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有没有方法从fileprotocolhandler或url.dll获取错误级别?

rundll32 dll qt

Exa · 技术社区 · 14 年前

在我的某个程序中,我正在使用 rundll32.exe url.dll,FileProtocolHandler c:\path\to\a.file 打开文件。我想处理错误,以防这个文件无法打开,但我不知道如何找出是否有错误。这是我的密码:

QProcess::startDetached( QString( "rundll32.exe url.dll,FileProtocolHandler " + p_target_path ) );

startDetached() 现在总是返回true,因为它总是成功地打开包含rundll32.exe的进程。那么,我如何知道我的文件是否可以被找到/打开?

我在*.bat文件中尝试了错误级别的测试。

rundll32.exe url.dll,FileProtocolHandler c:\not_existing.exe >nul || echo Could not open file.

但没有什么可以回应。我还试图读取%errorlevel%,但即使文件不存在,errorlevel仍为0。

有人知道如何解决这个问题吗?

2 回复 | 直到 14 年前

Oleg 14 年前

在我看来rundll32.exe实际上不是返回erorlevel。你看 http://support.microsoft.com/kb/164787 可以看到,rundll32接口没有定义的返回错误的方法。

VOID CALLBACK FileProtocolHandler (
  __in  HWND hwnd,
  __in  HINSTANCE ModuleHandle,
  __in  PCTSTR pszCmdLineBuffer,
  __in  INT nCmdShow
);

顺便说一下,你可以调用函数 FileProtocolHandler 由url.dll直接导出,不启动rundll32.exe。AS pszCmdLineBuffer 你可以给 p_target_path . 不过,您不会收到任何错误信息。

更新的 :顺便说一下,如果你用 rundll32.exe url.dll,FileProtocolHandler 只打开文件而不打开您无法使用的URL ShellExecute 或 ShellExecuteEx 改为使用动词“open”或空(请参见 http://msdn.microsoft.com/en-us/library/bb776886.aspx )在最简单的情况下,代码可能如下所示

hinstance hinst=shellexecute(空,文本(“open”), 文本(“c:\path\to\a.file”),空,空,0);

你可以测试 hInst 有关错误(请参阅中的返回值 http://msdn.microsoft.com/en-us/library/bb762153.aspx )

Exa 14 年前

是的,甚至在你写评论之前,我就开始正确地阅读文档,不到2分钟我就找到了解决方案:

void main_window::open_test( QString p_target_path )
{
    p_target_path = p_target_path.remove( "\"" );

    HINSTANCE res = ShellExecute( NULL, TEXT("open"), (LPCWSTR) p_target_path.utf16(), NULL, NULL, SW_SHOWNORMAL );

    QString err_str = "";

    int res_code = (int) res;

    switch( res_code )
    {
    case 0:
        err_str = "Your operating system is out of memory or resources.";
        break;
    case ERROR_FILE_NOT_FOUND:
        err_str = "The specified file was not found.";
        break;
    case ERROR_PATH_NOT_FOUND:
        err_str = "The specified path was not found.";
        break;
    case ERROR_BAD_FORMAT:
        err_str = "The .exe file is invalid (non-Win32 .exe or error in .exe image).";
        break;
    case SE_ERR_ACCESSDENIED:
        err_str = "Your operating system denied access to the specified file.";
        break;
    case SE_ERR_ASSOCINCOMPLETE:
        err_str = "The file name association is incomplete or invalid.";
        break;
    case SE_ERR_DDEBUSY:
        err_str = "The DDE transaction could not be completed because other DDE transactions were being processed.";
        break;
    case SE_ERR_DDEFAIL:
        err_str = "The DDE transaction failed.";
        break;
    case SE_ERR_DDETIMEOUT:
        err_str = "The DDE transaction could not be completed because the request timed out.";
        break;
    case SE_ERR_DLLNOTFOUND:
        err_str = "The specified DLL was not found.";
        break;
    case SE_ERR_NOASSOC:
        err_str = "There is no application associated with the given file name extension.\nThis error will also be returned if you attempt to print a file that is not printable.";
        break;
    case SE_ERR_OOM:
        err_str = "There was not enough memory to complete the operation.";
        break;
    case SE_ERR_SHARE:
        err_str = "A sharing violation occurred.";
        break;
    default:
        return;
    }

    QMessageBox::warning( this, "Error", err_str );
}