How do I open a FolderBrowserDialog at the selected folder?

Question

I have a FolderBrowserDialog, displayed with code shown below. However, it keeps opening with 'Computer', i.e. the root of the folder tree, selected. How do I get it to open on the selected folder?

       var folderBrowser = new FolderBrowserDialog();
        folderBrowser.Description = "Select Chase 6 Installation Folder";
        folderBrowser.RootFolder = Environment.SpecialFolder.MyComputer;
        folderBrowser.ShowNewFolderButton = false;
        if (Directory.Exists(Properties.Settings.Default.defaultChasePath))
        {
            string x = Properties.Settings.Default.defaultChasePath;
            folderBrowser.SelectedPath = x;
        }
        if (folderBrowser.ShowDialog(this) == DialogResult.OK)
        {
            chasePathtext.Text = folderBrowser.SelectedPath;
        }

Answer 1

From the Microsoft help for FolderBrowserDialog class:

Typically, after creating a new FolderBrowserDialog, you set the RootFolder to the location from which to start browsing. Optionally, you can set the SelectedPath to an absolute path of a subfolder of RootFolder that will initially be selected.

Are you possibly setting the SelectedPath to a location that doesn't equate to a subfolder of RootFolder (i.e. My Computer)? That would probably cause it to dive back to the RootFolder as the presented location.

Answer 2

The folderbrowser dialog is a wrapper around a windows API call that does not match all the relevant paths possible ( I suppose that would be an uphill task..) this can be mimicked using your own class though. Generate the following class inside your application (adding namespace and System.Reflection)

public class RootSetter
{
    [Flags()]
    public enum CsIdl
    {
        Desktop = 0x0000, // Desktop
        Internet = 0x0001, // Internet Explorer (icon on desktop)
        Programs = 0x0002, // Start Menu\Programs
        Controls = 0x0003, // My Computer\Control Panel
        Printers = 0x0004, // My Computer\Printers
        Personal = 0x0005, // My Documents
        Favorites = 0x0006, // user name\Favorites
        Startup = 0x0007, // Start Menu\Programs\Startup
        Recent = 0x0008, // user name\Recent
        SendTo = 0x0009, // user name\SendTo
        BitBucket = 0x000a, // desktop\Recycle Bin
        StartMenu = 0x000b, // user name\Start Menu
        MyDocuments = 0x000c, // logical "My Documents" desktop icon
        MyMusic = 0x000d, // "My Music" folder
        MyVideo = 0x000e, // "My Videos" folder
        DesktopDirectory = 0x0010, // user name\Desktop
        Drives = 0x0011, // My Computer
        Network = 0x0012, // Network Neighborhood (My Network Places)
        Nethood = 0x0013, // user name\nethood
        Fonts = 0x0014, // windows\fonts
        Templates = 0x0015,
        CommonStartMenu = 0x0016, // All Users\Start Menu
        CommonPrograms = 0x0017, // All Users\Start Menu\Programs
        CommonStartup = 0x0018, // All Users\Startup
        CommonDesktopDirectory = 0x0019, // All Users\Desktop
        AppData = 0x001a, // user name\Application Data
        PrintHood = 0x001b, // user name\PrintHood
        LocalAppData = 0x001c, // user name\Local Settings\Applicaiton Data (non roaming)
        AltStartup = 0x001d, // non localized startup
        CommonAltStartup = 0x001e, // non localized common startup
        CommonFavorites = 0x001f,
        InternetCache = 0x0020,
        Cookies = 0x0021,
        History = 0x0022,
        CommonAppdata = 0x0023, // All Users\Application Data
        Windows = 0x0024, // GetWindowsDirectory()
        System = 0x0025, // GetSystemDirectory()
        ProgramFiles = 0x0026, // C:\Program Files
        MyPictures = 0x0027, // C:\Program Files\My Pictures
        Profile = 0x0028, // USERPROFILE
        SystemX86 = 0x0029, // x86 system directory on RISC
        ProgramFilesX86 = 0x002a, // x86 C:\Program Files on RISC
        ProgramFilesCommon = 0x002b, // C:\Program Files\Common
        ProgramFilesCommonx86 = 0x002c, // x86 Program Files\Common on RISC
        CommonTemplates = 0x002d, // All Users\Templates
        CommonDocuments = 0x002e, // All Users\Documents
        CommonAdminTools = 0x002f, // All Users\Start Menu\Programs\Administrative Tools
        AdminTools = 0x0030, // user name\Start Menu\Programs\Administrative Tools
        Connections = 0x0031, // Network and Dial-up Connections
        CommonMusic = 0x0035, // All Users\My Music
        CommonPictures = 0x0036, // All Users\My Pictures
        CommonVideo = 0x0037, // All Users\My Video
        Resources = 0x0038, // Resource Direcotry
        ResourcesLocalized = 0x0039, // Localized Resource Direcotry
        CommonOemLinks = 0x003a, // Links to All Users OEM specific apps
        CdBurnArea = 0x003b, // USERPROFILE\Local Settings\Application Data\Microsoft\CD Burning
        ComputersNearMe = 0x003d, // Computers Near Me (computered from Workgroup membership)
        FlagCreate = 0x8000, // combine with CSIDL_ value to force folder creation in SHGetFolderPath()
        FlagDontVerify = 0x4000, // combine with CSIDL_ value to return an unverified folder path
        FlagNoAlias = 0x1000, // combine with CSIDL_ value to insure non-alias versions of the pidl
        FlagPerUserInit = 0x0800, // combine with CSIDL_ value to indicate per-user init (eg. upgrade)
        FlagMask = 0xFF00, // mask for all possible flag values
    }

