我不知道这是什么（C++连接错误）

得到这个我不知道这是什么（C++连接错误）

1>main_display.obj : error LNK2005: "struct ALLEGRO_DISPLAY * main_display" ([email protected]@[email protected]@A) already defined in event_queue.obj 
1>main.obj : error LNK2005: "struct ALLEGRO_DISPLAY * main_display" ([email protected]@[email protected]@A) already defined in event_queue.obj 
1>main.obj : error LNK2005: "struct ALLEGRO_TIMER * timer" ([email protected]@[email protected]@A) already defined in event_queue.obj 
1>main.obj : error LNK2005: "struct ALLEGRO_EVENT_QUEUE * event_queue" ([email protected]@[email protected]@A) already defined in event_queue.obj 
1>main_timer.obj : error LNK2005: "struct ALLEGRO_TIMER * timer" ([email protected]@[email protected]@A) already defined in event_queue.obj

任何想法可能会导致此？

编辑：

main_display.h：

#pragma once 

#include <allegro5/allegro.h> 
#include <stdio.h> 

#define SCREEN_W 640 
#define SCREEN_H 480 

extern ALLEGRO_DISPLAY *main_display = NULL; 

void display_init(); 
void destroy_display();

event_queue.h

#pragma once 

#include <stdio.h> 
#include <allegro5/allegro.h> 
#include "main_timer.h" 
#include "main_display.h" 

extern ALLEGRO_EVENT_QUEUE *event_queue = NULL; 

void event_queue_init(); 
void event_queue_destroy();

来源

2011-10-19 Vladp

我没有结构....和名称是免费的... – Vladp