Ookii-dialogs-wpf: Hanging unless run under debugger

Hey @matelich I'm not able to reproduce the hanging behavior you described.

Attached is a sample project of a WPF app using .NET 4.6.1 that opens the VistaFolderBrowserDialog using Ookii.Dialogs.Wpf v1.1.0 (_latest as of this writing_) and I was able to run a:

• Debug build _without_ the debugger attached
• Debug build _with_ the debugger attached
• Release build _without_ the debugger attached
• Release build _with_ the debugger attached

No hanging or exception occurred.

If you can provide me with a way of reproducing the hanging behavior, I'd be happy to investigate further.

The relevant code in the sample attached:

var dialog = new VistaFolderBrowserDialog
{
    Description = "Please select a folder.",
    UseDescriptionForTitle = true,
};

if (!VistaFolderBrowserDialog.IsVistaFolderDialogSupported)
{
    MessageBox.Show(this,
        "You are using an old Windows version. The regular folder browser dialog will open.",
        "Sample folder browser dialog");
}

if (dialog.ShowDialog(this).GetValueOrDefault(false))
{
    MessageBox.Show(this, "The selected folder was: " + dialog.SelectedPath,
        "Sample folder browser dialog");
}

• Repro_Hanging_Issue_11.zip

Thanks for getting back to me quickly, @augustoproiete. I did try various repro steps to explore things. Going to try to add more usage into my other WPF applications to see if there's some common factor that might identify why it doesn't work.

I threw some logging in and reproduced in my application, the hang is at int result = dialog.Show(owner); in private bool RunDialog(IntPtr owner)

seems related:
I'm experiencing slowness when the selected path is a long network path.

If I enable Native code debugging, I see that the most time is spent somewhere in this call stack:

win32u.dll!NtUserMsgWaitForMultipleObjectsEx

() Unknown
user32.dll!RealMsgWaitForMultipleObjectsEx() Unknown
shell32.dll!SHProcessMessagesUntilEventsEx() Unknown
shell32.dll!CChangeRouterProxy::RegisterThread() Unknown
shell32.dll!SHChangeNotifyRegisterThread
() Unknown
comdlg32.dll!CFileOpenSave::Show() Unknown
[Managed to Native Transition]
Ookii.Dialogs.Wpf.dll!Ookii.Dialogs.Wpf.VistaFolderBrowserDialog.RunDialog(System.IntPtr owner) Line 171 C#
Ookii.Dialogs.Wpf.dll!Ookii.Dialogs.Wpf.VistaFolderBrowserDialog.ShowDialog(System.Windows.Window owner) Line 157 C#
Ookii.Dialogs.Wpf.Sample.exe!Ookii.Dialogs.Wpf.Sample.MainWindow.ShowFolderBrowserDialog() Line 166 C#
Ookii.Dialogs.Wpf.Sample.exe!Ookii.Dialogs.Wpf.Sample.MainWindow._showDialogButton_Click(object sender, System.Windows.RoutedEventArgs e) Line 56 C#

or:

win32u.dll!00007ff9d17c9164()   Unknown
user32.dll!00007ff9d2ca059d()   Unknown
shell32.dll!SHProcessMessagesUntilEventsEx()    Unknown
shell32.dll!CChangeRouterProxy::RegisterThread()    Unknown
shell32.dll!SHChangeNotifyRegisterThread()  Unknown
comdlg32.dll!CFileOpenSave::Show()  Unknown
[Managed to Native Transition]  
Ookii.Dialogs.Wpf.dll!Ookii.Dialogs.Wpf.VistaFolderBrowserDialog.RunDialog(System.IntPtr owner) Line 171    C#
Ookii.Dialogs.Wpf.dll!Ookii.Dialogs.Wpf.VistaFolderBrowserDialog.ShowDialog(System.Windows.Window owner) Line 157   C#
Ookii.Dialogs.Wpf.Sample.exe!Ookii.Dialogs.Wpf.Sample.MainWindow.ShowFolderBrowserDialog() Line 166 C#
Ookii.Dialogs.Wpf.Sample.exe!Ookii.Dialogs.Wpf.Sample.MainWindow._showDialogButton_Click(object sender, System.Windows.RoutedEventArgs e) Line 56   C#

or:

ntdll.dll!RtlpHashStringToAtom()    Unknown
ntdll.dll!RtlpFreeAllAtom

() Unknown
ntdll.dll!RtlpDereferenceAtom() Unknown
ntdll.dll!RtlDeleteAtomFromAtomTable() Unknown
kernel32.dll!InternalDeleteAtom
() Unknown
dui70.dll!DirectUI::Value::_ZeroRelease() Unknown
dui70.dll!DirectUI::DUIXmlParser::_DestroyTables(void) Unknown
dui70.dll!DirectUI::DUIXmlParser::~DUIXmlParser() Unknown
dui70.dll!DirectUI::DUIXmlParser::`vector deleting destructor'() Unknown
dui70.dll!DirectUI::AccHDelete(class DirectUI::RefcountBase *) Unknown
shell32.dll!_DUI_ShellStyleSheet_UninitThreadIfPossible(void) Unknown
shell32.dll!DUI_ShellStyleSheet_UninitThread(void) Unknown
shell32.dll!CDUIViewFrame::DestroyFrameWindow(void) Unknown
shell32.dll!CExplorerBrowser::_CleanupFrame(void) Unknown
shell32.dll!CExplorerBrowser::Destroy() Unknown
comdlg32.dll!CFileOpenSave::_OnDestroyDialog() Unknown
comdlg32.dll!CFileOpenSave::s_OpenSaveDlgProc() Unknown
user32.dll!UserCallDlgProcCheckWow() Unknown
user32.dll!DefDlgProcWorker() Unknown
user32.dll!DefDlgProcW
() Unknown
user32.dll!UserCallWinProcCheckWow() Unknown
user32.dll!DispatchClientMessage() Unknown
user32.dll!__fnDWORD
() Unknown
ntdll.dll!KiUserCallbackDispatcherContinue
() Unknown
win32u.dll!NtUserDestroyWindow
() Unknown
user32.dll!DialogBox2() Unknown
user32.dll!InternalDialogBox() Unknown
user32.dll!DialogBoxIndirectParamAorW
() Unknown
user32.dll!DialogBoxIndirectParamW
() Unknown
comdlg32.dll!CFileOpenSave::Show() Unknown
[Managed to Native Transition]
Ookii.Dialogs.Wpf.dll!Ookii.Dialogs.Wpf.VistaFolderBrowserDialog.RunDialog(System.IntPtr owner) Line 171 C#
Ookii.Dialogs.Wpf.dll!Ookii.Dialogs.Wpf.VistaFolderBrowserDialog.ShowDialog(System.Windows.Window owner) Line 157 C#
Ookii.Dialogs.Wpf.Sample.exe!Ookii.Dialogs.Wpf.Sample.MainWindow.ShowFolderBrowserDialog() Line 166 C#
Ookii.Dialogs.Wpf.Sample.exe!Ookii.Dialogs.Wpf.Sample.MainWindow._showDialogButton_Click(object sender, System.Windows.RoutedEventArgs e) Line 56 C#