シェルネームスペースを利用して デスクトップ フォルダのサブフォルダ (子フォルダ)の一覧を取得するコードを紹介します。
子フォルダを取得するには、親フォルダのIShellFolderを取得し、IShellFolderのEnumObjects()メソッドを呼び出します。フォルダの一覧はIEnumIDLlistで取得できます。個々の要素のPIDLはIEnumIDLlist.Next()メソッドで取得します。
取得したPIDLをSHGetFileInfo()に与え、ファイル・フォルダの情報を取得します。
取得した要素がフォルダである場合、さらにその子フォルダを調べるために、そのフォルダのIShellFolderをBindToObject() APIで取得します。
以下で紹介しているプログラムは、EnumObjectsを取得した後、１項目ずつ要素を取得しています。この方法では
ファイル数が増えるとパフォーマンスが低下するため、バッファサイズを指定して、一度にまとめて読み込む方法に修正しています。
下図のフォームを作成します。
Miultilinesプロパティをtrueに設定したテキストボックスとボタンを配置します。
以下のコードを記述します。
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace ShellObjectsDemo2025
{
public partial class FormDesktopShellFolder : Form
{
public class ShellInfo
{
public IntPtr pIDL;
public IntPtr pIDL_Relative;
public bool IsFolder;
public bool HasSubFolder;
public bool IsDropTarget;
public bool IsStream;
public bool IsFileSystem;
public bool IsLink;
public bool IsNonEnumerated;
public bool IsSystem;
public string DisplayName = "";
public string TypeName = "";
public string Path = "";
public int IconIndex;
}
public FormDesktopShellFolder()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
WindowsAPI.IShellFolder DesktopShellFolder;
IntPtr Desktop_pIDL = IntPtr.Zero;
WindowsAPI.SHGetDesktopFolder(out DesktopShellFolder);
WindowsAPI.SHGetSpecialFolderLocation(IntPtr.Zero, WindowsAPI.CSIDL.CSIDL_DESKTOP, ref Desktop_pIDL);
List<ShellInfo> childinf = GetSubItems(DesktopShellFolder, Desktop_pIDL);
foreach (ShellInfo ci in childinf) {
textBox1.Text += ci.DisplayName + "\r\n";
}
}
public void GetShellInfoFromPIDL(WindowsAPI.IShellFolder ParentShellFolder, IntPtr Parent_pIDL, IntPtr pIDL, out ShellInfo sinf)
{
sinf = new ShellInfo();
if (ParentShellFolder != null) {
// We need the Desktop shell item to exist first.
// Create the FQ PIDL for this new item.
sinf.pIDL = WindowsAPI.ILCombine(Parent_pIDL, pIDL);
sinf.pIDL_Relative = WindowsAPI.ILClone(pIDL);
// Now we want to get extended attributes such as the icon index etc.
WindowsAPI.SHFILEINFO shInfo = new WindowsAPI.SHFILEINFO();
WindowsAPI.SHGFI vFlags = WindowsAPI.SHGFI.SHGFI_SMALLICON | WindowsAPI.SHGFI.SHGFI_SYSICONINDEX | WindowsAPI.SHGFI.SHGFI_PIDL | WindowsAPI.SHGFI.SHGFI_DISPLAYNAME | WindowsAPI.SHGFI.SHGFI_TYPENAME;
WindowsAPI.SHGetFileInfo(pIDL, 0, out shInfo, (uint)Marshal.SizeOf(shInfo), vFlags);
sinf.DisplayName = shInfo.szDisplayName;
sinf.TypeName = shInfo.szTypeName;
sinf.IconIndex = shInfo.iIcon;
sinf.Path = GetPath(sinf.pIDL);
WindowsAPI.SFGAOF uFlags = WindowsAPI.SFGAOF.SFGAO_FOLDER | WindowsAPI.SFGAOF.SFGAO_HASSUBFOLDER
| WindowsAPI.SFGAOF.SFGAO_STREAM | WindowsAPI.SFGAOF.SFGAO_DROPTARGET | WindowsAPI.SFGAOF.SFGAO_FILESYSTEM | WindowsAPI.SFGAOF.SFGAO_LINK | WindowsAPI.SFGAOF.SFGAO_SYSTEM;
ParentShellFolder.GetAttributesOf(1, new IntPtr[] { pIDL }, ref uFlags);
//shDesktop.GetAttributesOf(1, new IntPtr[]{ m_pIDL}, ref uFlags);
sinf.IsFolder = Convert.ToBoolean(uFlags & WindowsAPI.SFGAOF.SFGAO_FOLDER);
sinf.HasSubFolder = Convert.ToBoolean(uFlags & WindowsAPI.SFGAOF.SFGAO_HASSUBFOLDER);
sinf.IsDropTarget = Convert.ToBoolean(uFlags & WindowsAPI.SFGAOF.SFGAO_DROPTARGET);
sinf.IsStream = Convert.ToBoolean(uFlags & WindowsAPI.SFGAOF.SFGAO_STREAM);
sinf.IsFileSystem = Convert.ToBoolean(uFlags & WindowsAPI.SFGAOF.SFGAO_FILESYSTEM);
sinf.IsLink = Convert.ToBoolean(uFlags & WindowsAPI.SFGAOF.SFGAO_LINK);
sinf.IsSystem = Convert.ToBoolean(uFlags & WindowsAPI.SFGAOF.SFGAO_SYSTEM);
}
}
/// <summary>
/// Retrieves an array of ShellItem objects for sub-folders of this shell item.
/// </summary>
/// <returns>ArrayList of ShellItem objects.</returns>
public List<ShellInfo> GetSubItems(WindowsAPI.IShellFolder ShellFolder, IntPtr pIDL)
{
List<ShellInfo> child = new List<ShellInfo>();
// Get the IEnumIDList interface pointer.
