C++ 错误：不允许指向不完整类类型的指针。信用证++

因此，我是SDL新手，在我的代码中，我遇到了以下错误：

不允许指向不完整类类型的指针

代码如下：

main.cpp

events.cpp

---

编译events.cpp时会出现该错误，因为events.h在使用SDL数据类型之前不包含SDL.h。然后在events.cpp中，events.h之后包含SDL.h，因此出现错误。

SDL\u*ro；SDL_纹理*至；SDL_表面*so；SDL_窗口*wo；都是指向可能抽象类的未初始化指针。你的意思是不是创造一些事件，例如ev；然后调用SDL_FreeSurfaceev.getImage；？这完全是错误的。在使用SDL之前，你需要学习C++基础知识。在事件构造函数中，您将渲染器、纹理等创建为局部变量，当构造函数完成时，这些变量将超出范围。渲染器等的成员变量将被取消初始化。最后，在main函数中再次声明了它们，但从未向它们分配任何内容，并且正在从它们调用甚至不存在的函数。

#include <SDL.h>
#include "events.h"

int main(int argc, char ** argv)
{
SDL_Renderer* ro;
SDL_Texture* to;
SDL_Surface* so;
SDL_Window* wo;


SDL_FreeSurface(so->getImage());

SDL_SetRenderDrawColor(ro->getRenderer(), 255, 255, 255, 255); // error here

// handle events

events mo;
mo.handleEvents();

// cleanup SDL

SDL_DestroyTexture(to->getTexture()); // error here
SDL_DestroyRenderer(ro->getRenderer()); // error here
SDL_DestroyWindow(wo->getWindow()); // error here
SDL_Quit();

return 0;
}

#pragma once
class events
{
public:
events();
void handleEvents();
SDL_Renderer* getRenderer();
SDL_Texture* getTexture();
SDL_Surface* getImage();
SDL_Window* getWindow();
~events();
private:
SDL_Event event;
int x;
int y;
bool quit;
SDL_Renderer *renderer;
SDL_Texture *texture;
SDL_Surface *image;
SDL_Window *window;
};

#include "events.h"
#include <SDL.h>


events::events()
{
SDL_Event event;
int x = 288;
int y = 208;
bool quit = false;
SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, 0);
SDL_Texture *texture = SDL_CreateTextureFromSurface(renderer, image);
SDL_Surface *image = SDL_LoadBMP("face.bmp");
SDL_Window *window = SDL_CreateWindow("SDL2 Keyboard/Mouse events", SDL_WINDOWPOS_UNDEFINED,SDL_WINDOWPOS_UNDEFINED, 640, 480, 0);
}


events::~events()
{
}

void events::handleEvents(){

SDL_Init(SDL_INIT_VIDEO);

while (!quit)
{
    SDL_Delay(10);
    SDL_PollEvent(&event);

    switch (event.type)
    {
    case SDL_QUIT:
        quit = true;
        break;

    case SDL_KEYDOWN:
        switch (event.key.keysym.sym)
        {
        case SDLK_LEFT:
            x -= 5;
            break;
        case SDLK_RIGHT:
            x += 5;
            break;
        case SDLK_UP:
            y -= 5;
            break;
        case SDLK_DOWN:
            y += 5;
            break;
        }
        break;
    }

    SDL_Rect dstrect = { x, y, 64, 64 };

    SDL_RenderClear(renderer);
    SDL_RenderCopy(renderer, texture, NULL, &dstrect);
    SDL_RenderPresent(renderer);
  }
}

SDL_Renderer* events::getRenderer(){
return renderer;
}

SDL_Texture* events::getTexture(){
return texture;
}

SDL_Surface* events::getImage(){
return image;
}

SDL_Window* events::getWindow(){
return window;
}