How to enhance OpenFileDialog() to choose folder instead of files

Question

How to enhance OpenFileDialog() to choose folder instead of files

Ajay Gera 45

Can we enhance OpenFileDialog() to choose folder instead of files?

Currently I am using FolderBrowserDialog dialog to select folder from the system using c#.

But I am looking, UI which is provided by OpenFileDialog as shown in attached file.

Or is there any other way to achieve UI similar to OpenFileDialog() in C#?

2 answers

Your answer

Answer 1

Michael Taylor 59,566

FolderBrowserDialog is the correct approach. It is standardized and is what WIndows users expect. You didn't really clarify why FolderBrowserDialog isn't what you want to use so I'm unclear what problem you're trying to solve by using the OpenFileDialog instead.

As for whether you can use OpenFileDialog instead, technically yes, it is just confusing. I use one app where I need to select a folder to scan. Their approach is to use the OpenFileDialog to have you select a file. Then they ignore the file you selected and just use the folder it was defined in. This is basically what you're asking for.

The problem with this approach is that it requires a user to have a file in the folder they want to select. Without a file then there is nothing to select which is what the OpenFileDialog requires. Whether that is an issue or not depends on your app.

You could also argue that you could use SaveFileDialog. The advantage here is that a file doesn't have to already exist. But the user will need to specify a (non-existent) file in order to dismiss the dialog.

Honestly, for consistency, you should stick with FolderBrowserDialog.

Ajay Gera 45 Reputation points

2025-05-19T05:58:43.57+00:00

The select/browse folder which gets launched from VS2022 by selecting

File -> Open -> Folder (from tool bar menu ) looks better and if C# application can launch this UI then application would look integrated with VS2022.

UI launch from FolderBrowserDialog looks outdated.

As per some thread, UI launched from FolderBrowserDialog in .net core is similar to when invoked File -> Open -> Folder from VS2022.
Michael Taylor 59,566 Reputation points

2025-05-19T14:00:16.2766667+00:00
What type of application do you have? The FolderBrowserDialog is a standard Win32 control that every application running on Windows that needs to show a folder dialog uses. It's UX is based upon the version of Windows you run it against. Here's proof they are identical.

One is generated by a basic Winforms app and the other is from VS. Other than the icon you can't tell the difference.

var dlg = new FolderBrowserDialog() { Description = "Browse", UseDescriptionForTitle = true, }; dlg.ShowDialog();

Please identify what issue(s) you're having with the dialog such that it isn't sufficient.
Ajay Gera 45 Reputation points

2025-05-19T14:31:30.75+00:00

Hi,

I am seeing following UX/dialog to select folders using FolderBrowserDialog on Windows 11 Enterprise Version 21H2.

I am not seeing UX as updated by you.

Is there any setting which needs to be done?

I am having C# application with Target framework .NET 4.8.
Ajay Gera 45 Reputation points

2025-05-19T14:45:36.3066667+00:00

Hi,

Please note, With my c# application on my m/c , I don't see UseDescriptionForTitle property defined on FolderBrowserDialog class.

I am using FolderBrowserDialog from System.Windows.Forms namespace.

Are you using FolderBrowserDialog from different namespace?

what version of System.Windows.Forms.dll you are using ? In other words from which location you added reference of System.Windows.Forms.dll in the project?
Michael Taylor 59,566 Reputation points

2025-05-19T15:03:04.3266667+00:00
OK so you're using NET 4.8 which is the older framework. What I showed you is how NET 6+ works with the modernized UI. Ideally upgrade your project to NET 8+ and then the dialog will be modern.

Since that may be a tall order right now then in the interim you can use the FolderDialogEx NuGet package which adds this modern UX to your existing NET 4.8 project. It requires that you add the NuGet package and then make a slight adjustment to the code to use the new dialog. Here's a version of the code that supports both NET 4.8 and NET 8+. The older framework uses the NuGet package the newer framework uses the builtin update.

private void openFolderToolStripMenuItem_Click ( object sender, EventArgs e ) { #if NETFRAMEWORK var dlg = new FolderBrowserEx.FolderBrowserDialog() { Title = "Browse", }; #else var dlg = new FolderBrowserDialog() { Description = "Browse", UseDescriptionForTitle = true, }; #endif dlg.ShowDialog(); }

Once you've updated your code to NET 8+ then you can remove the legacy code and package.
Castorix31 89,451 Reputation points

2025-05-19T15:10:11.3333333+00:00

The select/browse folder which gets launched from VS2022 by selecting File -> Open -> Folder (from tool bar menu ) looks better

As I said, it calls IFileDialog and FOS_PICKFOLDERS

Just do the same thing...
Ajay Gera 45 Reputation points

2025-05-19T18:46:05.0066667+00:00

@Michael Taylor , Thanks for the update.

I will try and update you.
Ajay Gera 45 Reputation points

2025-05-20T05:59:35.9233333+00:00

@Michael Taylor please note, FolderBrowserEx.dll from FolderBrowserEx is not a strongly named assembly, In our product , we can only use strongly named assembly.

Is there any other workaround/package which can be used to show modern browse dialog.

sn -T shows FolderBrowserEx.dll assembly is not strongly named assembly.

sn -T FolderBrowserEx.dll

Microsoft (R) .NET Framework Strong Name Utility Version 4.0.30319.0

Copyright (c) Microsoft Corporation. All rights reserved.

FolderBrowserEx.dll does not represent a strongly named assembly
Michael Taylor 59,566 Reputation points

2025-05-20T13:53:17.9466667+00:00

If it were me I'd forego the package and download the project from Github as mentioned here. Add the project to your solution and then add your signing cert to the project so it is signed like the rest of your code.

This, to me, is minimal effort to work around the issue until you upgrade to NET 8+. Then the project can be removed altogether.
Ajay Gera 45 Reputation points

2025-05-20T13:59:38.0333333+00:00

@Michael Taylor Thanks for the info

I am thinking to execute following with FolderBrowserEx.dll .

ildasm /all /out=FolderBrowserEx.il FolderBrowserEx.dll

ilasm /dll /key=<key.snk> FolderBrowserEx.il

I will get FolderBrowserEx.dll from the nuget package manager. After that I will add only FolderBrowserEx.dll to the project rather than adding reference of the package.
Michael Taylor 59,566 Reputation points

2025-05-20T14:05:03.29+00:00

I don't think pulling from NuGet and mucking with the DLL is clean or simple. Just copy the project into your solution and sign it like a normal project. That is one of the two ways the author suggests for using their code and it is simple. When you migrate to NET 8 then you just delete the project and everything should continue to compile normally.
Ajay Gera 45 Reputation points

2025-05-20T14:08:24.3133333+00:00

@Michael Taylor , I have tried the approach with ildasm , added FolderBrowserEx.dll as reference rather than package reference and seems to be working fine.

I just wanted to confirm if this approach would give any problem at later stage?

Answer 2

Castorix31 89,451

Or is there any other way to achieve UI similar to OpenFileDialog() in C#?

With IFileDialog and FOS_PICKFOLDERS

(I had posted a test sample in WinUI 3 C# (WinUI3_IFileDialog), nearly same code for WinForms)

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How to enhance OpenFileDialog() to choose folder instead of files

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