WindowsAPI.IEnumIDList pEnum = null;
//WindowsAPI.SHCONTF flags = WindowsAPI.SHCONTF.SHCONTF_FOLDERS | WindowsAPI.SHCONTF.SHCONTF_NONFOLDERS | WindowsAPI.SHCONTF.SHCONTF_INCLUDEHIDDEN; //フォルダあり
//WindowsAPI.SHCONTF flags = WindowsAPI.SHCONTF.SHCONTF_NONFOLDERS | WindowsAPI.SHCONTF.SHCONTF_INCLUDEHIDDEN; //ファイルのみ
WindowsAPI.SHCONTF flags = WindowsAPI.SHCONTF.SHCONTF_FOLDERS; //フォルダのみ
uint hRes = ShellFolder.EnumObjects(IntPtr.Zero, flags, out pEnum);
if (hRes != 0) Marshal.ThrowExceptionForHR((int)hRes);
// バッチサイズの設定
const uint batchSize = 128;
IntPtr[] childPIDLs = new IntPtr[batchSize];
int fetched = 0;
try {
while (true) {
uint result = pEnum.Next(batchSize, childPIDLs, out fetched);
if (result != 0 || fetched == 0) {
break; // 列挙が終了した場合
}
for (int i = 0; i < fetched; i++) {
ShellInfo sinf;
GetShellInfoFromPIDL(ShellFolder, pIDL, childPIDLs[i], out sinf);
child.Add(sinf);
// PIDL の解放
Marshal.FreeCoTaskMem(childPIDLs[i]);
childPIDLs[i] = IntPtr.Zero;
}
}
}
finally {
// 残っている PIDL を解放
for (int i = 0; i < fetched; i++) {
if (childPIDLs[i] != IntPtr.Zero) {
Marshal.FreeCoTaskMem(childPIDLs[i]);
}
}
// COM オブジェクトの解放
if (pEnum != null) {
Marshal.ReleaseComObject(pEnum);
}
}
return child;
}
/// <summary>
/// Gets the system path for this shell item.
/// </summary>
/// <returns>A path string.</returns>
public string GetPath(IntPtr pIDL)
{
StringBuilder strBuffer = new StringBuilder(256);
WindowsAPI.SHGetPathFromIDList(pIDL, strBuffer);
return strBuffer.ToString();
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
namespace ShellObjectsDemo2025
{
public class WindowsAPI
{
public const Int32 FILE_ATTRIBUTE_NORMAL = 0x80;
public static Guid IID_IShellFolder = new Guid("000214E6-0000-0000-C000-000000000046");
[DllImport("shell32.dll", CharSet = CharSet.Auto)]
public static extern int SHGetDesktopFolder(out IShellFolder ppshf);
[DllImport("shell32.dll", CharSet = CharSet.Auto)]
public static extern IntPtr SHGetFileInfo(IntPtr pIDL, uint dwFileAttributes, out SHFILEINFO psfi, uint cbFileInfo, SHGFI uFlags);
[DllImport("shell32.dll", CharSet = CharSet.Auto)]
public static extern Int32 SHGetSpecialFolderLocation(IntPtr hwndOwner, CSIDL nFolder, ref IntPtr ppidl);
[DllImport("shell32.dll", CharSet = CharSet.Auto)]
public static extern IntPtr ILCombine(IntPtr pIDLParent, IntPtr pIDLChild);
[DllImport("shell32.dll", CharSet = CharSet.Auto)]
public static extern IntPtr ILClone(IntPtr pidl);
[DllImport("shell32.dll", CharSet = CharSet.Auto)]
public static extern Int32 SHGetPathFromIDList(IntPtr pIDL, StringBuilder strPath);
[Flags()]
public enum SHGDFIL : int
{
SHGDFIL_FINDDATA = 1,
SHGDFIL_NETRESOURCE = 2,
SHGDFIL_DESCRIPTIONID = 3
}
[Flags]
public enum SHGDN : uint
{
SHGDN_NORMAL = 0x0000, // Default (display purpose)
SHGDN_INFOLDER = 0x0001, // Displayed under a folder (relative)
SHGDN_FOREDITING = 0x1000, // For in-place editing
SHGDN_FORADDRESSBAR = 0x4000, // UI friendly parsing name (remove ugly stuff)
SHGDN_FORPARSING = 0x8000, // Parsing name for ParseDisplayName()
}
[Flags]
public enum SHCONTF : uint
{
SHCONTF_CHECKING_FOR_CHILDREN = 0x0010,
SHCONTF_FOLDERS = 0x0020, // Only want folders enumerated (SFGAO_FOLDER)
SHCONTF_NONFOLDERS = 0x0040, // Include non folders
SHCONTF_INCLUDEHIDDEN = 0x0080, // Show items normally hidden
SHCONTF_INIT_ON_FIRST_NEXT = 0x0100, // Allow EnumObject() to return before validating enum
SHCONTF_NETPRINTERSRCH = 0x0200, // Hint that client is looking for printers
SHCONTF_SHAREABLE = 0x0400, // Hint that client is looking sharable resources (remote shares)
SHCONTF_STORAGE = 0x0800, // Include all items with accessible storage and their ancestors
SHCONTF_NAVIGATION_ENUM = 0x01000,
SHCONTF_FASTITEMS = 0x02000,
SHCONTF_FLATLIST = 0x04000,
SHCONTF_ENABLE_ASYNC = 0x08000,
SHCONTF_INCLUDESUPERHIDDEN = 0x10000,
}
[Flags]
public enum SFGAOF : uint
{
SFGAO_CANCOPY = 0x1, // Objects can be copied (DROPEFFECT_COPY)
SFGAO_CANMOVE = 0x2, // Objects can be moved (DROPEFFECT_MOVE)
SFGAO_CANLINK = 0x4, // Objects can be linked (DROPEFFECT_LINK)
SFGAO_STORAGE = 0x00000008, // Supports BindToObject(IID_IStorage)
SFGAO_CANRENAME = 0x00000010, // Objects can be renamed
SFGAO_CANDELETE = 0x00000020, // Objects can be deleted
SFGAO_HASPROPSHEET = 0x00000040, // Objects have property sheets
SFGAO_DROPTARGET = 0x00000100, // Objects are drop target
SFGAO_CAPABILITYMASK = 0x00000177,
SFGAO_SYSTEM = 0x00001000,
SFGAO_ENCRYPTED = 0x00002000, // Object is encrypted (use alt color)
SFGAO_ISSLOW = 0x00004000, // 'Slow' object
SFGAO_GHOSTED = 0x00008000, // Ghosted icon
SFGAO_LINK = 0x00010000, // Shortcut (link)
SFGAO_SHARE = 0x00020000, // Shared
SFGAO_READONLY = 0x00040000, // Read-only
SFGAO_HIDDEN = 0x00080000, // Hidden object
SFGAO_DISPLAYATTRMASK = 0x000FC000,
SFGAO_FILESYSANCESTOR = 0x10000000, // May contain children with SFGAO_FILESYSTEM
SFGAO_FOLDER = 0x20000000, // Support BindToObject(IID_IShellFolder)
SFGAO_FILESYSTEM = 0x40000000, // Is a win32 file system object (file/folder/root)
SFGAO_HASSUBFOLDER = 0x80000000, // May contain children with SFGAO_FOLDER
SFGAO_CONTENTSMASK = 0x80000000,
SFGAO_VALIDATE = 0x01000000, // Invalidate cached information
SFGAO_REMOVABLE = 0x02000000, // Is this removeable media?
