c++ - 从函数 C++/SFML 加载资源时出现问题

Question

我有一个结构，用于在标题中声明纹理、 Sprite 、音乐、字体、声音等。然后我使用相应的 .cpp 文件将所述纹理设置为其相应的 Sprite ，等等。

我在 main 中创建了结构对象，并调用了该函数。但是当我构建我的程序时，我得到了一百万个“未声明的标识符”错误。我究竟做错了什么？这是我的代码:

资源.h:

#ifndef __SFML__resources__
#define __SFML__resources__

#include "SFML/Audio.hpp"
#include "SFML/Graphics.hpp"

struct resources
{
float opacity = 1.0;

sf::Texture texturePlayer;
sf::Texture textureSettingsMenu;
sf::Sprite spriteSaveMenu;
sf::Sprite spriteSettingsMenu;
//start screen texture
sf::Texture textureStart;
//gamestate background sprite
sf::Sprite spriteScreen;
sf::Font font;
sf::Font font2;
int loadResources();
// hundreds more lines of declarations below
//...
};
#endif

资源.cpp:

#include "resources.h"


int resources::loadResources()
{
if (!textureSaveMenu.loadFromFile("images/magicmenu3.png"))
    return EXIT_FAILURE;


if (!textureSettingsMenu.loadFromFile("images/inventorymenu.png"))
    return EXIT_FAILURE;

spriteSaveMenu.setTexture(textureSaveMenu);
spriteSettingsMenu.setTexture(textureSettingsMenu);

if (!textureStart.loadFromFile("images/skyocean.png"))
    return EXIT_FAILURE;

if (!font.loadFromFile("fonts/arial.ttf"))
    return EXIT_FAILURE;

if (!font2.loadFromFile("fonts/dominican.ttf"))
    return EXIT_FAILURE;

if (!musicBattle.openFromFile("audio/musicBattle.ogg"))
    return EXIT_FAILURE;
musicBattle.setVolume(20);
musicBattle.setLoop(true);


if (!musicOpening.openFromFile("audio/maintheme.ogg"))
    return EXIT_FAILURE;
musicOpening.setVolume(30);
musicOpening.setLoop(true);

if (!musicDefeat.openFromFile("audio/defeat.ogg"))
    return EXIT_FAILURE;
musicDefeat.setVolume(50);
musicDefeat.setLoop(true);

if (!musicForest.openFromFile("audio/forest.ogg"))
    return EXIT_FAILURE;
musicForest.setVolume(10);
musicForest.setLoop(true);

if (!musicWorldMap.openFromFile("audio/bluefields.ogg"))
    return EXIT_FAILURE;
musicWorldMap.setVolume(40);
musicWorldMap.setLoop(true);

if (!musicVillage.openFromFile("audio/welcomehome.ogg"))
    return EXIT_FAILURE;
musicVillage.setVolume(40);
musicVillage.setLoop(true);

//every single declared resource is set within this function
//but the function is too large to display fully here
}

主要.cpp:

 #include "SFML/Audio.hpp"
 #include "SFML/Graphics.hpp"
 #include <iostream>
 #include "random.h"
 #include "player.h"
 #include "entity.h"
 #include "projectile.h"
 #include "enemy.h"
 #include "textDisplay.h"
 #include "pickup.h"
 #include "wall.h"
 #include "sword.h"
 #include "npc.h"
 #include "battlemenu.h"
 #include "cursor.h"
 #include "name.h"
 #include "itemshop.h"
 #include "characterselection.h"
 #include "mainmenu.h"
 #include "exp.h"
 #include "drops.h"
 #include "weaponshop.h"
 #include "armorshop.h"
 #include "startmenu.h"
 #include "room.h"
 #include "resources.h"


int main()
{
//create the main window
sf::RenderWindow window(sf::VideoMode(720, 500), "Sky Ocean");
window.setFramerateLimit(60);
window.setKeyRepeatEnabled(false);

//View
sf::View view1(sf::FloatRect(200, 200, 300, 200));
view1.setSize(sf::Vector2f(window.getSize().x, window.getSize().y));
view1.setCenter(sf::Vector2f(view1.getSize().x / 2, view1.getSize().y / 2));
window.setView(view1);

//load resources
struct resources resources1;
resources1.loadResources();

//class object
class player Player1;
Player1.sprite.setTexture(texturePlayer);

class player Player2;
Player2.sprite.setTexture(texturePlayer);
Player2.rect.setScale(1.6, 1.6);
Player2.sprite.setScale(1.6, 1.6);

//...
}

Answer 1

首先，我推荐你阅读something关于头文件。

---

resources.h 确实不包含所用标识符的声明。

您必须#include 包含这些声明的头文件，这样编译器才能看到它们。请阅读SFML declaration查看需要包含哪些模块并将它们#include 到头文件 中，现在您只将它们包含到main.cpp 中，所以只main.cpp 包含标识符的声明。当编译器读取 resources.cpp 时，它看不到这些声明，因此出现 undeclared identifier 错误。

例如，resources.h 应如下所示:

//...

#include "entity.h"

#include <SFML/Graphics.hpp>
#include <Whatever.hpp>

struct resources
{

//...