C++ 对象类型错误

基本上由于某种原因，新对象的类型是错误的。所有源代码都在github上。如果有帮助，请随意用叉子叉

我有以下课程：

#ifndef _VIEW_HPP
#define _VIEW_HPP

#include <iostream>

#include "sfml_drawsurface.hpp"

class View {
protected:
    View(Drawsurface& d) : drawer(d) {
        std::clog << "View::View()" << std::endl;
    }

    Drawsurface& drawer;

    virtual void draw() = 0;
};


#endif

\ifndef\u视图\u水电站
#定义\u视图\u水电站
#包括
#包括“sfml_Drawsure.hpp”
类视图{
受保护的：
视图（绘图面和d）：抽屉（d）{
std:：clog看起来Mike的想法是正确的。从构造函数中的Program.cpp文件可以看出：

Program::Program() {
    Game game;
    ...
    this->gamecontroller = new Gamecontroller(game);  //Probably also bad

    sfml_drawsurface drawer(window);
    this->gameview = new Gameview(drawer);  
}

问题在于，构造函数完成后，
drawer
将不再存在，留给您一个悬而未决的引用和未定义的行为。看起来您可能在
game
变量上也有同样的问题

解决方案是不将它们作为局部变量，而是作为类成员（首选）或动态分配（这取决于您需要让它们存在多长时间）。
您的include-guard都是。我在这段代码中看到的唯一奇怪之处是，没有一个派生类析构函数被声明为虚拟的。我无法说明您为什么这样做（而且它太早了，咖啡因也不够，我记不清它是否重要）。最有可能的是，
drawer
在你调用
draw
之前超出了范围，留下了一个对被破坏对象的悬空引用
gameview
。你需要确保它和任何使用它的东西一样长。是的解决方案是将gamecontroller、game和gameview移出构造函数。现在我在创建新的pro时传递它们克对象。
/**
    * drawsurface base for all graphics pure abstract
    * provide only interface quite high-level
    * 2014/06/02
    * Juha Teurokoski
**/

#ifndef _DRAWSURFACE_HPP
#define _DRAWSURFACE_HPP

#include <string>

#include "../models/point.hpp"

class Drawsurface {
public:
    bool font_loaded;
    virtual void rectangleColor(Point& a, Point& b, unsigned int color) = 0;
    virtual void lineColor(Point& a, Point& b, unsigned int color) = 0;
    virtual void circleColor(Point& a, unsigned int rad, unsigned int color) = 0;
    virtual void trigonColor(Point& a, Point& b, Point& c, unsigned int color) = 0;
    virtual void trigonColor(Point& a, unsigned int size, unsigned int color) = 0;
    virtual void load_font(std::string font) = 0;

    virtual void draw_picture(std::string tiedosto, Point& a, bool center = false) = 0;
    virtual void draw_text(std::string text, Point& a, unsigned int color = 0) = 0;

    virtual int get_fontsize() = 0;
    virtual void flip() = 0;
    virtual void clear_screen() = 0;

    virtual ~Drawsurface() { }
};

#endif

#ifndef SFML_DRAWSURFACE_HPP
#define SFML_DRAWSURFACE_HPP
/**
    * sfml-drawsurface provides basic drawing, pictures and text
    * require drawsurface
    * 2014/06/02
    * Juha Teurokoski
**/

#include "drawsurface.hpp"

#include <vector>
#include <stdexcept>
#include <iostream>

#include <SFML/Graphics.hpp>

class sfml_drawsurface : public Drawsurface {
public:
    sfml_drawsurface(sf::RenderWindow& window);
    ~sfml_drawsurface();

    void rectangleColor(Point& a, Point& b, unsigned int color);
    void circleColor(Point& a, unsigned int rad, unsigned int color);
    void lineColor(Point& a, Point& b, unsigned int color);
    void trigonColor(Point& a, Point& b, Point& c, unsigned int color);
    void trigonColor(Point& a, unsigned int _size, unsigned int color);

    void draw_picture(std::string tiedosto, Point& a, bool center = false);
    void draw_text(std::string text, Point& a, unsigned int color);
    void load_font(std::string font);
    void clear_screen();

    int get_fontsize();
    void flip();
protected:
private:
    sf::RenderWindow& window;
    sf::Font font;

    sf::Color active;
    sf::Color normal;
};

#endif // SFML_DRAWSURFACE_HPP

sfml_drawsurface drawer(window);

this->gameview = new Gameview(drawer);
std::clog << typeid(drawer).name() << std::endl;

Program::Program() {
    Game game;
    ...
    this->gamecontroller = new Gamecontroller(game);  //Probably also bad

    sfml_drawsurface drawer(window);
    this->gameview = new Gameview(drawer);  
}