SFGAO_COMPRESSED = 0x04000000, // Object is compressed (use alt color)
SFGAO_BROWSABLE = 0x08000000, // Supports IShellFolder, but only implements CreateViewObject() (non-folder view)
SFGAO_NONENUMERATED = 0x00100000, // Is a non-enumerated object
SFGAO_NEWCONTENT = 0x00200000, // Should show bold in explorer tree
SFGAO_CANMONIKER = 0x00400000, // Defunct
SFGAO_HASSTORAGE = 0x00400000, // Defunct
SFGAO_STREAM = 0x00400000, // Supports BindToObject(IID_IStream)
SFGAO_STORAGEANCESTOR = 0x00800000, // May contain children with SFGAO_STORAGE or SFGAO_STREAM
SFGAO_STORAGECAPMASK = 0x70C50008, // For determining storage capabilities, ie for open/save semantics
}
[Flags]
public enum STRRET : uint
{
STRRET_WSTR = 0,
STRRET_OFFSET = 0x1,
STRRET_CSTR = 0x2,
}
[Flags]
public enum SHGFI
{
SHGFI_ICON = 0x000000100,
SHGFI_DISPLAYNAME = 0x000000200,
SHGFI_TYPENAME = 0x000000400,
SHGFI_ATTRIBUTES = 0x000000800,
SHGFI_ICONLOCATION = 0x000001000,
SHGFI_EXETYPE = 0x000002000,
SHGFI_SYSICONINDEX = 0x000004000,
SHGFI_LINKOVERLAY = 0x000008000,
SHGFI_SELECTED = 0x000010000,
SHGFI_ATTR_SPECIFIED = 0x000020000,
SHGFI_LARGEICON = 0x000000000,
SHGFI_SMALLICON = 0x000000001,
SHGFI_OPENICON = 0x000000002,
SHGFI_SHELLICONSIZE = 0x000000004,
SHGFI_PIDL = 0x000000008,
SHGFI_USEFILEATTRIBUTES = 0x000000010,
SHGFI_ADDOVERLAYS = 0x000000020,
SHGFI_OVERLAYINDEX = 0x000000040
}
[Flags]
public enum CSIDL : uint
{
CSIDL_DESKTOP = 0x0000, // <desktop>
CSIDL_INTERNET = 0x0001, // Internet Explorer (icon on desktop)
CSIDL_PROGRAMS = 0x0002, // Start Menu\Programs
CSIDL_CONTROLS = 0x0003, // My Computer\Control Panel
CSIDL_PRINTERS = 0x0004, // My Computer\Printers
CSIDL_PERSONAL = 0x0005, // My Documents
CSIDL_FAVORITES = 0x0006, // <user name>\Favorites
CSIDL_STARTUP = 0x0007, // Start Menu\Programs\Startup
CSIDL_RECENT = 0x0008, // <user name>\Recent
CSIDL_SENDTO = 0x0009, // <user name>\SendTo
CSIDL_BITBUCKET = 0x000a, // <desktop>\Recycle Bin
CSIDL_STARTMENU = 0x000b, // <user name>\Start Menu
CSIDL_MYDOCUMENTS = 0x000c, // logical "My Documents" desktop icon
CSIDL_MYMUSIC = 0x000d, // "My Music" folder
CSIDL_MYVIDEO = 0x000e, // "My Videos" folder
CSIDL_DESKTOPDIRECTORY = 0x0010, // <user name>\Desktop
CSIDL_DRIVES = 0x0011, // My Computer
CSIDL_NETWORK = 0x0012, // Network Neighborhood (My Network Places)
CSIDL_NETHOOD = 0x0013, // <user name>\nethood
CSIDL_FONTS = 0x0014, // windows\fonts
CSIDL_TEMPLATES = 0x0015,
CSIDL_COMMON_STARTMENU = 0x0016, // All Users\Start Menu
CSIDL_COMMON_PROGRAMS = 0X0017, // All Users\Start Menu\Programs
CSIDL_COMMON_STARTUP = 0x0018, // All Users\Startup
CSIDL_COMMON_DESKTOPDIRECTORY = 0x0019, // All Users\Desktop
CSIDL_APPDATA = 0x001a, // <user name>\Application Data
CSIDL_PRINTHOOD = 0x001b, // <user name>\PrintHood
CSIDL_LOCAL_APPDATA = 0x001c, // <user name>\Local Settings\Applicaiton Data (non roaming)
CSIDL_ALTSTARTUP = 0x001d, // non localized startup
CSIDL_COMMON_ALTSTARTUP = 0x001e, // non localized common startup
CSIDL_COMMON_FAVORITES = 0x001f,
CSIDL_INTERNET_CACHE = 0x0020,
CSIDL_COOKIES = 0x0021,
CSIDL_HISTORY = 0x0022,
CSIDL_COMMON_APPDATA = 0x0023, // All Users\Application Data
CSIDL_WINDOWS = 0x0024, // GetWindowsDirectory()
CSIDL_SYSTEM = 0x0025, // GetSystemDirectory()
CSIDL_PROGRAM_FILES = 0x0026, // C:\Program Files
CSIDL_MYPICTURES = 0x0027, // C:\Program Files\My Pictures
CSIDL_PROFILE = 0x0028, // USERPROFILE
CSIDL_SYSTEMX86 = 0x0029, // x86 system directory on RISC
CSIDL_PROGRAM_FILESX86 = 0x002a, // x86 C:\Program Files on RISC
CSIDL_PROGRAM_FILES_COMMON = 0x002b, // C:\Program Files\Common
CSIDL_PROGRAM_FILES_COMMONX86 = 0x002c, // x86 Program Files\Common on RISC
CSIDL_COMMON_TEMPLATES = 0x002d, // All Users\Templates
CSIDL_COMMON_DOCUMENTS = 0x002e, // All Users\Documents
CSIDL_COMMON_ADMINTOOLS = 0x002f, // All Users\Start Menu\Programs\Administrative Tools
CSIDL_ADMINTOOLS = 0x0030, // <user name>\Start Menu\Programs\Administrative Tools
CSIDL_CONNECTIONS = 0x0031, // Network and Dial-up Connections
CSIDL_COMMON_MUSIC = 0x0035, // All Users\My Music
CSIDL_COMMON_PICTURES = 0x0036, // All Users\My Pictures
CSIDL_COMMON_VIDEO = 0x0037, // All Users\My Video
CSIDL_CDBURN_AREA = 0x003b // USERPROFILE\Local Settings\Application Data\Microsoft\CD Burning
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
public struct SHFILEINFO
{
public IntPtr hIcon;
public int iIcon;
public uint dwAttributes;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]
public string szDisplayName;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 80)]
public string szTypeName;
}
/// <summary>
/// managed equivalent of IShellFolder interface
/// Pinvoke.net / Mod by Arik Poznanski - pooya parsa
/// Msdn: http://msdn.microsoft.com/en-us/library/windows/desktop/bb775075(v=vs.85).aspx
/// Pinvoke: http://pinvoke.net/default.aspx/Interfaces/IShellFolder.html
/// </summary>
[ComImport]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
[Guid("000214E6-0000-0000-C000-000000000046")]
public interface IShellFolder
{
/// <summary>
/// Translates a file object's or folder's display name into an item identifier list.
