我的类 GraphicsManager 出现错误。

图形管理器.cpp:

#include "C:\Users\Chris Uzzolina\Desktop\obj\include\GraphicsManager.h"
#include <SDL.h>
#include <string>
GraphicsManager::GraphicsManager(int SCREEN_WIDTH, int SCREEN_HEIGHT, int SCREEN_BPP,  std::string caption, SDL_Surface *screen)
{

}

GraphicsManager::~GraphicsManager()
{
    //dtor
}
bool init(int SCREEN_WIDTH, int SCREEN_HEIGHT, int SCREEN_BPP, std::string caption, SDL_Surface *scr)
{
    //Initialize all SDL subsystems
    if( SDL_Init( SDL_INIT_EVERYTHING ) == -1 )
    {
        return false;
    }

    //Set up the screen
    scr = SDL_SetVideoMode( SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP, SDL_SWSURFACE );

    //If there was an error in setting up the screen
    if( scr == NULL )
    {
        return false;
    }

    //Set the window caption
    SDL_WM_SetCaption( "Event test", NULL );

    //If everything initialized fine
    return true;
}

SDL_Surface *load_image( std::string filename )
{
    //Temporary storage for the image that's loaded
    SDL_Surface* loadedImage = NULL;

    //The optimized image that will be used
    SDL_Surface* optimizedImage = NULL;
    //Load the image
    loadedImage = SDL_LoadBMP( filename.c_str() );
    //If nothing went wrong in loading the image
    if( loadedImage != NULL )
    {
        //Create an optimized image
        optimizedImage = SDL_DisplayFormat( loadedImage );

        //Free the old image
        SDL_FreeSurface( loadedImage );
    }
    //Return the optimized image
    return optimizedImage;
}

void apply_surface( int x, int y, SDL_Surface* source, SDL_Surface* destination )
{
    //Make a temporary rectangle to hold the offsets
    SDL_Rect offset;

    //Give the offsets to the rectangle
    offset.x = x;
    offset.y = y;
    //Blit the surface
    SDL_BlitSurface( source, NULL, destination, &offset );
}

void clean_up(SDL_Surface *image) 
{
    //Free the image
    SDL_FreeSurface( image );
}

void quit_sdl()
{
    SDL_Quit();
}

图形管理器.h:

#ifndef GRAPHICSMANAGER_H
#define GRAPHICSMANAGER_H
#include <string>
#include<SDL.h>
class GraphicsManager
{
public:
    GraphicsManager();
    GraphicsManager(int SCREEN_WIDTH, int SCREEN_HEIGHT, int SCREEN_BPP, std::string caption, SDL_Surface *screen);
    virtual ~GraphicsManager();
    bool init(int SCREEN_WIDTH, int SCREEN_HEIGHT, int SCREEN_BPP, std::string caption, SDL_Surface *screen );
    SDL_Surface *load_image(std::string filename);
    void apply_surface( int x, int y, SDL_Surface* source, SDL_Surface* destination );
    void clean_up(SDL_Surface *image);
    void quit_sdl();
protected:
private:
};

#endif // GRAPHICSMANAGER_H

SDLLesson01.cpp:

#include "SDL/SDL.h"
#include "SDL/SDL_image.h"
#include <string>
#include "C:\Users\Chris Uzzolina\Desktop\obj\include\GraphicsManager.h"

int SCREEN_WIDTH = 640;
int SCREEN_HEIGHT = 480;
int SCREEN_BPP = 32;
SDL_Surface *message = NULL;
SDL_Surface *background = NULL;
SDL_Surface *screen = NULL;
std::string caption = "THProject";
SDL_Event event;

int main( int argc, char* args[] )
{
    bool quit=false;
    GraphicsManager grmanager();
    grmanager.init(SCREEN_WIDTH , SCREEN_HEIGHT , SCREEN_BPP , caption , screen);
    message = grmanager.load_image( "riku.bmp" );
    background = grmanager.load_image( "abc.bmp" );
    grmanager.apply_surface( 0, 0, background, screen );
    grmanager.apply_surface( 320, 0, background, screen );
    grmanager.apply_surface( 0, 240, background, screen );
    grmanager.apply_surface( 320, 240, background, screen );
    grmanager.apply_surface( 180, 140, message, screen );
    if( SDL_Flip( screen ) == -1 )
    {
        return 1;
    }
    while(quit==false)
    {
        while(SDL_PollEvent(&event))
        {
            if (event.type== SDL_QUIT)
            {
                quit=true;
            }
        }
    }
    grmanager.clean_up(message);
    grmanager.clean_up(background);
    grmanager.quit_sdl();
    return 0;
}

到目前为止，我已经在该网站上搜索了多个错误，并被最新的错误所困扰。如果有人能对这个问题提供一些见解，我们将不胜感激。我在运行 windows Vista 并使用 Code::Blocks 与 mingw 编译器和 SDL 库。这是构建消息:

C:\Users\Chris Uzzolina\Desktop\obj\SDLLesson01.cpp||In function 'int SDL_main(int, char**)':|
C:\Users\Chris Uzzolina\Desktop\obj\SDLLesson01.cpp|20|error: request for member 'init' in 'grmanager', which is of non-class type 'GraphicsManager()'|
C:\Users\Chris Uzzolina\Desktop\obj\SDLLesson01.cpp|21|error: request for member 'load_image' in 'grmanager', which is of non-class type 'GraphicsManager()'|
C:\Users\Chris Uzzolina\Desktop\obj\SDLLesson01.cpp|22|error: request for member 'load_image' in 'grmanager', which is of non-class type 'GraphicsManager()'|
C:\Users\Chris Uzzolina\Desktop\obj\SDLLesson01.cpp|23|error: request for member 'apply_surface' in 'grmanager', which is of non-class type 'GraphicsManager()'|
C:\Users\Chris Uzzolina\Desktop\obj\SDLLesson01.cpp|24|error: request for member 'apply_surface' in 'grmanager', which is of non-class type 'GraphicsManager()'|
C:\Users\Chris Uzzolina\Desktop\obj\SDLLesson01.cpp|25|error: request for member 'apply_surface' in 'grmanager', which is of non-class type 'GraphicsManager()'|
C:\Users\Chris Uzzolina\Desktop\obj\SDLLesson01.cpp|26|error: request for member 'apply_surface' in 'grmanager', which is of non-class type 'GraphicsManager()'|
C:\Users\Chris Uzzolina\Desktop\obj\SDLLesson01.cpp|27|error: request for member 'apply_surface' in 'grmanager', which is of non-class type 'GraphicsManager()'|
C:\Users\Chris Uzzolina\Desktop\obj\SDLLesson01.cpp|42|error: request for member 'clean_up' in 'grmanager', which is of non-class type 'GraphicsManager()'|
C:\Users\Chris Uzzolina\Desktop\obj\SDLLesson01.cpp|43|error: request for member 'clean_up' in 'grmanager', which is of non-class type 'GraphicsManager()'|
C:\Users\Chris Uzzolina\Desktop\obj\SDLLesson01.cpp|44|error: request for member 'quit_sdl' in 'grmanager', which is of non-class type 'GraphicsManager()'|
||=== Build finished: 11 errors, 0 warnings ===|