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

Answer 1

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 :)