/// Return value: error code, if any
/// </summary>
/// <param name="hwnd">Optional window handle</param>
/// <param name="pbc">Optional bind context that controls the parsing operation. This parameter is normally set to NULL. </param>
/// <param name="pszDisplayName">Null-terminated UNICODE string with the display name</param>
/// <param name="pchEaten">Pointer to a ULONG value that receives the number of characters of the display name that was parsed.</param>
/// <param name="ppidl"> Pointer to an ITEMIDLIST pointer that receives the item identifier list for the object.</param>
/// <param name="pdwAttributes">Optional parameter that can be used to query for file attributes.this can be values from the SFGAO enum</param>
//uint ParseDisplayName(IntPtr hwnd, IntPtr pbc, String pszDisplayName, out UInt32 pchEaten, out IntPtr ppidl, ref UInt32 pdwAttributes);
uint ParseDisplayName(IntPtr hwnd, IntPtr pbc, String pszDisplayName, out UInt32 pchEaten, out IntPtr ppidl, ref SFGAOF pdwAttributes);
/// <summary>
///Allows a client to determine the contents of a folder by creating an item identifier enumeration object and returning its IEnumIDList interface.
///Return value: error code, if any
/// </summary>
/// <param name="hwnd">If user input is required to perform the enumeration, this window handle should be used by the enumeration object as the parent window to take user input.</param>
/// <param name="grfFlags">Flags indicating which items to include in the enumeration. For a list of possible values, see the SHCONTF enum. </param>
/// <param name="ppenumIDList">Address that receives a pointer to the IEnumIDList interface of the enumeration object created by this method. </param>
uint EnumObjects(IntPtr hwnd, SHCONTF grfFlags, out IEnumIDList ppenumIDList);
//IEnumIDList EnumObjects(IntPtr hwnd, SHCONTF grfFlags);
/// <summary>
///Retrieves an IShellFolder object for a subfolder.
// Return value: error code, if any
/// </summary>
/// <param name="pidl">Address of an ITEMIDLIST structure (PIDL) that identifies the subfolder.</param>
/// <param name="pbc">Optional address of an IBindCtx interface on a bind context object to be used during this operation.</param>
/// <param name="riid">Identifier of the interface to return. </param>
/// <param name="ppv">Address that receives the interface pointer.</param>
uint BindToObject(IntPtr pidl, IntPtr pbc, [In] ref Guid riid, out IShellFolder ppv);
/// <summary>
/// Requests a pointer to an object's storage interface.
/// Return value: error code, if any
/// </summary>
/// <param name="pidl">Address of an ITEMIDLIST structure that identifies the subfolder relative to its parent folder. </param>
/// <param name="pbc">Optional address of an IBindCtx interface on a bind context object to be used during this operation.</param>
/// <param name="riid">Interface identifier (IID) of the requested storage interface.</param>
/// <param name="ppv"> Address that receives the interface pointer specified by riid.</param>
uint BindToStorage(IntPtr pidl, IntPtr pbc, [In] ref Guid riid, out IntPtr ppv);
/// <summary>
/// Determines the relative order of two file objects or folders, given
/// their item identifier lists. Return value: If this method is
/// successful, the CODE field of the HRESULT contains one of the
/// following values (the code can be retrived using the helper function
/// GetHResultCode): Negative A negative return value indicates that the first item should precede the second (pidl1 < pidl2).
////
///Positive A positive return value indicates that the first item should
///follow the second (pidl1 > pidl2). Zero A return value of zero
///indicates that the two items are the same (pidl1 = pidl2).
/// </summary>
/// <param name="lParam">Value that specifies how the comparison should be performed. The lower Sixteen bits of lParam define the sorting rule.
/// The upper sixteen bits of lParam are used for flags that modify the sorting rule. values can be from the SHCIDS enum
/// </param>
/// <param name="pidl1">Pointer to the first item's ITEMIDLIST structure.</param>
/// <param name="pidl2"> Pointer to the second item's ITEMIDLIST structure.</param>
/// <returns></returns>
[PreserveSig]
Int32 CompareIDs(Int32 lParam, IntPtr pidl1, IntPtr pidl2);
/// <summary>
/// Requests an object that can be used to obtain information from or interact
/// with a folder object.
/// Return value: error code, if any
/// </summary>
/// <param name="hwndOwner">Handle to the owner window.</param>
/// <param name="riid">Identifier of the requested interface.</param>
/// <param name="ppv">Address of a pointer to the requested interface. </param>
uint CreateViewObject(IntPtr hwndOwner, [In] ref Guid riid, out IntPtr ppv);
/// <summary>
/// Retrieves the attributes of one or more file objects or subfolders.
