Mark Salsbery - Professional Profile

Do you need to present a folder browser dialog to the user from your WPF app?

Sure, you can use the FolderBrowserDialog Class[^], but what self-respecting WPF
programmer wants to pull in the System.Windows.Forms namespace
and its associated DLL(s)?

Not me. Smile | :)

Here's a simple wrapper around the SHBrowseForFolder Function[^] that I posted
on the WPF board.

I'm not sure it's article-worthy, so for now I'll just keep it here in case
someone asks for it.

On to the code, in its entirety, with an example of its usage following...

// .NET 3.5, Visual Studio 2008 SP1, Windows XP or better...

using System;
using System.Text;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Interop;


namespace CommonDialogWrappers
{
    /// <summary>
    /// Represents a common dialog box (Win32::SHBrowseForFolder()) that allows a user to select a folder.
    /// </summary>
    public class BrowseForFolderDialog
    {
        #region Public Properties

        /// <summary>
        /// Gets the current and or final selected folder path.
        /// </summary>
        public string SelectedFolder { get; protected set; }
        /// <summary>
        /// Gets or sets the string that is displayed above the tree view control in the dialog box (must set BEFORE calling ShowDialog()). 
        /// </summary>
        public string Title
        {
            get { return BrowseInfo.lpszTitle; }
            set { BrowseInfo.lpszTitle = value; }
        }
        /// <summary>
        /// Gets or sets the initially selected folder path.
        /// </summary>
        public string InitialFolder { get; set; }
        /// <summary>
        /// Gets or sets the initially selected and expanded folder path.  Overrides SelectedFolder.
        /// </summary>
        public string InitialExpandedFolder { get; set; }
        /// <summary>
        /// Gets or sets the text for the dialog's OK button.
        /// </summary>
        public string OKButtonText { get; set; }
        BROWSEINFOW browseInfo;
        /// <summary>
        /// Provides direct access to the Win32::SHBrowseForFolder() BROWSEINFO structure used to create the dialog in ShowDialog().
        /// </summary>
        public BROWSEINFOW BrowseInfo
        {
            get { return browseInfo; }
            protected set { browseInfo = value; }
        }
        /// <summary>
        /// Provides direct access to the ulFlags field of the Win32::SHBrowseForFolder() structure used to create the dialog in ShowDialog().
        /// </summary>
        public BrowseInfoFlags BrowserDialogFlags
        {
            get { return BrowseInfo.ulFlags; }
            set { BrowseInfo.ulFlags = value; }
        }

        #endregion


        #region Public Constructors

        /// <summary>
        /// Constructs a BrowseForFolderDialog with default BrowseInfoFlags set to BIF_NEWDIALOGSTYLE.
        /// </summary>
        public BrowseForFolderDialog()
        {
            BrowseInfo = new BROWSEINFOW();
            BrowseInfo.hwndOwner = IntPtr.Zero;
            BrowseInfo.pidlRoot = IntPtr.Zero;
            BrowseInfo.pszDisplayName = new String(' ', 260);
            BrowseInfo.lpszTitle = "Select a folder:";
            BrowseInfo.ulFlags = BrowseInfoFlags.BIF_NEWDIALOGSTYLE;
            BrowseInfo.lpfn = new BrowseCallbackProc(BrowseEventHandler);
            BrowseInfo.lParam = IntPtr.Zero;
            BrowseInfo.iImage = -1;
        }

        #endregion


        #region Public ShowDialog() Overloads

        /// <summary>
        /// Shows the dialog (Win32::SHBrowseForFolder()).
        /// </summary>
        public Nullable<bool> ShowDialog()
        {
            return PInvokeSHBrowseForFolder(null);
        }

        /// <summary>
        /// Shows the dialog (Win32::SHBrowseForFolder()) with its hwndOwner set to the handle of 'owner'.
        /// </summary>
        public Nullable<bool> ShowDialog(Window owner)
        {
            return PInvokeSHBrowseForFolder(owner);
        }

        #endregion


        #region PInvoke Stuff

        private Nullable<bool> PInvokeSHBrowseForFolder(Window owner)
        {
            WindowInteropHelper windowhelper;
            if (null != owner)
            {
                windowhelper = new WindowInteropHelper(owner);
                BrowseInfo.hwndOwner = windowhelper.Handle;
            }

