In WPF, I want to use a Folder select dialog where the File is also displayed.

Question

I'm trying to implement a dialog where a folder can be selected when a button is clicked using WPF. So I searched the internet https://stackoverflow.com/questions/1922204/open-directory-dialog and tried several methods listed here.
The methods presented on that site are great solutions for implementing folder dialogs. However, I would like to know if there is a dialog where file is also displayed in the folder dialog in addition to this. In the various folder dialogs introduced on that site, only the folder is displayed, so it is difficult to know which files are in the folder.
Is there any other way? Thank you in advance.

Answer 1

You can use SHBrowseForFolder
with
BIF_BROWSEINCLUDEFILES

A test =>

           {  
                var hWnd = new System.Windows.Interop.WindowInteropHelper(this).Handle;  
                HRESULT hr = HRESULT.E_FAIL;  
                IntPtr pidlRet = IntPtr.Zero;  
                BROWSEINFO bi = new BROWSEINFO();  
                bi.hwndOwner = hWnd;  
                bi.lpszTitle = "Title";  
                bi.ulFlags = BIF_SHAREABLE | BIF_USENEWUI | BIF_BROWSEINCLUDEFILES;  
  
                IntPtr pidlRoot = IntPtr.Zero;  
                //Guid FOLDERID_PublicDocuments = new Guid("ED4824AF-DCE4-45A8-81E2-FC7965083634");  
                Guid FOLDERID_ComputerFolder = new Guid("0AC0837C-BBF8-452A-850D-79D08E667CA7");  
                hr = SHGetKnownFolderIDList(ref FOLDERID_ComputerFolder, 0, IntPtr.Zero, out pidlRoot);  
                bi.pidlRoot = pidlRoot;  
  
                pidlRet = SHBrowseForFolder(bi);  
                if (pidlRet != IntPtr.Zero)  
                {  
                    IntPtr pszSelectedPath = Marshal.AllocHGlobal(((260 + 1) * Marshal.SystemDefaultCharSize));  
                    bool bRetPath = SHGetPathFromIDList(pidlRet, pszSelectedPath);  
                    if (bRetPath)  
                    {  
                        string sSelectedPath = Marshal.PtrToStringUni(pszSelectedPath);  
                    }  
                    Marshal.FreeHGlobal(pszSelectedPath);  
                }  
            }  

Declarations :

        public enum HRESULT : int  
        {  
            S_OK = 0,  
            S_FALSE = 1,  
            E_NOINTERFACE = unchecked((int)0x80004002),  
            E_NOTIMPL = unchecked((int)0x80004001),  
            E_FAIL = unchecked((int)0x80004005),  
        }  
  
        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]  
        public class BROWSEINFO  
        {  
            public IntPtr hwndOwner;  
            public IntPtr pidlRoot;  
            public IntPtr pszDisplayName;  
            public string lpszTitle;  
            public int ulFlags;  
            public BrowseCallbackProc lpfn;  
            public IntPtr lParam;  
            public int iImage;  
        }  
  
        public delegate int BrowseCallbackProc(IntPtr hwnd, int msg, IntPtr lParam, IntPtr lpData);  
  
        [DllImport("Shell32.dll", SetLastError = true, CharSet = CharSet.Unicode)]  
        public static extern IntPtr SHBrowseForFolder([In] BROWSEINFO lpbi);  
  
        // Browsing for directory.  
        public const int BIF_RETURNONLYFSDIRS = 0x00000001;  // For finding a folder to start document searching  
        public const int BIF_DONTGOBELOWDOMAIN = 0x00000002;  // For starting the Find Computer  
        public const int BIF_STATUSTEXT = 0x00000004;   // 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.  
        public const int BIF_RETURNFSANCESTORS = 0x00000008;  
        public const int BIF_EDITBOX = 0x00000010;   // Add an editbox to the dialog  
        public const int BIF_VALIDATE = 0x00000020;   // insist on valid result (or CANCEL)  
  
        public const int BIF_NEWDIALOGSTYLE = 0x00000040;   // Use the new dialog layout with the ability to resize  
                                                            // Caller needs to call OleInitialize() before using this API  
  
        public const int BIF_USENEWUI = (BIF_NEWDIALOGSTYLE | BIF_EDITBOX);  
  
        public const int BIF_BROWSEINCLUDEURLS = 0x00000080;   // Allow URLs to be displayed or entered. (Requires BIF_USENEWUI)  
        public const int BIF_UAHINT = 0x00000100;   // Add a UA hint to the dialog, in place of the edit box. May not be combined with BIF_EDITBOX  
        public const int BIF_NONEWFOLDERBUTTON = 0x00000200;   // Do not add the "New Folder" button to the dialog.  Only applicable with BIF_NEWDIALOGSTYLE.  
        public const int BIF_NOTRANSLATETARGETS = 0x00000400;   // don't traverse target as shortcut  
  
        public const int BIF_BROWSEFORCOMPUTER = 0x00001000;  // Browsing for Computers.  
        public const int BIF_BROWSEFORPRINTER = 0x00002000;  // Browsing for Printers  
        public const int BIF_BROWSEINCLUDEFILES = 0x00004000;  // Browsing for Everything  
        public const int BIF_SHAREABLE = 0x00008000;  // sharable resources displayed (remote shares, requires BIF_USENEWUI)  
        public const int BIF_BROWSEFILEJUNCTIONS = 0x00010000;  // allow folder junctions like zip files and libraries to be browsed  
  
        [DllImport("Shell32.dll", SetLastError = true, CharSet = CharSet.Unicode)]  
        public static extern bool SHGetPathFromIDList(IntPtr pidl, IntPtr pszPath);  
  
        [DllImport("Shell32.dll", SetLastError = true, CharSet = CharSet.Unicode)]  
        public static extern HRESULT SHILCreateFromPath([MarshalAs(UnmanagedType.LPWStr)] string pszPath, ref IntPtr ppIdl, ref uint rgflnOut);  
  
        [DllImport("Shell32.dll", SetLastError = true, CharSet = CharSet.Unicode)]  
        public static extern HRESULT SHGetKnownFolderIDList(ref Guid rfid, uint dwFlags, IntPtr hToken, out IntPtr ppidl);  
  
        public enum KNOWN_FOLDER_FLAG  
        {  
            KF_FLAG_DEFAULT,  
            KF_FLAG_FORCE_APP_DATA_REDIRECTION,  
            KF_FLAG_RETURN_FILTER_REDIRECTION_TARGET,  
            KF_FLAG_FORCE_PACKAGE_REDIRECTION,  
            KF_FLAG_NO_PACKAGE_REDIRECTION,  
            KF_FLAG_FORCE_APPCONTAINER_REDIRECTION,  
            KF_FLAG_NO_APPCONTAINER_REDIRECTION,  
            KF_FLAG_CREATE,  
            KF_FLAG_DONT_VERIFY,  
            KF_FLAG_DONT_UNEXPAND,  
            KF_FLAG_NO_ALIAS,  
            KF_FLAG_INIT,  
            KF_FLAG_DEFAULT_PATH,  
            KF_FLAG_NOT_PARENT_RELATIVE,  
            KF_FLAG_SIMPLE_IDLIST,  
            KF_FLAG_ALIAS_ONLY  
        }