/// Return value: error code, if any
/// </summary>
/// <param name="cidl">Number of file objects from which to retrieve attributes. </param>
/// <param name="apidl">Address of an array of pointers to ITEMIDLIST structures, each of which uniquely identifies a file object relative to the parent folder.</param>
/// <param name="rgfInOut">Address of a single ULONG value that, on entry contains the attributes that the caller is
/// requesting. On exit, this value contains the requested attributes that are common to all of the specified objects. this value can be from the SFGAO enum
/// </param>
uint GetAttributesOf(UInt32 cidl, [MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 0)] IntPtr[] apidl, ref SFGAOF rgfInOut);
/// <summary>
/// Retrieves an OLE interface that can be used to carry out actions on the
/// specified file objects or folders. Return value: error code, if any
/// </summary>
/// <param name="hwndOwner">Handle to the owner window that the client should specify if it displays a dialog box or message box.</param>
/// <param name="cidl">Number of file objects or subfolders specified in the apidl parameter. </param>
/// <param name="apidl">Address of an array of pointers to ITEMIDLIST structures, each of which uniquely identifies a file object or subfolder relative to the parent folder.</param>
/// <param name="riid">Identifier of the COM interface object to return.</param>
/// <param name="rgfReserved"> Reserved. </param>
/// <param name="ppv">Pointer to the requested interface.</param>
uint GetUIObjectOf(IntPtr hwndOwner, UInt32 cidl, [MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 1)] IntPtr[] apidl, [In] ref Guid riid, UInt32 rgfReserved, out IntPtr ppv);
/// <summary>
/// Retrieves the display name for the specified file object or subfolder.
/// Return value: error code, if any
/// </summary>
/// <param name="pidl">Address of an ITEMIDLIST structure (PIDL) that uniquely identifies the file object or subfolder relative to the parent folder. </param>
/// <param name="uFlags">Flags used to request the type of display name to return. For a list of possible values. </param>
/// <param name="pName"> Address of a STRRET structure in which to return the display name.</param>
uint GetDisplayNameOf(IntPtr pidl, SHGDN uFlags, out STRRET pName);
/// <summary>
/// Sets the display name of a file object or subfolder, changing the item
/// identifier in the process.
/// Return value: error code, if any
/// </summary>
/// <param name="hwnd"> Handle to the owner window of any dialog or message boxes that the client displays.</param>
/// <param name="pidl"> Pointer to an ITEMIDLIST structure that uniquely identifies the file object or subfolder relative to the parent folder. </param>
/// <param name="pszName"> Pointer to a null-terminated string that specifies the new display name.</param>
/// <param name="uFlags">Flags indicating the type of name specified by the lpszName parameter. For a list of possible values, see the description of the SHGNO enum.</param>
/// <param name="ppidlOut"></param>
uint SetNameOf(IntPtr hwnd, IntPtr pidl, String pszName, SHGDN uFlags, out IntPtr ppidlOut);
}
[ComImport]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
[Guid("000214F2-0000-0000-C000-000000000046")]
public interface IEnumIDList
{
// Retrieves the specified number of item identifiers in the enumeration sequence and advances the current position by the number of items retrieved.
[PreserveSig]
uint Next(
uint celt, // Number of elements in the array pointed to by the rgelt parameter.
[Out, MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 0)] IntPtr[] rgelt, // Address of an array of ITEMIDLIST pointers that receives the item identifiers. The implementation must allocate these item identifiers using the Shell's allocator (retrieved by the SHGetMalloc function). The calling application is responsible for freeing the item identifiers using the Shell's allocator.
out int pceltFetched // Address of a value that receives a count of the item identifiers actually returned in rgelt. The count can be smaller than the value specified in the celt parameter. This parameter can be NULL only if celt is one.
);
// Skips over the specified number of elements in the enumeration sequence.
[PreserveSig()]
uint Skip(
uint celt // Number of item identifiers to skip.
);
// Returns to the beginning of the enumeration sequence.
[PreserveSig()]
uint Reset();
// Creates a new item enumeration object with the same contents and state as the current one.
[PreserveSig()]
uint Clone(
out IEnumIDList ppenum // Address of a pointer to the new enumeration object. The calling application must eventually free the new object by calling its Release member function.
);
}
}
}
ボタンのクリックをすると、SHGetDesktopFolder SHGetSpecialFolderLocation Windows API を呼び出して
デスクトップシェルフォルダオブジェクトと、デスクトップのpIDLを取得します。
WindowsAPI.IShellFolder DesktopShellFolder;
IntPtr Desktop_pIDL = IntPtr.Zero;
WindowsAPI.SHGetDesktopFolder(out DesktopShellFolder);
WindowsAPI.SHGetSpecialFolderLocation(IntPtr.Zero, WindowsAPI.CSIDL.CSIDL_DESKTOP, ref Desktop_pIDL);
取得したデスクトップシェルフォルダオブジェクトと、デスクトップのpIDLを用いて、子要素を取得します。
取得した子要素をテキストボックスに表示します。
List<ShellInfo> childinf = GetSubItems(DesktopShellFolder, Desktop_pIDL);
foreach (ShellInfo ci in childinf) {
textBox1.Text += ci.DisplayName + "\r\n";
}
GetSubItems() 関数内では、シェルフォルダオブジェクトのEnumObjects()メソッドを呼び出し、子要素を取得します。
今回はフォルダ要素のみを取得するため、SHCONTF のパラメータには、SHCONTF_FOLDERS のみを指定しています。
List<ShellInfo> child = new List<ShellInfo>();
// Get the IEnumIDList interface pointer.
