Explorer左侧面板中的ContextMenu Handler

Question

我正在尝试用c ++编写上下文菜单处理程序。我希望处理程序能够处理所有文件和所有文件夹，以及浏览器左窗格中的文件夹。我开始基于CodeProject项目，我正在努力适应我的需求。我是从here得到的。

到目前为止，除了Explorer左侧窗格的文件夹外，一切似乎都按预期工作。在那里我得到一个AccessViolationException。右键单击和上下文菜单的显示之间发生异常。我删除了不同函数中的代码，直到它再次工作，似乎问题来自QueryContextMenu方法。

有人知道我做错了什么吗？

这是我当前的代码有效（有点显而易见，因为没有添加任何项目）：

STDMETHODIMP ShellExt::Initialize (LPCITEMIDLIST pidlFolder, LPDATAOBJECT pDataObj, HKEY hProgID )
{
    FORMATETC fmt = { CF_HDROP, NULL, DVASPECT_CONTENT, -1, TYMED_HGLOBAL };
    STGMEDIUM stg = { TYMED_HGLOBAL };
    HDROP     hDrop;

    // Look for CF_HDROP data in the data object.
    if ( FAILED( pDataObj->GetData ( &fmt, &stg ) ))
    {
        // Nope! Return an "invalid argument" error back to Explorer.
        return E_INVALIDARG;
    }

    // Get a pointer to the actual data.
    hDrop = (HDROP) GlobalLock ( stg.hGlobal );

    // Make sure it worked.
    if ( NULL == hDrop )
        return E_INVALIDARG;

    // Sanity check - make sure there is at least one filename.
    UINT uNumFiles = DragQueryFile ( hDrop, 0xFFFFFFFF, NULL, 0 );
    HRESULT hr = S_OK;

    if ( 0 == uNumFiles )
    {
        GlobalUnlock ( stg.hGlobal );
        ReleaseStgMedium ( &stg );
        return E_INVALIDARG;
    }

    // Get the name of the first file and store it in our member variable m_szFile.
    if ( 0 == DragQueryFile ( hDrop, 0, m_szFile, MAX_PATH ) )
        hr = E_INVALIDARG;

    GlobalUnlock ( stg.hGlobal );
    ReleaseStgMedium ( &stg );

    return hr;
}

STDMETHODIMP ShellExt::QueryContextMenu (HMENU hmenu, UINT uMenuIndex, UINT uidFirstCmd, UINT uidLastCmd, UINT uFlags )
{
    return MAKE_HRESULT ( SEVERITY_SUCCESS, FACILITY_NULL, 0 );
}

STDMETHODIMP ShellExt::GetCommandString (UINT_PTR idCmd, UINT uFlags, UINT* pwReserved, LPSTR pszName, UINT cchMax)
{
    return E_INVALIDARG;
}

STDMETHODIMP ShellExt::InvokeCommand (LPCMINVOKECOMMANDINFO pCmdInfo)
{
    return S_OK;
}

但是现在如果我在ShellExt :: QueryContextMenu中添加一个项目，则Explorer的左侧窗格会抛出异常，而右侧窗格中的文件和文件夹会很好用。我尝试了我在互联网上找到的以下两个版本，但两者都有同样的问题：

STDMETHODIMP ShellExt::QueryContextMenu (HMENU hmenu, UINT uMenuIndex, UINT uidFirstCmd, UINT uidLastCmd, UINT uFlags )
{
    // If the flags include CMF_DEFAULTONLY then we shouldn't do anything.
    if ( uFlags & CMF_DEFAULTONLY )
        return MAKE_HRESULT ( SEVERITY_SUCCESS, FACILITY_NULL, 0 );

    InsertMenu ( hmenu, uMenuIndex, MF_BYPOSITION, uidFirstCmd, _T("Test Item") );

    return MAKE_HRESULT ( SEVERITY_SUCCESS, FACILITY_NULL, 1 );
}

和

STDMETHODIMP ShellExt::QueryContextMenu (HMENU hmenu, UINT uMenuIndex, UINT uidFirstCmd, UINT uidLastCmd, UINT uFlags )
{
    // If the flags include CMF_DEFAULTONLY then we shouldn't do anything.
    if ( uFlags & CMF_DEFAULTONLY )
        return MAKE_HRESULT ( SEVERITY_SUCCESS, FACILITY_NULL, 0 );

    UINT uID = uidFirstCmd;
    UINT pos = uMenuIndex;

