-5

创建对对象的引用会导致该引用被破坏。这绝对是奇怪的，因为它似乎是简单的 C++ 功能。另一个奇怪的事情是，问题似乎已经出现而没有更改任何相关代码（我知道）。如果我不得不猜测，我会说这与所涉及的 DirectX 代码有关。

这是代码：

// the header file of the class of the problem object
#pragma once

#include<vector>
#include<Windows.h>
#include<xnamath.h>
#include<string>
using namespace std;

#define float2 XMFLOAT2
#define float4 XMFLOAT4

namespace DXLib
{
    struct Sprite
    {
        char* imagename;
        float2 pos;
        float rot;
        float2 scale;
        float4 rgba;
    };

    struct Rect
    {
        float2 pos;
        float2 size;
        float4 color;
    };

    struct Text
    {
        std::string string;
        float2 pos;
    };

    class D3DDraw
    {
    public:
        D3DDraw(int maxdepth = 0);
        ~D3DDraw(void);
        void DrawSprite(char* imagename, float2 pos, int depth = 0, float rot = 0.0f, XMFLOAT2 scale = XMFLOAT2(1, 1), float4 rgba = float4(1, 1, 1, 1));
        //void DrawRect(float2 pos, float2 size, float4 color);
        void DrawDXText(std::string string, float2 pos);
        void Clear(void);

    public:
        std::vector<vector<Sprite>> depths_;
        std::vector<Text> texts_;
        int maxdepth_;  // set on initialize, do not change
        float2 spriteoffset_;
    };
}


// the header file for the base class for the class in which the problem occurs
#pragma once
#include <windows.h>
#include"D3DCore.h"
#include"D3DRender.h"
#include"D3DDraw.h"
#include"DXInput.h"
#include<cassert>
using namespace DXLib;


const UINT uWindowSizeX = 1000;
const UINT uWindowSizeY = 800;


class Application
{
public:
    Application();
    ~Application();
    HRESULT Run();

protected:
    virtual void Update(void);

private:
    static LRESULT CALLBACK WndProc( HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam );

protected:
    D3DDraw m_cDraw;
    DXInput m_cInput;

private:
    HWND m_hWnd;
    D3DCore m_cCore;
    D3DRender m_cRender;
};


// the class header file
#pragma once
#include"stdafx.h"
#include"VGraphics.h"
#include"EntityPool.h"
#include"VUI.h"
#include"Manager.h"

class VApp : public Application
{
public:
    VApp(void);
    ~VApp(void);
    virtual void Update(void) override;

private:
    void Log(double dTime);  // prints log info to console every nth frame

private:
    int m_iTime;
    VGraphics m_cGraphics;
    EntityPool m_cPool;
    VUI m_cVUI;
    Manager m_cManager;
};


// the function in which the problem occurs
void VApp::Update(void)
{
    double dTime = (GetTickCount() - m_iTime) / 1000.0;

    D3DDraw& rcDraw = m_cDraw; // that object is initialized and just fine
    // that reference now points to an uninitialized object
    m_cVUI.Tick(m_cInput, m_cDraw, m_cPool, m_cManager);

    m_cManager.Tick();

    m_cGraphics.Draw(m_cVUI.GetView(), m_cPool, m_cDraw);

    Log(dTime);

    m_iTime = GetTickCount();
    Sleep(15);
}
4

2 回答 2

0

我不知道为什么，但在这里更改访问说明符：

protected:
    D3DDraw m_cDraw;
    DXInput m_cInput;

为了public解决这个问题，这是一个黑客，但我可以接受：D

无论如何感谢您尝试提供帮助

于 2013-02-22T21:58:40.020 回答
0

好吧，这是我对 SSCCE 的尝试，但我无法让它失败（可能与通过指向错误对象的指针访问受保护的成员有关）：

class Thing 
{ 
public:
    int value;
    Thing() { value = 42; }
    ~Thing() { };
};

class Foo
{
public:
    Foo() { }
    ~Foo() { }

public:
    void CallMethod()
    {
        Method();
    }

protected:
    virtual void Method()
    {
    }

    Thing m_x;
};

class Bar : public Foo
{
public:
    Bar() { }
    ~Bar() { }

    virtual void Method() override
    {
        Thing& x = m_x;
        printf("%d\n", x.value);
    }
};

int _tmain(int argc, _TCHAR* argv[])
{
    Foo f;
    Foo& rf = f;

    printf("%p\n", &rf);

    Bar bar;

    Foo& rfoo = bar;
    rfoo.CallMethod();

    return 0;
}
于 2013-02-22T22:25:18.660 回答