WindowsAPI.IEnumIDList pEnum = null;
//WindowsAPI.SHCONTF flags = WindowsAPI.SHCONTF.SHCONTF_FOLDERS | WindowsAPI.SHCONTF.SHCONTF_NONFOLDERS | WindowsAPI.SHCONTF.SHCONTF_INCLUDEHIDDEN; //フォルダあり
//WindowsAPI.SHCONTF flags = WindowsAPI.SHCONTF.SHCONTF_NONFOLDERS | WindowsAPI.SHCONTF.SHCONTF_INCLUDEHIDDEN; //ファイルのみ
WindowsAPI.SHCONTF flags = WindowsAPI.SHCONTF.SHCONTF_FOLDERS; //フォルダのみ
uint hRes = ShellFolder.EnumObjects(IntPtr.Zero, flags, out pEnum);
if (hRes != 0) Marshal.ThrowExceptionForHR((int)hRes);
IEnumIDListから子要素の情報を取得して、ShellInfoオブジェクトを作成し、リストに挿入します。
// バッチサイズの設定
const uint batchSize = 128;
IntPtr[] childPIDLs = new IntPtr[batchSize];
int fetched = 0;
try {
while (true) {
uint result = pEnum.Next(batchSize, childPIDLs, out fetched);
if (result != 0 || fetched == 0) {
break; // 列挙が終了した場合
}
for (int i = 0; i < fetched; i++) {
ShellInfo sinf;
GetShellInfoFromPIDL(ShellFolder, pIDL, childPIDLs[i], out sinf);
child.Add(sinf);
// PIDL の解放
Marshal.FreeCoTaskMem(childPIDLs[i]);
childPIDLs[i] = IntPtr.Zero;
}
}
}
finally {
// 残っている PIDL を解放
for (int i = 0; i < fetched; i++) {
if (childPIDLs[i] != IntPtr.Zero) {
Marshal.FreeCoTaskMem(childPIDLs[i]);
}
}
// COM オブジェクトの解放
if (pEnum != null) {
Marshal.ReleaseComObject(pEnum);
}
}
return child;
プロジェクトを実行します。下図のウィンドウが表示されます。
ボタンをクリックします。デスクトップ項目にあるフォルダ要素の一覧が表示されます。
下図のUIを作成します。ボタンを2つ、複数行テキストボックスを1つ配置しています。(今回のプログラムではボタンは1つしか利用しません。)
下記のコードを記述します。
シェルAPIのコードはCodeProjectのこちらの記事の定義をもとにしています。
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using ShellObjects;
namespace ShellObjectsDemo
{
public partial class FormDesktopShellFolder : Form
{
ShellItem m_shDesktop;
public FormDesktopShellFolder()
{
InitializeComponent();
m_shDesktop = new ShellItem();
}
private void button2_Click(object sender, EventArgs e)
{
List<ShellItem> arrChildren = m_shDesktop.GetSubFolders();
foreach (ShellItem shChild in arrChildren) {
textBox1.Text += shChild.DisplayName + "\r\n";
}
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Runtime.InteropServices;
//using System.Collections;
using System.Windows.Forms;
namespace ShellObjects
{
public class ShellItem
{
// Sets a flag specifying whether or not we've got the IShellFolder interface for the Desktop.
private static Boolean m_bHaveRootShell = false;
/// <summary>
/// Constructor. Creates the ShellItem object for the Desktop.
/// </summary>
public ShellItem()
{
// new ShellItem() can only be called once.
if (m_bHaveRootShell)
throw new Exception("The Desktop shell item already exists so cannot be created again.");
// Obtain the root IShellFolder interface.
int hRes = ShellWindowsAPI.SHGetDesktopFolder(ref m_shRootShell);
if (hRes != 0)
Marshal.ThrowExceptionForHR(hRes);
// Now get the PIDL for the Desktop shell item.
hRes = ShellWindowsAPI.SHGetSpecialFolderLocation(IntPtr.Zero, ShellWindowsAPI.CSIDL.CSIDL_DESKTOP, ref m_pIDL);
if (hRes != 0)
Marshal.ThrowExceptionForHR(hRes);
// Now retrieve some attributes for the root shell item.
ShellWindowsAPI.SHFILEINFO shInfo = new ShellWindowsAPI.SHFILEINFO();
ShellWindowsAPI.SHGetFileInfo(m_pIDL, 0, out shInfo, (uint)Marshal.SizeOf(shInfo),
ShellWindowsAPI.SHGFI.SHGFI_DISPLAYNAME |
ShellWindowsAPI.SHGFI.SHGFI_PIDL |
ShellWindowsAPI.SHGFI.SHGFI_SMALLICON |
ShellWindowsAPI.SHGFI.SHGFI_SYSICONINDEX
);
// Set the arributes to object properties.
DisplayName = shInfo.szDisplayName;
IconIndex = shInfo.iIcon;
IsFolder = true;
HasSubFolder = true;
Path = GetPath();
// Internal with no set{} mutator.
m_shShellFolder = RootShellFolder;
m_bHaveRootShell = true;
}
/// <summary>
/// Constructor. Create a sub-item shell item object.
/// </summary>
/// <param name="shDesktop">IShellFolder interface of the Desktop</param>
/// <param name="pIDL">The fully qualified PIDL for this shell item</param>
/// <param name="shParent">The ShellItem object for this item's parent</param>
public ShellItem(ShellWindowsAPI.IShellFolder shDesktop, IntPtr pIDL, ShellItem shParent)
{
// We need the Desktop shell item to exist first.
if (m_bHaveRootShell == false)
throw new Exception("The root shell item must be created before creating a sub-item");
// Create the FQ PIDL for this new item.
m_pIDL = ShellWindowsAPI.ILCombine(shParent.PIDL, pIDL);
// Get the properties of this item.
ShellWindowsAPI.SFGAOF uFlags = ShellWindowsAPI.SFGAOF.SFGAO_FOLDER | ShellWindowsAPI.SFGAOF.SFGAO_HASSUBFOLDER;
// Here we get some basic attributes.
shDesktop.GetAttributesOf(1, out m_pIDL, out uFlags);
IsFolder = Convert.ToBoolean(uFlags & ShellWindowsAPI.SFGAOF.SFGAO_FOLDER);
HasSubFolder = Convert.ToBoolean(uFlags & ShellWindowsAPI.SFGAOF.SFGAO_HASSUBFOLDER);
// Now we want to get extended attributes such as the icon index etc.