            IntPtr pidl = SHBrowseForFolderW(browseInfo);

            if (IntPtr.Zero != pidl)
            {
                StringBuilder pathsb = new StringBuilder(260);
                if (false != SHGetPathFromIDList(pidl, pathsb))
                {
                    SelectedFolder = pathsb.ToString();
                    Marshal.FreeCoTaskMem(pidl);
                    return true;
                }
            }

            return false;
        }

        private int BrowseEventHandler(IntPtr hwnd, MessageFromBrowser uMsg, IntPtr lParam, IntPtr lpData)
        {
            switch (uMsg)
            {
                case MessageFromBrowser.BFFM_INITIALIZED:
                {
                    // The dialog box has finished initializing.
                    // lParam   Not used, value is NULL.

                    if (!string.IsNullOrEmpty(InitialExpandedFolder))
                        SendMessageW(hwnd, MessageToBrowser.BFFM_SETEXPANDED, new IntPtr(1), InitialExpandedFolder);
                    else if (!string.IsNullOrEmpty(InitialFolder))
                        SendMessageW(hwnd, MessageToBrowser.BFFM_SETSELECTIONW, new IntPtr(1), InitialFolder);

                    if (!string.IsNullOrEmpty(OKButtonText))
                        SendMessageW(hwnd, MessageToBrowser.BFFM_SETOKTEXT, new IntPtr(1), OKButtonText);

                    break;
                }
                case MessageFromBrowser.BFFM_SELCHANGED:
                {
                    // The selection has changed in the dialog box.
                    // lParam   A pointer to an item identifier list (PIDL) identifying the newly selected item.

                    StringBuilder pathsb = new StringBuilder(260);
                    if (false != SHGetPathFromIDList(lParam, pathsb))
                    {
                        SelectedFolder = pathsb.ToString();
                    }

                    break;
                }
                case MessageFromBrowser.BFFM_VALIDATEFAILEDA:   // ANSI
                {
                    // The user typed an invalid name into the dialog's edit box. A nonexistent folder is considered an invalid name.
                    // lParam   A pointer to a string containing the invalid name. An application can use this data in an error dialog informing the user that the name was not valid.
                    // Return zero to dismiss the dialog or nonzero to keep the dialog displayed
                    break;
                }
                case MessageFromBrowser.BFFM_VALIDATEFAILEDW:   // Unicode
                {
                    // The user typed an invalid name into the dialog's edit box. A nonexistent folder is considered an invalid name.
                    // lParam   A pointer to a string containing the invalid name. An application can use this data in an error dialog informing the user that the name was not valid.
                    // Return zero to dismiss the dialog or nonzero to keep the dialog displayed
                    break;
                }
                case MessageFromBrowser.BFFM_IUNKNOWN:
                {
                    // An IUnknown interface is available to the dialog box.
                    // lParam   A pointer to an IUnknown interface.
                    break;
                }
            }

            return 0;
        }

        public delegate int BrowseCallbackProc(IntPtr hwnd, MessageFromBrowser uMsg, IntPtr lParam, IntPtr lpData);

