Microsoft KB Archive/189094

= FIX: Calling CHttpFile::ErrorDlg Function Causes Errors 127 & 2 =

Article ID: 189094

Article Last Modified on 12/2/2003

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APPLIES TO


 * Microsoft Visual C++ 5.0 Enterprise Edition
 * Microsoft Visual C++ 5.0 Professional Edition
 * Microsoft Internet Explorer (Programming)
 * Microsoft Windows Internet Services (WinInet)

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This article was previously published under Q189094



SYMPTOMS
Calling CHttpFile::ErrorDlg results in one of the following error messages:

Error: (127) The specified procedure could not be found.

Error: (2) The system cannot find the file specified.



CAUSE
MFC attempts to call the Unicode or American National Standards Institute (ANSI) versions of most Win32 Internet Extensions (WinInet) functions when appropriate. In the case of the ErrorDlg function, MFC attempts to call the Unicode or ANSI version of the InternetErrorDlg function. For InternetErrorDlg, Unicode and ANSI versions are not necessary (no character data is passed in) and in fact, not available. When MFC attempts to call the Unicode or ANSI version of the function, the function is not found in the DLL.



RESOLUTION
It is possible to call the InternetErrorDlg function yourself. Following is a section of the Tear sample modified to do so: if (dwRet == HTTP_STATUS_DENIED) {      DWORD dwPrompt;

//dwPrompt = pFile->ErrorDlg(NULL,      //ERROR_INTERNET_INCORRECT_PASSWORD,       //FLAGS_ERROR_UI_FLAGS_GENERATE_DATA |       //FLAGS_ERROR_UI_FLAGS_CHANGE_OPTIONS, NULL);

LPVOID lpEmpty;

dwPrompt = ::InternetErrorDlg(GetDesktopWindow, *pFile,                                    ERROR_INTERNET_INCORRECT_PASSWORD,                                     FLAGS_ERROR_UI_FLAGS_GENERATE_DATA                                   | FLAGS_ERROR_UI_FLAGS_CHANGE_OPTIONS,                                     &lpEmpty);

if (dwPrompt != ERROR_INTERNET_FORCE_RETRY) ... In some cases, you may want different parameters for InternetErrorDlg. See the WinInet documentation for InternetErrorDlg and the MFC source code for CHttpFile::ErrorDlg. Note that you must change your project setting to link with wininet.lib in order to use InternetErrorDlg.



STATUS
Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This bug has been fixed in Visual C++ 6.0



MORE INFORMATION
When you run the MFC Internet Tear sample, an error is reported and the program fails if the site being accessed uses Basic Authentication without allowing anonymous access and with NTLM turned off.

It is also possible to collect the User Name and Password yourself and send a new request for data, as in the following example: if (dwRet == HTTP_STATUS_DENIED) {      cerr << "This page is password protected. " << endl; CHAR szUser[50]=""; CHAR szPass[50]="";

cerr << "User: "; cin >> szUser; // This should really not show the password on the screen. cerr << "Pass: "; cin >> szPass;

// You have to read all outstanding data on the Internet handle // before you can resubmit the request. Just discard the data.

CString strBuff; while (pFile->ReadString(strBuff)) {      }

pServer->SetOption(INTERNET_OPTION_USERNAME, szUser,                         lstrlen(szUser)); pServer->SetOption(INTERNET_OPTION_PASSWORD, szPass,                         lstrlen(szPass));

pFile->SendRequest; ... Notice that SetOption is being called on the CHttpConnection per the InternetSetOption documentation in Visual C++ which states the following:

Sets the user name associated with a handle returned by InternetConnect.

Calling SetOption on the CInternetSession will result in an Access violation in WinInet.dll.

