怎么了?它和指针有关吗

我的WinMain是这样开始的:

int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, LPSTR lpCmdLine, int nShowCmd)
{
    if(SUCCEEDED(CoInitialize(NULL)))
    {
        {
            HRESULT hr = S_OK;
            Game game;
            D2DResources d2DResources;
            game.SetPointer(d2DResources);
            hr = d2DResources.Initialize(hInst);

我的编译器将执行上面最后显示的行，然后中断未处理的异常。我知道它不会走得更远，因为我在hr = d2DResources.Initialize(hInst)之前和之后添加了一个MessageBox命令，并且只有第一个显示。

所以，D2DResources:: initialize (HINSTANCE)是这样的:

HRESULT D2DResources::Initialize(HINSTANCE hInst)
{
    HRESULT hr;
    // Create factory
    hr = D2D1CreateFactory(D2D1_FACTORY_TYPE_SINGLE_THREADED, &pD2DFactory);
    // Create WIC factory
    if(SUCCEEDED(hr))
    {
        hr = CoCreateInstance(
            CLSID_WICImagingFactory,
            NULL,
            CLSCTX_INPROC_SERVER,
            IID_PPV_ARGS(&pIWICIF)
            );
    }
    // Create a window class
    WNDCLASSEX wClass;
    ZeroMemory(&wClass,sizeof(WNDCLASSEX));
    wClass.cbClsExtra=NULL;
    wClass.cbSize=sizeof(WNDCLASSEX);
    wClass.cbWndExtra=NULL;
    wClass.hbrBackground=(HBRUSH)COLOR_WINDOW;
    wClass.hCursor=LoadCursor(NULL,IDC_ARROW);
    wClass.hIcon=NULL;
    wClass.hIconSm=NULL;
    wClass.hInstance=hInst;
    wClass.lpfnWndProc=WinProc;
    wClass.lpszClassName="Window Class";
    wClass.lpszMenuName=NULL;
    wClass.style=CS_HREDRAW|CS_VREDRAW;
    if(!RegisterClassEx(&wClass))
    {
        int nResult=GetLastError();
        MessageBox(NULL,"Failed to register window class","Window Class Failed",MB_ICONERROR);
    }
    m_hWnd=CreateWindowEx(NULL,
            "Window Class",
            "Game", // Replace with gameName
            WS_OVERLAPPEDWINDOW|WS_MAXIMIZE,
            CW_USEDEFAULT,
            CW_USEDEFAULT,
            CW_USEDEFAULT,
            CW_USEDEFAULT,
            NULL,
            NULL,
            hInst,
            this);
    if(!m_hWnd)
    {
        int nResult=GetLastError();
        MessageBox(NULL,"Window class creation failed","Window Class Failed",MB_ICONERROR);
    }
    RECT rc;
    GetClientRect(m_hWnd,&rc);
    // Creates render target
    if(SUCCEEDED(hr))
    {
        pD2DFactory->CreateHwndRenderTarget(
            D2D1::RenderTargetProperties(),
            D2D1::HwndRenderTargetProperties(
                m_hWnd,
                D2D1::SizeU(
                    rc.right - rc.left,
                    rc.bottom - rc.top)),
                &pRT);
    }
    D2D1_SIZE_F pRTSize = pRT->GetSize();
    RECT rect = {50, (long)pRTSize.height-(LogLineSize*5), (long)pRTSize.width, (long)pRTSize.height};
    logArea = rect;
    if(SUCCEEDED(hr))
    {
        pRT->CreateSolidColorBrush(
            D2D1::ColorF(D2D1::ColorF::White),
            &pWhiteBrush
            );
    }
    if(SUCCEEDED(hr))
    {
        hr = DWriteCreateFactory(
            DWRITE_FACTORY_TYPE_SHARED,
            __uuidof(pWF),
            reinterpret_cast<IUnknown**>(&pWF)
            );
    }
    if(SUCCEEDED(hr))
    {
        hr = pWF->CreateTextFormat(
            L"Verdana",
            NULL,
            DWRITE_FONT_WEIGHT_NORMAL,
            DWRITE_FONT_STYLE_NORMAL,
            DWRITE_FONT_STRETCH_NORMAL,
            14.0f,
            L"",
            &pTextFormat
            );
    }
    return hr;
}

和重载的Game::SetPointer，在与D2DResources对象一起调用时看起来是这样的:

void Game::SetPointer(D2DResources& p)
{
    pD2DResources=&p;
}

pD2DResources是一个D2DResources*。

问题发生在D2DResources::Initialization(HINSTANCE)期间，当一个WM_SIZE消息被发送到我的WinProc。这里有一些我的WinProc:

LRESULT CALLBACK WinProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    if(msg==WM_CREATE)
    {
        LPCREATESTRUCT pcs = (LPCREATESTRUCT)lParam;
            Game* pGame = (Game*)pcs->lpCreateParams;
            ::SetWindowLongPtrW(
                hWnd,
                GWLP_USERDATA,
                PtrToUlong(pGame)
                );
    }
    else
    {
        Game* pGame = reinterpret_cast<Game*>(static_cast<LONG_PTR>(
            ::GetWindowLongPtrW(
                hWnd,
                GWLP_USERDATA
                )));
        switch(msg)
        {
        case WM_SIZE:
            {
                UINT width = LOWORD(lParam);
                UINT height = HIWORD(lParam);
                pGame->pD2DResources->OnResize(width, height);
            }
            break;

当OnResize被调用时，问题发生了

void D2DResources::OnResize(UINT width, UINT height)
{
    if(pRT)
    {
        HRESULT hr = pRT->Resize(D2D1::SizeU(width, height));
        if(hr!=0) MessageBox(NULL,"Render target could not be resized","ID2D1HwndRenterTarget Error",MB_ICONERROR);
    }
}

编译器中断，有一个黄色箭头指向if(pRT) (pRT是一个指向渲染目标的指针)行。

有趣的是，在调试过程中查看autos显示了这一点。

• this 0x00000000 {log=0x00000000 nLogLines=??logArea ={…} ．．．} D2DResources * const
• log 0x00000000 wchar_t [511]nLogLines CXX0030:错误:表达式无法求值
• logArea{顶级= ? ?底= ? ?左= ? ?= ? ?} tagRECTm_hWnd CXX0017:错误:符号"未找到pD2DFactory CXX0017:错误:没有找到符号"pIWICIF CXX0017:错误:符号"未找到pWF CXX0017:错误:符号"未找到pRT CXX0030:错误:表达式无法求值
  pCurrentScreen CXX0017:错误:符号"未找到pWhiteBrush CXX0017:错误:符号"未找到pTextFormat CXX0017:错误:符号"未找到

那么，问题是什么，解决办法是什么?