Question

当我使用

编译以下代码（使用Visual C ++ 2010 Express）时

cl test.cpp

并运行.exe，然后关闭Windows 7，我收到如下错误消息：

The instruction 0x00f....9 in explorer.exe cannot access memory at 0x00000000. Memory cannot be read.

我在以下代码中尝试了很多修改，但无法解决此问题。 另一句话：我确定这个程序导致崩溃：我没有运行它，没有关机错误消息，如果我运行它，就有一个。

崩溃的原因是什么？

Source file downloadable here

#pragma comment(lib, "user32.lib")
#define UNICODE
#include <windows.h>

LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    return DefWindowProc(hwnd, uMsg, wParam, lParam);
}

int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE, PWSTR pCmdLine, int nCmdShow)
{
    const wchar_t CLASS_NAME[]  = L"Sample Window Class";
    WNDCLASS wc = { };
    wc.lpfnWndProc   = WindowProc;
    wc.hInstance     = hInstance;
    wc.lpszClassName = CLASS_NAME;
    RegisterClass(&wc);

    HWND hwndMain = CreateWindowEx(WS_EX_TOOLWINDOW | WS_EX_LAYERED, wc.lpszClassName, 0, WS_POPUP | WS_VISIBLE | WS_SYSMENU, 0, 0, 300, 300, 0, 0, 0, 0);
    SetLayeredWindowAttributes(hwndMain, 0, 192, LWA_ALPHA);
    ShowWindow(hwndMain, nCmdShow);

    // without the next 2 lines, no crash at shutdown
    // but these 2 next lines are really important to make the main 
    // window part of the windows' desktop    
    // see comments on http://stackoverflow.com/a/27787003/1422096
    HWND hwndOwner = GetWindow(GetWindow(GetTopWindow(0), GW_HWNDLAST), GW_CHILD);   
    SetWindowLong(hwndMain, GWL_HWNDPARENT, (LONG) hwndOwner);      

    MSG msg = { };
    while (GetMessage(&msg, NULL, 0, 0) > 0)
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return 0;
}

关机时出现错误信息

0 个答案: