c++ - C++ 中的“类”类型重新定义错误 C2011
问题描述
这是我的头文件:
#ifndef SOMETHING_H
#define SOMETHING_H
#include <SDL.h>
#include <stdio.h>
#include <string>
#pragma once
class Something {
public:
//Screen dimension constants
int SCREEN_WIDTHS;
int SCREEN_HEIGHTS;
//Starts up SDL and creates window
bool inits();
//Loads media
bool loadMediases();
//Frees media and shuts down SDL
void closes();
Something(int height);
int mains();
//Loads individual image
SDL_Surface* loadSurfaces(std::string path);
//The window we'll be rendering to
SDL_Window* gWindows;
//The surface contained by the window
SDL_Surface* gScreenSurfaces;
//The images that correspond to a keypress
SDL_Surface* gKeyPressSurfaceses[5];
//Current displayed image
SDL_Surface* gCurrentSurfaces;
};
#endif
这是我的 cpp 文件:
//Using SDL, standard IO, and strings
#include <SDL.h>
#include <stdio.h>
#include <string>
#include "Something.h"
class Something {
public:
//Screen dimension constants
int SCREEN_WIDTHS = 640;
int SCREEN_HEIGHTS = 480;
//Key press surfaces constants
enum KeyPressSurfaceses
{
KEY_PRESS_SURFACE_DEFAULT,
KEY_PRESS_SURFACE_UP,
KEY_PRESS_SURFACE_DOWN,
KEY_PRESS_SURFACE_LEFT,
KEY_PRESS_SURFACE_RIGHT,
KEY_PRESS_SURFACE_TOTAL
};
//The window we'll be rendering to
SDL_Window* gWindows = NULL;
//The surface contained by the window
SDL_Surface* gScreenSurfaces = NULL;
//The images that correspond to a keypress
SDL_Surface* gKeyPressSurfaceses[KEY_PRESS_SURFACE_TOTAL];
//Current displayed image
SDL_Surface* gCurrentSurfaces = NULL;
Something(int height) {
SCREEN_HEIGHTS = height;
}
bool inits()
{
//Initialization flag
bool success = true;
//Initialize SDL
if (SDL_Init(SDL_INIT_VIDEO) < 0)
{
printf("SDL could not initialize! SDL Error: %s\n", SDL_GetError());
success = false;
}
else
{
//Create window
gWindows = SDL_CreateWindow("SDL Tutorial", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTHS, SCREEN_HEIGHTS, SDL_WINDOW_SHOWN);
if (gWindows == NULL)
{
printf("Window could not be created! SDL Error: %s\n", SDL_GetError());
success = false;
}
else
{
//Get window surface
gScreenSurfaces = SDL_GetWindowSurface(gWindows);
}
}
return success;
}
bool loadMedias()
{
//Loading success flag
bool success = true;
//Load default surface
gKeyPressSurfaceses[KEY_PRESS_SURFACE_DEFAULT] = loadSurfaces("resources/images/press.bmp");
if (gKeyPressSurfaceses[KEY_PRESS_SURFACE_DEFAULT] == NULL)
{
printf("Failed to load default image!\n");
success = false;
}
//Load up surface
gKeyPressSurfaceses[KEY_PRESS_SURFACE_UP] = loadSurfaces("resources/images/up.bmp");
if (gKeyPressSurfaceses[KEY_PRESS_SURFACE_UP] == NULL)
{
printf("Failed to load up image!\n");
success = false;
}
//Load down surface
gKeyPressSurfaceses[KEY_PRESS_SURFACE_DOWN] = loadSurfaces("resources/images/down.bmp");
if (gKeyPressSurfaceses[KEY_PRESS_SURFACE_DOWN] == NULL)
{
printf("Failed to load down image!\n");
success = false;
}
//Load left surface
gKeyPressSurfaceses[KEY_PRESS_SURFACE_LEFT] = loadSurfaces("resources/images/left.bmp");
if (gKeyPressSurfaceses[KEY_PRESS_SURFACE_LEFT] == NULL)
{
printf("Failed to load left image!\n");
success = false;
}
//Load right surface
gKeyPressSurfaceses[KEY_PRESS_SURFACE_RIGHT] = loadSurfaces("resources/images/right.bmp");
if (gKeyPressSurfaceses[KEY_PRESS_SURFACE_RIGHT] == NULL)
{
printf("Failed to load right image!\n");
success = false;
}
return success;
}
void closes()
{
//Deallocate surfaces
for (int i = 0; i < KEY_PRESS_SURFACE_TOTAL; ++i)
{
SDL_FreeSurface(gKeyPressSurfaceses[i]);
gKeyPressSurfaceses[i] = NULL;
}
//Destroy window
SDL_DestroyWindow(gWindows);
gWindows = NULL;
//Quit SDL subsystems
SDL_Quit();
}
SDL_Surface* loadSurfaces(std::string path)
{
//Load image at specified path
SDL_Surface* loadedSurface = SDL_LoadBMP(path.c_str());
if (loadedSurface == NULL)
{
printf("Unable to load image %s! SDL Error: %s\n", path.c_str(), SDL_GetError());
}
return loadedSurface;
}
int mains(int argc, char* args[])
{
//Start up SDL and create window
if (!inits())
{
printf("Failed to initialize!\n");
}
else
{
//Load media
if (!loadMedias())
{
printf("Failed to load media!\n");
}
else
{
//Main loop flag
bool quit = false;
//Event handler
SDL_Event e;
//Set default current surface
gCurrentSurfaces = gKeyPressSurfaceses[KEY_PRESS_SURFACE_DEFAULT];
//While application is running
while (!quit)
{
//Handle events on queue
while (SDL_PollEvent(&e) != 0)
{
//User requests quit
if (e.type == SDL_QUIT)
{
quit = true;
}
//User presses a key
else if (e.type == SDL_KEYDOWN)
{
//Select surfaces based on key press
switch (e.key.keysym.sym)
{
case SDLK_UP:
gCurrentSurfaces = gKeyPressSurfaceses[KEY_PRESS_SURFACE_UP];
break;
case SDLK_DOWN:
gCurrentSurfaces = gKeyPressSurfaceses[KEY_PRESS_SURFACE_DOWN];
break;
case SDLK_LEFT:
gCurrentSurfaces = gKeyPressSurfaceses[KEY_PRESS_SURFACE_LEFT];
break;
case SDLK_RIGHT:
gCurrentSurfaces = gKeyPressSurfaceses[KEY_PRESS_SURFACE_RIGHT];
break;
default:
gCurrentSurfaces = gKeyPressSurfaceses[KEY_PRESS_SURFACE_DEFAULT];
break;
}
}
}
//Apply the current image
SDL_BlitSurface(gCurrentSurfaces, NULL, gScreenSurfaces, NULL);
//Update the surface
SDL_UpdateWindowSurface(gWindows);
}
}
}
//Free resources and close SDL
closes();
return 0;
}
};
为什么它不断抛出“类”类型重新定义错误?我怎样才能解决这个问题?我已经尝试了一切,但我遇到了更多问题。我看到一些帖子将这个问题与两次定义类有关,但是摆脱 cpp 中的类定义并使用 classname::functionname 只会导致更多错误。
我知道这是一个愚蠢的问题,我是使用教程和 Visual Studio 的初级 C++ 程序员。
解决方案
在您的 .cpp 文件中,您已经完全重新声明了class Something
. 如果您只想将函数的实现放在 .cpp 文件中,那不是您的做法。
那里的语法应该是这样的:
bool Something::inits()
{
// implementation ...
}
bool Something::loadMedias()
{
// implementation ...
}
等等
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