如何创建和解析快捷方式

引言

快捷方式是具有.lnk扩展名的文件。这些文件中的每一个都包含一个特殊的COM对象，指向另一个文件。通常，当你尝试打开一个.lnk文件时，系统会打开该快捷方式指向的文件。

让我们做一个实验。在某个地方创建一个文本文件（具有.txt扩展名的文件）。然后创建一个指向该文件的快捷方式（如果你不知道如何手动创建快捷方式，请给我发送私人电子邮件）。然后尝试使用Microsoft Word打开该快捷方式，使用文件->打开命令并仅选择刚刚创建的快捷方式。MS Word会正确执行：它将打开该快捷方式指向的文本文件。现在使用记事本执行相同的操作。你将看到乱码，而不是文本文件的内容。这意味着记事本不知道如何处理快捷方式。

因此我们得出结论：在Windows中，程序必须内置对快捷方式的支持，才能正确处理它们。

在本文中，我将展示如何做到这一点。我将展示两个函数：如何创建和解析快捷方式。代码注释良好（我认为）并且不言自明。

代码

/**********************************************************************
* Function......: CreateShortcut
* Parameters....: lpszFileName - string that specifies a valid file name
*          lpszDesc - string that specifies a description for a 
                             shortcut
*          lpszShortcutPath - string that specifies a path and 
                                     file name of a shortcut
* Returns.......: S_OK on success, error code on failure
* Description...: Creates a Shell link object (shortcut)
**********************************************************************/
HRESULT CreateShortcut(/*in*/ LPCTSTR lpszFileName, 
                    /*in*/ LPCTSTR lpszDesc, 
                    /*in*/ LPCTSTR lpszShortcutPath)
{
    HRESULT hRes = E_FAIL;
    DWORD dwRet = 0;
    CComPtr<IShellLink> ipShellLink;
        // buffer that receives the null-terminated string 
        // for the drive and path
    TCHAR szPath[MAX_PATH];    
        // buffer that receives the address of the final 
        //file name component in the path
    LPTSTR lpszFilePart;    
    WCHAR wszTemp[MAX_PATH];
        
    // Retrieve the full path and file name of a specified file
    dwRet = GetFullPathName(lpszFileName, 
                       sizeof(szPath) / sizeof(TCHAR), 
                       szPath, &lpszFilePart);
    if (!dwRet)                                        
        return hRes;

    // Get a pointer to the IShellLink interface
    hRes = CoCreateInstance(CLSID_ShellLink,
                            NULL, 
                            CLSCTX_INPROC_SERVER,
                            IID_IShellLink,
                            (void**)&ipShellLink);

    if (SUCCEEDED(hRes))
    {
        // Get a pointer to the IPersistFile interface
        CComQIPtr<IPersistFile> ipPersistFile(ipShellLink);

        // Set the path to the shortcut target and add the description
        hRes = ipShellLink->SetPath(szPath);
        if (FAILED(hRes))
            return hRes;

        hRes = ipShellLink->SetDescription(lpszDesc);
        if (FAILED(hRes))
            return hRes;

        // IPersistFile is using LPCOLESTR, so make sure 
                // that the string is Unicode
#if !defined _UNICODE
        MultiByteToWideChar(CP_ACP, 0, 
                       lpszShortcutPath, -1, wszTemp, MAX_PATH);
#else
        wcsncpy(wszTemp, lpszShortcutPath, MAX_PATH);
#endif

        // Write the shortcut to disk
        hRes = ipPersistFile->Save(wszTemp, TRUE);
    }

    return hRes;
}

/*********************************************************************
* Function......: ResolveShortcut
* Parameters....: lpszShortcutPath - string that specifies a path 
                                     and file name of a shortcut
*          lpszFilePath - string that will contain a file name
* Returns.......: S_OK on success, error code on failure
* Description...: Resolves a Shell link object (shortcut)
*********************************************************************/
HRESULT ResolveShortcut(/*in*/ LPCTSTR lpszShortcutPath,
                        /*out*/ LPTSTR lpszFilePath)
{
    HRESULT hRes = E_FAIL;
    CComPtr<IShellLink> ipShellLink;
        // buffer that receives the null-terminated string 
        // for the drive and path
    TCHAR szPath[MAX_PATH];     
        // buffer that receives the null-terminated 
        // string for the description
    TCHAR szDesc[MAX_PATH]; 
        // structure that receives the information about the shortcut
    WIN32_FIND_DATA wfd;    
    WCHAR wszTemp[MAX_PATH];

    lpszFilePath[0] = '\0';

    // Get a pointer to the IShellLink interface
    hRes = CoCreateInstance(CLSID_ShellLink,
                            NULL, 
                            CLSCTX_INPROC_SERVER,
                            IID_IShellLink,
                            (void**)&ipShellLink); 

    if (SUCCEEDED(hRes)) 
    { 
        // Get a pointer to the IPersistFile interface
        CComQIPtr<IPersistFile> ipPersistFile(ipShellLink);

        // IPersistFile is using LPCOLESTR, 
                // so make sure that the string is Unicode
#if !defined _UNICODE
        MultiByteToWideChar(CP_ACP, 0, lpszShortcutPath,
                                       -1, wszTemp, MAX_PATH);
#else
        wcsncpy(wszTemp, lpszShortcutPath, MAX_PATH);
#endif

        // Open the shortcut file and initialize it from its contents
        hRes = ipPersistFile->Load(wszTemp, STGM_READ); 
        if (SUCCEEDED(hRes)) 
        {
            // Try to find the target of a shortcut, 
                        // even if it has been moved or renamed
            hRes = ipShellLink->Resolve(NULL, SLR_UPDATE); 
            if (SUCCEEDED(hRes)) 
            {
                // Get the path to the shortcut target
                hRes = ipShellLink->GetPath(szPath, 
                                     MAX_PATH, &wfd, SLGP_RAWPATH); 
                if (FAILED(hRes))
                    return hRes;

                // Get the description of the target
                hRes = ipShellLink->GetDescription(szDesc,
                                             MAX_PATH); 
                if (FAILED(hRes))
                    return hRes;

                lstrcpyn(lpszFilePath, szPath, MAX_PATH); 
            } 
        } 
    } 

    return hRes;
}

使用代码

以下代码将展示如何使用这些函数。

void HowToCreateShortcut()
{
    LPCTSTR lpszFileName = _T("C:\\Work\\Window.exe");
    LPCTSTR lpszShortcutDesc = _T("Anything can go here");
    LPCTSTR lpszShortcutPath = 
_T("C:\\Documents and Settings\\Administrator\\Desktop\\Sample Shortcut.lnk");

    CreateShortcut(lpszFileName, lpszShortcutDesc, lpszShortcutPath);
}

void HowToResolveShortcut()
{
    LPCTSTR lpszShortcutPath = 
_T("C:\\Documents and Settings\\Administrator\\Desktop\\Sample Shortcut.lnk");
    TCHAR szFilePath[MAX_PATH];

    ResolveShortcut(lpszShortcutPath, szFilePath);
}

就是这样。