = glm::translate(model, cubePositions[i]); float angle = 20.0f * i; model = glm::rotate(model, glm::radians(angle), glm::vec3(1.0f, 0.3f, 0.5f)); lightingShader.setMat4("model", model); glDrawArrays(GL_TRIANGLES, 0, 36); } // again, a lamp object is weird when we only have a spot light, don't render the light object // lampShader.use(); // lampShader.setMat4("projection", projection); // lampShader.setMat4("view", view); // model = glm::mat4(); // model = glm::translate(model, lightPos); // model = glm::scale(model, glm::vec3(0.2f)); // a smaller cube // lampShader.setMat4("model", model); // glBindVertexArray(lightVAO); // glDrawArrays(GL_TRIANGLES, 0, 36); // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.) // ------------------------------------------------------------------------------- glfwSwapBuffers(window); glfwPollEvents(); } // optional: de-allocate all resources once they've outlived their purpose: // ------------------------------------------------------------------------ glDeleteVertexArrays(1, &cubeVAO); glDeleteVertexArrays(1, &lightVAO); glDeleteBuffers(1, &VBO); // glfw: terminate, clearing all previously allocated GLFW resources. // ------------------------------------------------------------------ glfwTerminate(); return 0; } // process all input: query GLFW whether relevant keys are pressed/released this frame and react accordingly // --------------------------------------------------------------------------------------------------------- void processInput(GLFWwindow *window) { if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS) glfwSetWindowShouldClose(window, true); if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS) camera.ProcessKeyboard(FORWARD, deltaTime); if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS) camera.ProcessKeyboard(BACKWARD, deltaTime); if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS) camera.ProcessKeyboard(LEFT, deltaTime); if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS) camera.ProcessKeyboard(RIGHT, deltaTime); } // glfw: whenever the window size changed (by OS or user resize) this callback function executes // --------------------------------------------------------------------------------------------- void framebuffer_size_callback(GLFWwindow* window, int width, int height) { // make sure the viewport matches the new window dimensions; note that width and // height will be significantly larger than specified on retina displays. glViewport(0, 0, width, height); } // glfw: whenever the mouse moves, this callback is called // ------------------------------------------------------- void mouse_callback(GLFWwindow* window, double xpos, double ypos) { if (firstMouse) { lastX = xpos; lastY = ypos; firstMouse = false; } float xoffset = xpos - lastX; float yoffset = lastY - ypos; // reversed since y-coordinates go from bottom to top lastX = xpos; lastY = ypos; camera.ProcessMouseMovement(xoffset, yoffset); } // glfw: whenever the mouse scroll wheel scrolls, this callback is called // ---------------------------------------------------------------------- void scroll_callback(GLFWwindow* window, double xoffset, double yoffset) { camera.ProcessMouseScroll(yoffset); } // utility function for loading a 2D texture from file // --------------------------------------------------- unsigned int loadTexture(char const * path) { unsigned int textureID; glGenTextures(1, &textureID); int width, height, nrComponents; unsigned char *data = stbi_load(path, &width, &height, &nrComponents, 0); if (data) { GLenum format; if (nrComponents == 1) format = GL_RED; else if (nrComponents == 3) format = GL_RGB; else if (nrComponents == 4) format = GL_RGBA; glBindTexture(GL_TEXTURE_2D, textureID); glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, data); glGenerateMipmap(GL_TEXTURE_2D); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); stbi_image_free(data); } else { std::cout << "Texture failed to load at path: " << path << std::endl; stbi_image_free(data); } return textureID; }来自# here select the G element that contains the elements we want to transform function zoomed() { var toModify = d3.select('#damnCircles') .attr("transform", d3.event.transform); } # here select the first G element under SVG as event listener. var svg = d3.select("#svg").select('g') .call(zoom);的未声明标识符23 next＆＃39; getenv＆＃39;：此函数或变量可能不安全。请考虑使用_dupenv_s。要禁用弃用，请使用_CRT_SECURE_NO_WARNINGS。欢迎各方面的帮助。

我知道我只是初学者，但如果不尝试处理问题，我该如何学习呢？我知道这个问题有多愚蠢：D ......

如果7z中的完整项目： https://github.com/alifradityar/LastOrder

filesystem.h，root_directory.h和entry.h位于/ includes / learnopengl中 lib-s和includes在VS中链接。

line：24 - logl_root undefined 23 - ＆＃39; getenv＆＃39;：此功能或变量可能不安全。请考虑使用_dupenv_s。要禁用弃用，请使用_CRT_SECURE_NO_WARNINGS。欢迎提供每一个帮助。

success: function(){
  //Now loop through checkbox
   $(".rightCheck").each(function(){
    if($(this).attr("id") == id) //check if checkbox id match
    {
      $(this).prop("checked",true);
    }
   });  
}

Answer 1

我将此作为答案而不是评论（尽管我可能应该是评论）。正如你告诉自己你想学习的那样。因此，我不会告诉你一个解决方案，而是试图告诉你如何正确处理这类问题。

首先，处理编译错误时最重要的部分是实际读取错误消息，然后理解它！ 不要妄下结论，从不相关的来源下载任意文件并将各种东西混合在一起！这种方法不起作用！

让我们打破这个局面。您有编译器错误。它的内容如下：

(…) name followed by '::' must be a class or namespace (…)

遗憾的是，您的引用缺少一些信息，即问题所在的哪个行的文件。编译器如何报告错误背后有一定的逻辑;旧版本的GCC吐出相当神秘的错误日志，通常是几页长;罪魁祸首通常隐藏在整个错误日志的前5行左右。通常你可以安全地忽略所有其他的。

无论如何，它会告诉你什么是错的。也就是说，在C ++中，如果你写的是a::b，那么a必须是类的名称或命名空间（这正是错误告诉你的）。但是，通常类和名称空间由标头include引入。如果一个include指令失败，那么预处理器确实会挽救，所以这根本不可能与缺少的包含有任何关系。

但也可能发生的事情是，之前包含某些内容并不是它应该如何。通常缺少分号（;）。这可能会导致类声明被其他东西搞砸。

所以你应该做什么：从头开始重新阅读编译器日志。查看顶部的所有警告和错误，然后逐步降低。

如果您再次陷入困境，编辑您的问题，如果我可以帮助您，我会附加到此答案。

Answer 2

如果有人仍在寻找答案...

// FileSystem :: getPath（...）是GitHub存储库的一部分，因此我们可以在任何IDE /平台上找到文件；用您自己的图像路径替换它。

多个错误，在VS2017的头文件中，opengl项目C ++

2 个答案: