CException::GetErrorMessage
Call this member function to provide text about an error that has occurred.
virtual BOOL GetErrorMessage(
LPTSTR lpszError,
UINT nMaxError,
PUINT pnHelpContext = NULL
);
Parameters
lpszError
A pointer to a buffer that will receive an error message.nMaxError
The maximum number of characters the buffer can hold, including the NULL terminator.pnHelpContext
The address of a UINT that will receive the help context ID. If NULL, no ID will be returned.
Return Value
Nonzero if the function is successful; otherwise 0 if no error message text is available.
Remarks
For example, call GetErrorMessage to retrieve a string describing the error which caused MFC to throw a CFileException when writing to a CFile object.
Hinweis
GetErrorMessage will not copy more than nMaxError -1 characters to the buffer, and it will always add a trailing null to end the string. If the buffer is too small, the error message may be truncated.
Example
Here is an example of the use of CException::GetErrorMessage.
CFile fileInput;
CFileException ex;
// try to open a file for reading.
// The file will certainly not
// exist because there are too many explicit
// directories in the name.
// if the call to Open() fails, ex will be
// initialized with exception
// information. the call to ex.GetErrorMessage()
// will retrieve an appropriate message describing
// the error, and we'll add our own text
// to make sure the user is perfectly sure what
// went wrong.
if (!fileInput.Open(_T("\\Too\\Many\\Bad\\Dirs.DAT"), CFile::modeRead, &ex))
{
TCHAR szCause[255];
CString strFormatted;
ex.GetErrorMessage(szCause, 255);
// (in real life, it's probably more
// appropriate to read this from
// a string resource so it would be easy to
// localize)
strFormatted = _T("The data file could not be opened because of this error: ");
strFormatted += szCause;
AfxMessageBox(strFormatted);
}
else
{
// the file was opened, so do whatever work
// with fileInput
// we were planning...
fileInput.Close();
}
Requirements
Header: afx.h