How do you configure an OpenFileDialog to select folders?

In VS .NET, when you are selecting a folder for a project, a dialog that looks like an OpenFileDialog or SaveFileDialog is displayed, but is set up to accept only folders. Ever since I've seen this I've wanted to know how it's done. I am aware of the FolderBrowserDialog, but I've never really liked that dialog. It starts too small and doesn't let me take advantage of being able to type a path.

I'm almost certain by now there's not a way to do this from .NET, but I'm just as curious how you do it from unmanaged code as well. Short of completely reimplementing the dialog from scratch, how do you modify the dialog to have this behavior?

I'd also like to restate that I am aware of the FolderBrowserDialog but sometimes I don't like to use it, in addition to being genuinely curious how to configure a dialog in this manner. Telling me to just use the FolderBrowserDialog helps me maintain a consistent UI experience but doesn't satisfy my curiosity so it won't count as an answer.

It's not a Vista-specific thing either; I've been seeing this dialog since VS .NET 2003, so it is doable in Win2k and WinXP. This is less of a "I want to know the proper way to do this" question and more of a "I have been curious about this since I first wanted to do it in VS 2003" question. I understand that Vista's file dialog has an option to do this, but it's been working in XP so I know they did something to get it to work. Vista-specific answers are not answers, because Vista doesn't exist in the question context.

Update: I'm accepting Scott Wisniewski's answer because it comes with a working sample, but I think Serge deserves credit for pointing to the dialog customization (which is admittedly nasty from .NET but it does work) and Mark Ransom for figuring out that MS probably rolled a custom dialog for this task.

Solution 1:

I have a dialog that I wrote called an OpenFileOrFolder dialog that allows you to open either a folder or a file.

If you set its AcceptFiles value to false, then it operates in only accept folder mode.

You can download the source from GitHub here

Solution 2:

There is the Windows API Code Pack. It's got a lot of shell related stuff, including the CommonOpenFileDialog class (in the Microsoft.WindowsAPICodePack.Dialogs namespace). This is the perfect solution - the usual open dialog with only folders displayed.

Here is an example of how to use it:

CommonOpenFileDialog cofd = new CommonOpenFileDialog();
cofd.IsFolderPicker = true;
cofd.ShowDialog();

Unfortunately Microsoft no longer ships this package, but several people have unofficially uploaded binaries to NuGet. One example can be found here. This package is just the shell-specific stuff. Should you need it, the same user has several other packages which offer more functionality present in the original package.

Solution 3:

You can use FolderBrowserDialogEx - a re-usable derivative of the built-in FolderBrowserDialog. This one allows you to type in a path, even a UNC path. You can also browse for computers or printers with it. Works just like the built-in FBD, but ... better.

(EDIT: I should have pointed out that this dialog can be set to select files or folders. )

Full Source code (one short C# module). Free. MS-Public license.

Code to use it:

var dlg1 = new Ionic.Utils.FolderBrowserDialogEx();
dlg1.Description = "Select a folder to extract to:";
dlg1.ShowNewFolderButton = true;
dlg1.ShowEditBox = true;
//dlg1.NewStyle = false;
dlg1.SelectedPath = txtExtractDirectory.Text;
dlg1.ShowFullPathInEditBox = true;
dlg1.RootFolder = System.Environment.SpecialFolder.MyComputer;

// Show the FolderBrowserDialog.
DialogResult result = dlg1.ShowDialog();
if (result == DialogResult.OK)
{
    txtExtractDirectory.Text = dlg1.SelectedPath;
}

Solution 4:

The Ookii.Dialogs package contains a managed wrapper around the new (Vista-style) folder browser dialog. It also degrades gracefully on older operating systems.

• Ookii Dialogs for WPF targetting .NET 4.5 and available on NuGet
• Ookii Dialogs for Windows Forms targetting .NET 4.5 and available on NuGet