FolderBrowserDialog not showing folders

[Eric]

Hi,

I have created an application compiled with .NET 1.0. Since no folder dialog
was avialable i used an external library. Now that i'm using the .NET
framework 1.1 i removed the external library and used the
FolderBrowserDialog object. When a button is pressed i execute this code:

FolderBrowserDialog fbd = new FolderBrowserDialog ();
fbd.ShowDialog();

A Folder dialog is showed but i can't see any folders. The only thing i see
are the buttons OK & Cancel (and create new folder button when the
ShowNewFolderButton properyty is set to true). When i try the exact same
code on a different form everything is working fine. Any ideas??

Eric

 

[Peter Aragon]

Hi Eric

Are you using it from a form class?
If you use it straight from a class without a Hwnd then you will get that
kind of behaviour. Test is by adding a form, with a button, and put that
code in the onclick. You will see the folders now.

Good luck,
Peter

 

[DotNetJunkies User]

I'm experiencing a similar issue. A simple form program calling FolderBrowserDialog() works fine. However, when using the code in a larger program, no folders are displayed - only an empty dialog with <OK><Cancel> and <New Folder> buttons.

In both programs, the FolderBrowserDialog() is called by pressing a button on a form.

Any progress in finding a solution?

-Mark Falconer

 

[Herfried K. Wagner [MVP]]

I'm experiencing a similar issue. A simple form program calling FolderBrowserDialog() works fine. However, when using the code in a larger program, no folders are displayed - only an empty dialog with <OK><Cancel> and <New Folder> buttons.

In both programs, the FolderBrowserDialog() is called by pressing a button on a form.

Any progress in finding a solution?

Are you sure your 'Sub Main' or 'void Main' is marked with the
'STAThread' attribute and not with the 'MTAThread' attribute?

 

[DotNetJunkies User]

Specifying the threading model does not appear to make a difference. The simple code using FolderBrowserDialog() works with either [STAThread] or [MTAThread]. The larger program does not display files in the FolderBrowserDialog with either [STAThread] or [MTAThread].

-Mark Falconer

 

[Herfried K. Wagner [MVP]]

Mark,

Specifying the threading model does not appear to make a difference. The simple code using FolderBrowserDialog() works with either [STAThread] or [MTAThread]. The larger program does not display files in the FolderBrowserDialog with either [STAThread] or [MTAThread].

On my Windows XP Professional machine + .NET 1.1, specifying 'MTAThread'
prevents the folder selection control from showing. Are you using any
COM/ActiveX controls in your project? Do you see the folder selection
tree?

 

[DotNetJunkies User]

Herfried,

I've made some progress, but first to answer your questions:
1) The project uses a few Windows Forms Controls (Button, CheckBox, ComboBox, GroupBox, Label, ProgressBar, RadioButton, and StatusBar). I don't know if these contain ActiveX/COM technology.
2) When the FolderBrowserDialog 'fails', the folder selection tree is not visible.

I found the FolderBrowerDialog component works if the runtime library for linking is changed! Multi-threaded Debug (/MTd) does not work. Multi-threaded DLL (/MD or /MDd) does work!

Does this make sense?

Aside: Single-threaded (/ML or /MLd) runtime libraries cause a command line error ('/ML' and 'clr' options incompatible); and, the multi-threaded runtime library (/MT) causes several link errors.

Thanks much for your help.

Sincerely,

Mark Falconer

 

[Chris Lomont]

I have the same problems. Changing the link type fixed it also. This is
strange.

I am using Win XP corp, .NET 1.1, VS C++ 7.1 (2003).

Chris Lomont

Herfried,

I've made some progress, but first to answer your questions:
1) The project uses a few Windows Forms Controls (Button, CheckBox,

ComboBox, GroupBox, Label, ProgressBar, RadioButton, and StatusBar). I
don't know if these contain ActiveX/COM technology.

2) When the FolderBrowserDialog 'fails', the folder selection tree is not visible.

I found the FolderBrowerDialog component works if the runtime library for

linking is changed! Multi-threaded Debug (/MTd) does not work.
Multi-threaded DLL (/MD or /MDd) does work!

Does this make sense?

Aside: Single-threaded (/ML or /MLd) runtime libraries cause a command

line error ('/ML' and 'clr' options incompatible); and, the multi-threaded
runtime library (/MT) causes several link errors.

Thanks much for your help.

Sincerely,

Mark Falconer

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[Ken]

I experienced the same problem running on Windows 2003 Server Standard.
Explicitly defining the STAThread attribute in the void Main seems to
have solved the problem for me.