ShellWindowsAPI.SHFILEINFO shInfo = new ShellWindowsAPI.SHFILEINFO();
ShellWindowsAPI.SHGFI vFlags =
ShellWindowsAPI.SHGFI.SHGFI_SMALLICON |
ShellWindowsAPI.SHGFI.SHGFI_SYSICONINDEX |
ShellWindowsAPI.SHGFI.SHGFI_PIDL |
ShellWindowsAPI.SHGFI.SHGFI_DISPLAYNAME;
ShellWindowsAPI.SHGetFileInfo(m_pIDL, 0, out shInfo, (uint)Marshal.SizeOf(shInfo), vFlags);
DisplayName = shInfo.szDisplayName;
IconIndex = shInfo.iIcon;
Path = GetPath();
// Create the IShellFolder interface for this item.
if (IsFolder)
{
uint hRes = shParent.m_shShellFolder.BindToObject(pIDL, IntPtr.Zero, ref ShellWindowsAPI.IID_IShellFolder, out m_shShellFolder);
if (hRes != 0)
Marshal.ThrowExceptionForHR((int)hRes);
}
}
~ShellItem()
{
// Release the IShellFolder interface of this shell item.
if (m_shShellFolder != null)
Marshal.ReleaseComObject(m_shShellFolder);
// Free the PIDL too.
if (!m_pIDL.Equals(IntPtr.Zero))
Marshal.FreeCoTaskMem(m_pIDL);
GC.SuppressFinalize(this);
}
/// <summary>
/// Gets the system path for this shell item.
/// </summary>
/// <returns>A path string.</returns>
public string GetPath()
{
StringBuilder strBuffer = new StringBuilder(256);
ShellWindowsAPI.SHGetPathFromIDList(
m_pIDL,
strBuffer
);
return strBuffer.ToString();
}
/// <summary>
/// Retrieves an array of ShellItem objects for sub-folders of this shell item.
/// </summary>
/// <returns>ArrayList of ShellItem objects.</returns>
public List<ShellItem> GetSubFolders()
{
// Make sure we have a folder.
if (IsFolder == false)
throw new Exception("Unable to retrieve sub-folders for a non-folder.");
List<ShellItem> arrChildren = new List<ShellItem>();
try
{
// Get the IEnumIDList interface pointer.
ShellWindowsAPI.IEnumIDList pEnum = null;
uint hRes = ShellFolder.EnumObjects(IntPtr.Zero, ShellWindowsAPI.SHCONTF.SHCONTF_FOLDERS, out pEnum);
if (hRes != 0)
Marshal.ThrowExceptionForHR((int)hRes);
IntPtr pIDL = IntPtr.Zero;
Int32 iGot = 0;
// Grab the first enumeration.
pEnum.Next(1, out pIDL, out iGot);
// Then continue with all the rest.
while (!pIDL.Equals(IntPtr.Zero) && iGot == 1)
{
// Create the new ShellItem object.
arrChildren.Add(new ShellItem(m_shRootShell, pIDL, this));
// Free the PIDL and reset counters.
Marshal.FreeCoTaskMem(pIDL);
pIDL = IntPtr.Zero;
iGot = 0;
// Grab the next item.
pEnum.Next(1, out pIDL, out iGot);
}
// Free the interface pointer.
if (pEnum != null)
Marshal.ReleaseComObject(pEnum);
}
catch (Exception ex)
{
System.Windows.Forms.MessageBox.Show(ex.Message, "Error:",
System.Windows.Forms.MessageBoxButtons.OK,
System.Windows.Forms.MessageBoxIcon.Error
);
}
return arrChildren;
}
/// <summary>
/// Gets or set the display name for this shell item.
/// </summary>
public string DisplayName
{
get { return m_strDisplayName; }
set { m_strDisplayName = value; }
}
string m_strDisplayName = "";
/// <summary>
/// Gets or sets the system image list icon index for this shell item.
/// </summary>
public Int32 IconIndex
{
get { return m_iIconIndex; }
set { m_iIconIndex = value; }
}
Int32 m_iIconIndex = -1;
/// <summary>
/// Gets the IShellFolder interface of the Desktop.
/// </summary>
public ShellWindowsAPI.IShellFolder RootShellFolder
{
get { return m_shRootShell; }
}
static ShellWindowsAPI.IShellFolder m_shRootShell = null;
/// <summary>
/// Gets the IShellFolder interface of this shell item.
/// </summary>
public ShellWindowsAPI.IShellFolder ShellFolder
{
get { return m_shShellFolder; }
}
ShellWindowsAPI.IShellFolder m_shShellFolder = null;
/// <summary>
/// Gets the fully qualified PIDL for this shell item.
/// </summary>
public IntPtr PIDL
{
get { return m_pIDL; }
}
IntPtr m_pIDL = IntPtr.Zero;
/// <summary>
/// Gets or sets a boolean indicating whether this shell item is a folder.
/// </summary>
public bool IsFolder
{
get { return m_bIsFolder; }
set { m_bIsFolder = value; }
}
bool m_bIsFolder = false;
/// <summary>
/// Gets or sets a boolean indicating whether this shell item has any sub-folders.
/// </summary>
public bool HasSubFolder
{
get { return m_bHasSubFolder; }
set { m_bHasSubFolder = value; }
}
bool m_bHasSubFolder = false;
/// <summary>
/// Gets or sets the system path for this shell item.