        [Flags]
        public enum BrowseInfoFlags : uint
        {
            /// <summary>
            /// No specified BIF_xxx flags.
            /// </summary>
            BIF_None = 0x0000,
            /// <summary>
            /// Only return file system directories. If the user selects folders that are not part of the file system, the OK button is grayed.
            /// </summary>
            BIF_RETURNONLYFSDIRS = 0x0001,  // For finding a folder to start document searching
            /// <summary>
            /// Do not include network folders below the domain level in the dialog box's tree view control.
            /// </summary>
            BIF_DONTGOBELOWDOMAIN = 0x0002, // For starting the Find Computer
            /// <summary>
            /// Include a status area in the dialog box. 
            /// </summary>
            BIF_STATUSTEXT = 0x0004,        // Top of the dialog has 2 lines of text for BROWSEINFO.lpszTitle and one line if
                                            // this flag is set.  Passing the message BFFM_SETSTATUSTEXTA to the hwnd can set the
                                            // rest of the text.  This is not used with BIF_USENEWUI and BROWSEINFO.lpszTitle gets
                                            // all three lines of text.
            /// <summary>
            /// Only return file system ancestors. An ancestor is a subfolder that is beneath the root folder in the namespace hierarchy.
            /// </summary>
            BIF_RETURNFSANCESTORS = 0x0008,
            /// <summary>
            /// Include an edit control in the browse dialog box that allows the user to type the name of an item.
            /// </summary>
            BIF_EDITBOX = 0x0010,           // Add an editbox to the dialog
            /// <summary>
            /// If the user types an invalid name into the edit box, the browse dialog box will call the application's BrowseCallbackProc with the BFFM_VALIDATEFAILED message. 
            /// </summary>
            BIF_VALIDATE = 0x0020,          // insist on valid result (or CANCEL)
            /// <summary>
            /// Use the new user interface. Setting this flag provides the user with a larger dialog box that can be resized.
            /// </summary>
            BIF_NEWDIALOGSTYLE = 0x0040,    // Use the new dialog layout with the ability to resize
                                            // Caller needs to call OleInitialize() before using this API
            /// <summary>
            /// Use the new user interface, including an edit box. This flag is equivalent to BIF_EDITBOX | BIF_NEWDIALOGSTYLE. 
            /// </summary>
            BIF_USENEWUI = BIF_NEWDIALOGSTYLE | BIF_EDITBOX,
            /// <summary>
            /// The browse dialog box can display URLs. The BIF_USENEWUI and BIF_BROWSEINCLUDEFILES flags must also be set. 
            /// </summary>
            BIF_BROWSEINCLUDEURLS = 0x0080, // Allow URLs to be displayed or entered. (Requires BIF_USENEWUI)
            /// <summary>
            /// When combined with BIF_NEWDIALOGSTYLE, adds a usage hint to the dialog box in place of the edit box.
            /// </summary>
            BIF_UAHINT = 0x0100,            // Add a UA hint to the dialog, in place of the edit box. May not be combined with BIF_EDITBOX
            /// <summary>
            /// Do not include the New Folder button in the browse dialog box.
            /// </summary>
            BIF_NONEWFOLDERBUTTON = 0x0200, // Do not add the "New Folder" button to the dialog.  Only applicable with BIF_NEWDIALOGSTYLE.
            /// <summary>
            /// When the selected item is a shortcut, return the PIDL of the shortcut itself rather than its target.
            /// </summary>
            BIF_NOTRANSLATETARGETS = 0x0400,// don't traverse target as shortcut
            /// <summary>
            /// Only return computers. If the user selects anything other than a computer, the OK button is grayed.
            /// </summary>
            BIF_BROWSEFORCOMPUTER = 0x1000, // Browsing for Computers.
            /// <summary>
            /// Only allow the selection of printers. If the user selects anything other than a printer, the OK button is grayed. 
            /// </summary>
            BIF_BROWSEFORPRINTER = 0x2000,  // Browsing for Printers
            /// <summary>
            /// The browse dialog box will display files as well as folders.
            /// </summary>
            BIF_BROWSEINCLUDEFILES = 0x4000,// Browsing for Everything
            /// <summary>
            /// The browse dialog box can display shareable resources on remote systems. 
            /// </summary>
            BIF_SHAREABLE = 0x8000          // sharable resources displayed (remote shares, requires BIF_USENEWUI)
        }

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
        public class BROWSEINFOW
        {
            /// <summary>
            /// A handle to the owner window for the dialog box.
            /// </summary>
            public IntPtr hwndOwner;
            /// <summary>
            /// A pointer to an item identifier list (PIDL) specifying the location of the root folder from which to start browsing. 
            /// </summary>
            public IntPtr pidlRoot;         // PCIDLIST_ABSOLUTE
            /// <summary>
            /// The address of a buffer to receive the display name of the folder selected by the user. The size of this buffer is assumed to be MAX_PATH characters.
            /// </summary>
            public string pszDisplayName;   // Output parameter! (length must be >= MAX_PATH)
            /// <summary>
            /// The address of a null-terminated string that is displayed above the tree view control in the dialog box. 
            /// </summary>
            public string lpszTitle;
            /// <summary>
            /// Flags specifying the options for the dialog box. 
            /// </summary>
            public BrowseInfoFlags ulFlags;
            /// <summary>
            /// A BrowseCallbackProc delegate that the dialog box calls when an event occurs.
            /// </summary>
            public BrowseCallbackProc lpfn;
            /// <summary>
            /// An application-defined value that the dialog box passes to the BrowseCallbackProc delegate, if one is specified.
            /// </summary>
            public IntPtr lParam;
            /// <summary>
            /// A variable to receive the image associated with the selected folder. The image is specified as an index to the system image list.
            /// </summary>
            public int iImage;              // Output parameter!
        }

        // message from browser
        public enum MessageFromBrowser : uint
        {
            /// <summary>
            /// The dialog box has finished initializing.
            /// </summary>
            BFFM_INITIALIZED = 1,
            /// <summary>
            /// The selection has changed in the dialog box.
            /// </summary>
            BFFM_SELCHANGED = 2,
            /// <summary>
            /// (ANSI) The user typed an invalid name into the dialog's edit box. A nonexistent folder is considered an invalid name.
            /// </summary>
            BFFM_VALIDATEFAILEDA = 3,
            /// <summary>
            /// (Unicode) The user typed an invalid name into the dialog's edit box. A nonexistent folder is considered an invalid name.
            /// </summary>
            BFFM_VALIDATEFAILEDW = 4,
            /// <summary>
            /// An IUnknown interface is available to the dialog box.
            /// </summary>
            BFFM_IUNKNOWN = 5
        }

        // messages to browser
        public enum MessageToBrowser : uint
        {

            /// <summary>
            /// Win32 API macro - start of user defined window message range.
            /// </summary>
            WM_USER = 0x0400,
            /// <summary>
            /// (ANSI) Sets the status text. Set lpData to point to a null-terminated string with the desired text. 
            /// </summary>
            BFFM_SETSTATUSTEXTA = WM_USER + 100,
            /// <summary>
            /// Enables or disables the dialog box's OK button.  lParam - To enable, set to a nonzero value. To disable, set to zero.
            /// </summary>
            BFFM_ENABLEOK = WM_USER + 101,
            /// <summary>
            /// (ANSI) Specifies the path of a folder to select. 
            /// </summary>
            BFFM_SETSELECTIONA = WM_USER + 102,
            /// <summary>
            /// (Unicode) Specifies the path of a folder to select. 
            /// </summary>
            BFFM_SETSELECTIONW = WM_USER + 103,
            /// <summary>
            /// (Unicode) Sets the status text. Set lpData to point to a null-terminated string with the desired text. 
            /// </summary>
            BFFM_SETSTATUSTEXTW = WM_USER + 104,
            /// <summary>
            /// Sets the text that is displayed on the dialog box's OK button.
            /// </summary>
            BFFM_SETOKTEXT = WM_USER + 105,       // Unicode only
            /// <summary>
            /// Specifies the path of a folder to expand in the Browse dialog box. 
            /// </summary>
            BFFM_SETEXPANDED = WM_USER + 106      // Unicode only
        }

        [DllImport("shell32.dll")]
        private static extern IntPtr SHBrowseForFolderW([MarshalAs(UnmanagedType.LPStruct), In, Out] BROWSEINFOW bi);
        [DllImport("shell32.dll")]
        private static extern bool SHGetPathFromIDList(IntPtr pidl, StringBuilder path);
        [DllImport("user32.dll")]
        public static extern IntPtr SendMessageW(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);
        [DllImport("user32.dll")]
        public static extern IntPtr SendMessageW(IntPtr hWnd, MessageToBrowser msg, IntPtr wParam, [MarshalAs(UnmanagedType.LPWStr)] string str);

        #endregion
    }
}

Example:

CommonDialogWrappers.BrowseForFolderDialog dlg = new CommonDialogWrappers.BrowseForFolderDialog();
dlg.Title = "Select a folder and click OK!";
dlg.InitialExpandedFolder = @"c:\";
dlg.OKButtonText = "OK!";
if (true == dlg.ShowDialog(this))
{
    // Do something with the selected folder...
    MessageBox.Show(dlg.SelectedFolder, "Selected Folder");
}

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Hello sir,
After searching for a no of sites for this control,I came to this post.
In my opinion U should write an article on this control Because I haven't seen any File Browser Control in WPF till now(if it exists now,plz do let me know ).
Anyways,Coming to point ,Can i use it ?
I am making an open source next generation Media Player(Hope to make it better than existing ones) and i am looking for such control.
If yes for permission to use it,What are the terms?
Will your name and blog reference in the class will make the way.
Great job,
sonam
(sonamsingh_19@yahoo.co.in)

I walk in rain ....so that no one can see me crying. Smile | :)

Hi sonam,

I appreciate you asking! Feel free to use it - all the code is right there.