    MENUITEMINFO mii = { sizeof(mii) };
    mii.fMask = MIIM_STRING | MIIM_FTYPE | MIIM_ID | MIIM_STATE;
    mii.fType = MFT_STRING;
    mii.dwTypeData = _T("Menu 1");
    mii.fState = MFS_ENABLED;
    mii.wID = uID++;

    if (!InsertMenuItem(hmenu, pos++, TRUE, &mii))
    {
        return HRESULT_FROM_WIN32(GetLastError());
    }

    return MAKE_HRESULT(SEVERITY_SUCCESS, FACILITY_NULL, uID - uidFirstCmd);
}

我在QueryContextMenu中得到的参数： - hmenu = 0x0000000001480405 - uMenuInde​​x = 3 - uidFirstCmd = 148 - uidLastCmd = 32762 - uFlags = 1044

例外细节。

QueryContextMenu和GetCommandString中的代码被执行。此异常发生在此之后，但仍然在contextmenu可见之前。不幸的是，细节对我来说并不是很重要：

explorer.exe中0x00007FF9B1C4C613（shell32.dll）抛出异常：0xC0000005：访问冲突读取位置0x00007FF9776D9868。发生了

堆栈跟踪：

shell32.dll!00007ff9b1c4c613()  
ExplorerFrame.dll!00007ff98d24993a()  
ExplorerFrame.dll!00007ff98d2c69a4()  
ExplorerFrame.dll!00007ff98d24de6c()  
ExplorerFrame.dll!00007ff98d251286()  
ExplorerFrame.dll!00007ff98d1fbad0()  
ExplorerFrame.dll!00007ff98d1ad5b3()  
ExplorerFrame.dll!00007ff98d180f2e()  
user32.dll!00007ff9b079ca66()  
user32.dll!00007ff9b079c34b()  
comctl32.dll!00007ff99d78b0da()  
comctl32.dll!00007ff99d78b017()  
ExplorerFrame.dll!00007ff98d187521()  
ExplorerFrame.dll!00007ff98d17d2e0()  
comctl32.dll!00007ff99d78b0da()  
comctl32.dll!00007ff99d78aef2()  
user32.dll!00007ff9b079ca66()  
user32.dll!00007ff9b079c34b()  
duser.dll!00007ff98106dff5()  
atlthunk.dll!00007ff983061208()  
user32.dll!00007ff9b079ca66()  
user32.dll!00007ff9b079c78c()  
user32.dll!00007ff9b07afa83()  
ntdll.dll!00007ff9b34833a4()  
win32u.dll!00007ff9b0071184()  
user32.dll!00007ff9b079bfbe()  
user32.dll!00007ff9b079be38()  
comctl32.dll!00007ff99d77a099()  
comctl32.dll!00007ff99d80b556()  
comctl32.dll!00007ff99d7b1302()  
user32.dll!00007ff9b079ca66()  
user32.dll!00007ff9b079c34b()  
comctl32.dll!00007ff99d78b0da()  
comctl32.dll!00007ff99d78b017()  
ExplorerFrame.dll!00007ff98d1bf33b()  
ExplorerFrame.dll!00007ff98d1bf27b()  
comctl32.dll!00007ff99d78b0da()  
comctl32.dll!00007ff99d78aef2()  
user32.dll!00007ff9b079ca66()  
user32.dll!00007ff9b079c582()  
ExplorerFrame.dll!00007ff98d1748a3()  
ExplorerFrame.dll!00007ff98d1747a9()  
ExplorerFrame.dll!00007ff98d1746f6()  
ExplorerFrame.dll!00007ff98d175a12()  
ExplorerFrame.dll!00007ff98d1870c2()  
windows.storage.dll!00007ff9af8db38c()  
windows.storage.dll!00007ff9af8db045()  
windows.storage.dll!00007ff9af8daf25()  
SHCore.dll!00007ff9b164c315()  
kernel32.dll!00007ff9b06281f4()  
ntdll.dll!00007ff9b344a251()

Answer 1

好像我解决了这个问题。我重新编写了项目的其余部分，即IClassFactory的实现以及shellextension类的IUnknown接口的实现，目的是了解该项目中这些“事物”的用途。

虽然这样做我发现了一些错误，未初始化的变量，转换为错误的类型等等。我还将一些计数器从UINT更改为LONG，以便我可以使用InterlockedIncrement而不是++。之后问题似乎消失了。我不知道究竟是什么bug导致了AccessViolationException，但最后它并没有像我想的那样在QueryContextMenu方法中......