我最近一直在学习C ++,并且一直在尝试创建一个分为头文件和源文件的简单类。但是,我似乎继续收到此错误:
ship.cpp:21:9: error: use of undeclared identifier 'image'
return image;
^
1 error generated.
我已包含以下源代码:
main.cpp:
#include <iostream>
#include <allegro5/allegro.h>
#include <allegro5/allegro_image.h>
#include <allegro5/allegro_native_dialog.h>
#include <ship.h>
int main(int argc, char **argv){
ALLEGRO_DISPLAY *display = nullptr;
ALLEGRO_BITMAP *image = nullptr;
if(!al_init()){
al_show_native_message_box(display, "Error", "Error", "Failed to initialise allegro", NULL, ALLEGRO_MESSAGEBOX_ERROR);
return 0;
}
if(!al_init_image_addon()) {
al_show_native_message_box(display, "Error", "Error", "Failed to initialize al_init_image_addon!", NULL, ALLEGRO_MESSAGEBOX_ERROR);
return 0;
}
display = al_create_display(800,600);
if(!display) {
al_show_native_message_box(display, "Error", "Error", "Failed to initialize display!", NULL, ALLEGRO_MESSAGEBOX_ERROR);
return 0;
}
Ship ship("image.jpg");
al_draw_bitmap(ship.get_image(), 200, 200, 0);
al_flip_display();
al_rest(2);
return 0;
}
ship.h:
#ifndef SHIP_H
#define SHIP_H
#include <iostream>
#include <allegro5/allegro.h>
#include <allegro5/allegro_image.h>
class Ship
{
ALLEGRO_BITMAP *image;
private:
int width;
int height;
public:
Ship(std::string image_file);
ALLEGRO_BITMAP *get_image();
};
#endif
ship.cpp:
#include <allegro5/allegro.h>
#include <allegro5/allegro_image.h>
#include <allegro5/allegro_native_dialog.h>
#include <iostream>
#include <ship.h>
Ship::Ship(std::string image_file){
image = al_load_bitmap(image_file.c_str());
if(image == nullptr){
std::cout << "Ship went down." << std::endl;
}
std::cout << "Ship loaded successfully." << std::endl;
}
ALLEGRO_BITMAP *get_image(){
return image;
}
最佳答案
您未正确定义函数。 get_image()
是Ship
类的成员。您的定义将创建一个独立的函数。
ALLEGRO_BITMAP *get_image(){
应该:
ALLEGRO_BITMAP* Ship::get_image(){
(为便于阅读,将星号重新定位)
关于c++ - 使用未声明的标识符C++,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/32704783/