I could make an article, but I'm not sure what else to say about it. Smile | :)

It's just a managed wrapper around the Win32 SHBrowseForFolder() API, and most of
the summary text came right from the Platform SDK header files.

Docs: SHBrowseForFolder Function[^]

Enjoy!

Cheers,
Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

There is a set of file and folder browser controls (commercial though) for WPF : Shell MegaPack.WPF

Thanks for posting this Mark.
Maybe you should post this as a short and sweet article. I knew that "someone" had posted this but danged if I could remember who or where.

Why is common sense not common?
Never argue with an idiot. They will drag you down to their level where they are an expert.
Sometimes it takes a lot of work to be lazy
Individuality is fine, as long as we do it together - F. Burns

Help humanity, join the CodeProject grid computing team here

This is great. The only bug I see that is that there are folders with "." or period characters in them and they don't display the period or anything after.

For example, these show blank
.dia
.eclipse
.idlerc

These only show the first part
Paint.NET (shows Paint instead of Paint.NET)
org.eclipse.platform_3.5.0_920333535 only shows (org.eclipse.platform_3.5)

rhyous wrote:
This is great. The only bug I see that is that there are folders with "." or period characters in them and they don't display the period or anything after.

I'm unable to reproduce that on Windows 7.

Is it something you see in my wrapper code?

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

I am on Windows 7 64 bit using Visual Studio 2008.

Don't worry, I have what I need using Ookii Dialogs.

Thanks,

Jared

This works really well. Thanks. I looked at a lot of other solutions and nothing was half as good as this. Rose | [Rose]

Cool

Glad it was useful!

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Cheers Fella Smile | :)

I've just started playing around in .NET and couldn't believe that I was going to have to code my own CommonDialog for folder selection Smile | :)

Thanks,
I wish you had made a TIP or a small article with this code in there.
This is a great approach if you can live with a non styled Common Dialog box.

Check...Check One...Check...Is this thing on?

I got caught fishing[^] with a McDonalds employee Cry | :((

I think I should have seen this one coming and not responded to the original post. D'Oh! | :doh:

I saw that!

Good luck man Smile | :)

Mark

Mark, we have a Problem[^] D'Oh! | :doh:

Many are stubborn in pursuit of the path they have chosen, few in pursuit of the goal - Friedrich Nietzsche

.·´¯`·->Rajesh<-·´¯`·.
[Microsoft MVP - Visual C++]

Good one!

Thanks for sharing Smile | :)

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

I just read the thread - my head is still spinning trying to comprehend where he was coming from, without leaping to the conclusion that he was an idiot.

¡El diablo está en mis pantalones! ¡Mire, mire!

Real Mentats use only 100% pure, unfooled around with Sapho Juice(tm)!

SELECT * FROM User WHERE Clue > 0
0 rows returned

Save an Orange - Use the VCF!
VCF Blog

That's why I wished led mike good luck!

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Jim, how the heck did you come to this thread? Just curious. Smile | :)

If memory serves, I think I came across a reply Mark made to my post from a few days ago. I thought it was amusing and checked out an article of his, then came across his profile, and then this thread Smile | :)

I think.

¡El diablo está en mis pantalones! ¡Mire, mire!

Real Mentats use only 100% pure, unfooled around with Sapho Juice(tm)!

SELECT * FROM User WHERE Clue > 0
0 rows returned

Save an Orange - Use the VCF!
VCF Blog

led mike wrote:
Jim, how the heck did you come to this thread? Just curious.

Now you may wonder how I'm here too. $Shucks | :-\$

Nobody can give you wiser advice than yourself. - Cicero
.·´¯`·->Rajesh<-·´¯`·.
Codeproject.com: Visual C++ MVP

Look at this[^] Frown | :(

I recognize this guy. He has been on here for months now and does not seem to be making progress. I think he needs a career change.

2 or 3 days of this[^] has me wondering if this person is real (sadly) or just a joker.

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

He is either a troll or suffering severe bouts of the ID Ten T condition.

Mark Salsbery - Professional Profile

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