Using a CommonOpenFileDialog to select a folder but still show files within the folder in Windows 10

Question

I'm trying to use CommonOpenFileDialog to allow users to select a folder, but also view the files that within the folder in the dialog. Currently my code allows the user to only select a folder, but files within it are hidden, which causes users to think they have selected a wrong (empty) folder.

using (var dlg = new CommonOpenFileDialog()
{
    Title = "Select folder to import from",
    AllowNonFileSystemItems = true,
    IsFolderPicker = true,
    EnsurePathExists = true,
    Multiselect = false,
    ShowPlacesList = true
})
{
    if (dlg.ShowDialog() == CommonFileDialogResult.Ok)
    {
        //Do things with the selected folder and the files within it...
    }
}

How can I achieve my goal for applications targeting Windows 10?

_{NOTE: There is a very similar question titled "How can I make CommonOpenFileDialog select folders only, but still show files?". This question already has good answers, however, none of the solutions work in Windows 10. Because the existing question is outdated (asked over 9 years ago) and doesn't apply for Windows 10, this question is specifically asking for a solution that works on a Windows 10 device.}

I sympathize with your dilemma. Without rolling your own dialog, it appears this may not be doable using the common dialogs in Windows 10. Have you considered using the `OpenFileDialog`, forcing the user “pick” one of the displayed files in the folder they want, then only use the folder path after that? I can post code for this, however it is simply an `OpenFileDialog` that uses… `string dir = Path.GetDirectoryName(dlg.FileName);` — JohnG, Jan 15 '21 at 03:01
Thanks @JohnG. I have considered that, but I assumed there must be a better solution. I assume many people have ran into this same issue with the current dialogs provided in .NET. — Kyle Williamson, Jan 15 '21 at 13:46

score 1 · Accepted Answer · answered Jan 19 '21 at 10:27

I think that is not possible with the CommonOpenFileDialog
See: How to use IFileDialog with FOS_PICKFOLDER while still displaying file names in the dialog

The only way is to create your own custom dialog or you can use folder dialog with P/Invoke (based on SHBrowseForFolder like FolderBrowserDialog).
See: http://www.pinvoke.net/default.aspx/shell32.shbrowseforfolder

Copy the class from the link above and add the option BIF_BROWSEINCLUDEFILES.

public string SelectFolder(string caption, string initialPath, IntPtr parentHandle)
{
    _initialPath = initialPath;
    ...
    bi.ulFlags = BIF_NEWDIALOGSTYLE | BIF_SHAREABLE | BIF_BROWSEINCLUDEFILES;

Now files are displayed in the dialog unfortunately only like FolderBrowserDialog.

Michael Navara · Answer 2 · 2021-01-19T11:34:05.650

Is it possible to use something similar? Handle FolderChanging event and read the folder name?

private string SelectFolder()
{
    using (var dlg = new CommonOpenFileDialog()
    {
        Title = "Select folder to import from",
        AllowNonFileSystemItems = true,
        IsFolderPicker = true,
        EnsurePathExists = true,
        Multiselect = false,
        ShowPlacesList = true,
        InitialDirectory = "C:\\" //This must be handled manually
    })
    {
        dlg.FolderChanging += Dlg_FolderChanging;
        if (dlg.ShowDialog() == CommonFileDialogResult.Ok)
        {
            //Do things with the selected folder and the files within it...
            string selectedFolder = dlg.InitialDirectory;
            string dlgFileName = dlg.FileName;
            if (Directory.Exists(dlgFileName))
                selectedFolder = dlgFileName;
            else if (File.Exists(dlgFileName))
                selectedFolder = Path.GetDirectoryName(dlgFileName);
            else if (string.IsNullOrWhiteSpace(lastKnownFolder))
                selectedFolder = lastKnownFolder;

            return selectedFolder;
        }
    }

    return null;
}

private string lastKnownFolder = "";

private void Dlg_FolderChanging(object sender, CommonFileDialogFolderChangeEventArgs e)
{
    lastKnownFolder = e.Folder;
}

Using a CommonOpenFileDialog to select a folder but still show files within the folder in Windows 10

2 Answers2