    public static void SetRootFolder(System.Windows.Forms.FolderBrowserDialog fbd, CsIdl csidl)
    {
        Type t = fbd.GetType();
        FieldInfo fi = t.GetField("rootFolder", BindingFlags.Instance | BindingFlags.NonPublic);
        fi.SetValue(fbd, (System.Environment.SpecialFolder)csidl);
    }

and then inside your calling class when setting the root folder use the following syntax. It would be better to check the enum fior a close value should you find one but if you cannto then the one below is fairly generic and allows me to move thorugh my C drive easily enough.

private void button1_Click(object sender, EventArgs e)
    {
        FolderBrowserDialog folderBrowser = new FolderBrowserDialog(); 
        folderBrowser.Description = "Select Chase 6 Installation Folder"; 
        folderBrowser.RootFolder = Environment.SpecialFolder.ProgramFiles; 
        folderBrowser.ShowNewFolderButton = false; 

        if (Directory.Exists(Properties.Settings.Default.defaultChasePath)) 
        { 
            string x = Properties.Settings.Default.defaultChasePath; 

            //Use API Flag to set correct path, following tahter a catch all better to check
            //enum for full list
            RootSetter.SetRootFolder(folderBrowser, RootSetter.CsIdl.FlagDontVerify);

            folderBrowser.SelectedPath = x;

        } 
        if (folderBrowser.ShowDialog(this) == DialogResult.OK) 
        { 
            string huz = folderBrowser.SelectedPath; 
        }
    }

Hope that helps :)

Answer 3

I was trying to assign a non-existent folder path to the SelectedFolder property. When you use a valid path, the root folder loses relevance. When you don't assign a SelectedFolder value, at least one of the Environment.SepcialFolder values will suffice.

COMING SOON: Attempts at using reflection to dynamically set a non-special root folder. Stay tuned.

Answer 4

If you set RootFolder to Environment.SpecialFolder.Desktop then it will open to the SelectedFolder as long as the path is valid.

When you set RootFolder to Environment.SpecialFolder.MyComputer, then the first time the dialog opens, it will always start at MyComputer, not the SelectedFolder path.

If a valid selection is made, then subsequent uses of the same FolderBrowserDialog instance will open at the previously selected path.

Answer 5

To select existing path (no special f...ng folders) you must write own treeview based form.