C ++ SDL - MVS LNK2019

Question

我刚开始使用Lazy Foo教程在C ++中使用SDL进行编程，而且我对目标编程并不熟悉。我已经开始收到LNK2019错误，但找不到它的原因。

我有一个类LTexture：

#pragma once
#include<string>
#include<SDL.h>
#include<SDL_image.h>
class LTexture
{
    public:
        LTexture();
        ~LTexture();
        //Loads image at specified path
        bool loadFromFile(std::string path, SDL_Renderer* _gameRenderer);
        void free();
        //Renders texture at given point
        void render(int x, int y, SDL_Renderer* _gameRenderer);
        int getWidth();
        int getHeight();
    private:
        //The actual hardware texture
        SDL_Texture* _texture;
        //Image dimensions
        int _width;
        int _height;
};

#pragma once #include<string> #include<SDL.h> #include<SDL_image.h> class LTexture { public: LTexture(); ~LTexture(); //Loads image at specified path bool loadFromFile(std::string path, SDL_Renderer* _gameRenderer); void free(); //Renders texture at given point void render(int x, int y, SDL_Renderer* _gameRenderer); int getWidth(); int getHeight(); private: //The actual hardware texture SDL_Texture* _texture; //Image dimensions int _width; int _height; };

一个AssetLoader类：

#pragma once

#include <stdio.h>
#include<iostream>
#include "LTexture.hpp"

class AssetLoader
{
    public:
        //Loads media
        bool loadMedia(SDL_Renderer* _gameRenderer);        
        //Loads individual image as texture
        SDL_Texture* loadTexture(std::string path, SDL_Renderer* _gameRenderer);
        //Scene textures
        LTexture gFooTexture;
        LTexture gBackgroundTexture;

};

我得到的错误： 严重性代码描述项目文件行抑制状态 错误LNK2019未解析的外部符号“public：bool __thiscall LTexture :: loadFromFile（class std :: basic_string，class std :: allocator＆gt;，struct SDL_Renderer *）”（？loadFromFile @ LTexture @@ QAE_NV？$ basic_string @ DU？$ char_traits @ D @ std @@ V？$ allocator @ D @ 2 @@ std @@ PAUSDL_Renderer @@@ Z）在函数“public：bool __thiscall AssetLoader :: loadMedia（struct SDL_Renderer *）”中引用（？loadMedia @ AssetLoader @@ QAE_NPAUSDL_Renderer @@@ Z）

严重级代码描述项目文件行抑制状态 错误LNK2019未解析的外部符号“public：__thiscall LTexture :: LTexture（void）”（?? 0LTexture @@ QAE @ XZ）在函数“public：__thiscall AssetLoader :: AssetLoader（void）”中引用（?? 0AssetLoader @@ QAE @ XZ）

严重级代码描述项目文件行抑制状态 错误LNK2019未解析的外部符号“public：__thiscall LTexture :: ~LTexture（void）”（?? 1LTexture @@ QAE @ XZ）在函数__unwindfunclet中引用$ ?? 0AssetLoader @@ QAE @XZ $ 0

当它试图在AssetLoader :: loadMedia函数中调用LTexture :: loadFromFile函数时显然失败，如下所示：

#pragma once #include <stdio.h> #include<iostream> #include "LTexture.hpp" class AssetLoader { public: //Loads media bool loadMedia(SDL_Renderer* _gameRenderer); //Loads individual image as texture SDL_Texture* loadTexture(std::string path, SDL_Renderer* _gameRenderer); //Scene textures LTexture gFooTexture; LTexture gBackgroundTexture; };

LTexture :: loadFromFile的实现是这样的：

#pragma once

#include"AssetLoader.hpp"
#include"LTexture.hpp"
bool AssetLoader::loadMedia(SDL_Renderer* _gameRenderer)
{
    //Loading success flag
    bool _success = true;

    //Load splash image
    if (!gFooTexture.loadFromFile("foo.png", _gameRenderer))
    {
        printf("Failed to load Foo texture image!\n");
        _success = false;
    }

    //Load background texture
    if (!gBackgroundTexture.loadFromFile("background.png", _gameRenderer))
    {
        printf("Failed to load background texture image!\n");
        _success = false;
    }

    return _success;
}

#pragma once #include"AssetLoader.hpp" #include"LTexture.hpp" bool AssetLoader::loadMedia(SDL_Renderer* _gameRenderer) { //Loading success flag bool _success = true; //Load splash image if (!gFooTexture.loadFromFile("foo.png", _gameRenderer)) { printf("Failed to load Foo texture image!\n"); _success = false; } //Load background texture if (!gBackgroundTexture.loadFromFile("background.png", _gameRenderer)) { printf("Failed to load background texture image!\n"); _success = false; } return _success; }

请帮助，我真的无处可问。