Prev: Maximize 'off-centre'
Next: Programmatically create an "Add Schedule Task"
From: Vanja on 19 Apr 2010 04:56
Hello,

Does someone know why the CFileDialog throws CInvalidArgException if
"recycled" (DoModal called the second time)? The problem happens only on
Vista und Windows 7, and only if using bVistaSyle==TRUE. Creating the dialog
with bVistaStyle==FALSE solves the problem, but it's a poor solution. Also,
if file filters are not used, no exception occurs.

Here's the code (more or less the same example like in MSDN):

// szFilters is a text string that includes two file name filters:
// "*.my" for "MyType Files" and "*.*' for "All Files."
TCHAR szFilters[]= _T("MyType Files (*.my)|*.my|All Files (*.*)|*.*||");

// Create an Open dialog; the default file name extension is ".my".
CFileDialog fileDlg(TRUE, _T("my"), _T("*.my"),
OFN_FILEMUSTEXIST | OFN_HIDEREADONLY, szFilters, NULL, 0,
/*bVistaStyle*/ TRUE);

// first time -> ok
fileDlg.DoModal();

// second time -> not so ok (CInvalidArgException thrown)
// If the dialog was created with szFilters==NULL, no problems.
// If the dialog was created with bVistaStyle==FALSE, no problems.
fileDlg.DoModal();


Stack at the point of exception (first-chance) is:

mfc90ud.dll!AfxThrowInvalidArgException() Line 233
mfc90ud.dll!CFileDialog::ApplyOFNToShellDialog() Line 388
mfc90ud.dll!CFileDialog::DoModal() Line 706
CommonDialog_Test.exe!CCommonDialog_TestDlg::OnBnClickedBtnOpentwice()
Line 142
. . . .

I could easily circumvent the problem by always creating a fresh instance of
CFileDialog. But since the file-browser is required many times in my
application, my intention was to create it once, re-use it and thus improve
the reaction time.

Thanks in advance.
From: Alexandre Grigoriev on 20 Apr 2010 00:15
Creation of CFileDialog is very inexpensive operation. You don't gain
anything by reusing it. DoModal itself is much more expensive.

"Vanja" <Vanja(a)discussions.microsoft.com> wrote in message
news:BEF69A5E-CD82-46DB-A62B-9154164791CD(a)microsoft.com...
> Hello,
>
> Does someone know why the CFileDialog throws CInvalidArgException if
> "recycled" (DoModal called the second time)? The problem happens only on
> Vista und Windows 7, and only if using bVistaSyle==TRUE. Creating the
> dialog
> with bVistaStyle==FALSE solves the problem, but it's a poor solution.
> Also,
> if file filters are not used, no exception occurs.
>
> Here's the code (more or less the same example like in MSDN):
>
> // szFilters is a text string that includes two file name filters:
> // "*.my" for "MyType Files" and "*.*' for "All Files."
> TCHAR szFilters[]= _T("MyType Files (*.my)|*.my|All Files (*.*)|*.*||");
>
> // Create an Open dialog; the default file name extension is ".my".
> CFileDialog fileDlg(TRUE, _T("my"), _T("*.my"),
> OFN_FILEMUSTEXIST | OFN_HIDEREADONLY, szFilters, NULL, 0,
> /*bVistaStyle*/ TRUE);
>
> // first time -> ok
> fileDlg.DoModal();
>
> // second time -> not so ok (CInvalidArgException thrown)
> // If the dialog was created with szFilters==NULL, no problems.
> // If the dialog was created with bVistaStyle==FALSE, no problems.
> fileDlg.DoModal();
>
>
> Stack at the point of exception (first-chance) is:
>
> mfc90ud.dll!AfxThrowInvalidArgException() Line 233
> mfc90ud.dll!CFileDialog::ApplyOFNToShellDialog() Line 388
> mfc90ud.dll!CFileDialog::DoModal() Line 706
> CommonDialog_Test.exe!CCommonDialog_TestDlg::OnBnClickedBtnOpentwice()
> Line 142
> . . . .
>
> I could easily circumvent the problem by always creating a fresh instance
> of
> CFileDialog. But since the file-browser is required many times in my
> application, my intention was to create it once, re-use it and thus
> improve
> the reaction time.
>
> Thanks in advance.

 | 
Pages: 1
Prev: Maximize 'off-centre'
Next: Programmatically create an "Add Schedule Task"