/// </summary>
public string Path
{
get { return m_strPath; }
set { m_strPath = value; }
}
string m_strPath = "";
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Runtime.InteropServices;
namespace ShellObjects
{
public class ShellWindowsAPI
{
public const Int32 FILE_ATTRIBUTE_NORMAL = 0x80;
public static Guid IID_IShellFolder = new Guid("000214E6-0000-0000-C000-000000000046");
[DllImport("user32.dll")]
public static extern Int32 SendMessage(IntPtr pWnd, UInt32 uMsg, UInt32 wParam, IntPtr lParam);
[DllImport("shell32.dll")]
public static extern Int32 SHGetDesktopFolder(ref IShellFolder ppshf);
[DllImport("shell32.dll")]
public static extern IntPtr SHGetFileInfo(string pszPath, uint dwFileAttribs, out SHFILEINFO psfi, uint cbFileInfo, SHGFI uFlags);
[DllImport("shell32.dll")]
public static extern IntPtr SHGetFileInfo(IntPtr pIDL, uint dwFileAttributes, out SHFILEINFO psfi, uint cbFileInfo, SHGFI uFlags);
[DllImport("shell32.dll")]
public static extern Int32 SHGetSpecialFolderLocation(IntPtr hwndOwner, CSIDL nFolder, ref IntPtr ppidl);
[DllImport("shell32.dll")]
public static extern IntPtr ILCombine(IntPtr pIDLParent, IntPtr pIDLChild);
[DllImport("shell32.dll")]
public static extern Int32 SHGetPathFromIDList(IntPtr pIDL, StringBuilder strPath);
[Flags]
public enum SHGNO : uint
{
SHGDN_NORMAL = 0x0000, // Default (display purpose)
SHGDN_INFOLDER = 0x0001, // Displayed under a folder (relative)
SHGDN_FOREDITING = 0x1000, // For in-place editing
SHGDN_FORADDRESSBAR = 0x4000, // UI friendly parsing name (remove ugly stuff)
SHGDN_FORPARSING = 0x8000, // Parsing name for ParseDisplayName()
}
[Flags]
public enum SHCONTF : uint
{
SHCONTF_FOLDERS = 0x0020, // Only want folders enumerated (SFGAO_FOLDER)
SHCONTF_NONFOLDERS = 0x0040, // Include non folders
SHCONTF_INCLUDEHIDDEN = 0x0080, // Show items normally hidden
SHCONTF_INIT_ON_FIRST_NEXT = 0x0100, // Allow EnumObject() to return before validating enum
SHCONTF_NETPRINTERSRCH = 0x0200, // Hint that client is looking for printers
SHCONTF_SHAREABLE = 0x0400, // Hint that client is looking sharable resources (remote shares)
SHCONTF_STORAGE = 0x0800, // Include all items with accessible storage and their ancestors
}
[Flags]
public enum SFGAOF : uint
{
SFGAO_CANCOPY = 0x1, // Objects can be copied (DROPEFFECT_COPY)
SFGAO_CANMOVE = 0x2, // Objects can be moved (DROPEFFECT_MOVE)
SFGAO_CANLINK = 0x4, // Objects can be linked (DROPEFFECT_LINK)
SFGAO_STORAGE = 0x00000008, // Supports BindToObject(IID_IStorage)
SFGAO_CANRENAME = 0x00000010, // Objects can be renamed
SFGAO_CANDELETE = 0x00000020, // Objects can be deleted
SFGAO_HASPROPSHEET = 0x00000040, // Objects have property sheets
SFGAO_DROPTARGET = 0x00000100, // Objects are drop target
SFGAO_CAPABILITYMASK = 0x00000177,
SFGAO_ENCRYPTED = 0x00002000, // Object is encrypted (use alt color)
SFGAO_ISSLOW = 0x00004000, // 'Slow' object
SFGAO_GHOSTED = 0x00008000, // Ghosted icon
SFGAO_LINK = 0x00010000, // Shortcut (link)
SFGAO_SHARE = 0x00020000, // Shared
SFGAO_READONLY = 0x00040000, // Read-only
SFGAO_HIDDEN = 0x00080000, // Hidden object
SFGAO_DISPLAYATTRMASK = 0x000FC000,
SFGAO_FILESYSANCESTOR = 0x10000000, // May contain children with SFGAO_FILESYSTEM
SFGAO_FOLDER = 0x20000000, // Support BindToObject(IID_IShellFolder)
SFGAO_FILESYSTEM = 0x40000000, // Is a win32 file system object (file/folder/root)
SFGAO_HASSUBFOLDER = 0x80000000, // May contain children with SFGAO_FOLDER
SFGAO_CONTENTSMASK = 0x80000000,
SFGAO_VALIDATE = 0x01000000, // Invalidate cached information
SFGAO_REMOVABLE = 0x02000000, // Is this removeable media?
SFGAO_COMPRESSED = 0x04000000, // Object is compressed (use alt color)
SFGAO_BROWSABLE = 0x08000000, // Supports IShellFolder, but only implements CreateViewObject() (non-folder view)
SFGAO_NONENUMERATED = 0x00100000, // Is a non-enumerated object
SFGAO_NEWCONTENT = 0x00200000, // Should show bold in explorer tree
SFGAO_CANMONIKER = 0x00400000, // Defunct
SFGAO_HASSTORAGE = 0x00400000, // Defunct
SFGAO_STREAM = 0x00400000, // Supports BindToObject(IID_IStream)
SFGAO_STORAGEANCESTOR = 0x00800000, // May contain children with SFGAO_STORAGE or SFGAO_STREAM
SFGAO_STORAGECAPMASK = 0x70C50008, // For determining storage capabilities, ie for open/save semantics
}
[Flags]
public enum STRRET : uint
{
STRRET_WSTR = 0,
STRRET_OFFSET = 0x1,
STRRET_CSTR = 0x2,
}
[Flags]
public enum SHGFI
{
SHGFI_ICON = 0x000000100,
SHGFI_DISPLAYNAME = 0x000000200,
SHGFI_TYPENAME = 0x000000400,
SHGFI_ATTRIBUTES = 0x000000800,
SHGFI_ICONLOCATION = 0x000001000,
SHGFI_EXETYPE = 0x000002000,
SHGFI_SYSICONINDEX = 0x000004000,
SHGFI_LINKOVERLAY = 0x000008000,
SHGFI_SELECTED = 0x000010000,
SHGFI_ATTR_SPECIFIED = 0x000020000,
SHGFI_LARGEICON = 0x000000000,
SHGFI_SMALLICON = 0x000000001,
SHGFI_OPENICON = 0x000000002,
SHGFI_SHELLICONSIZE = 0x000000004,
SHGFI_PIDL = 0x000000008,
SHGFI_USEFILEATTRIBUTES = 0x000000010,
SHGFI_ADDOVERLAYS = 0x000000020,
SHGFI_OVERLAYINDEX = 0x000000040
}
[Flags]
public enum CSIDL : uint
{
CSIDL_DESKTOP = 0x0000,
CSIDL_WINDOWS = 0x0024
}
public struct SHFILEINFO
{
public IntPtr hIcon;
public int iIcon;
public uint dwAttributes;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]
public string szDisplayName;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 80)]
public string szTypeName;
}
[ComImport]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
[Guid("000214E6-0000-0000-C000-000000000046")]
public interface IShellFolder
{
// Translates a file object's or folder's display name into an item identifier list.
// Return value: error code, if any
[PreserveSig()]
uint ParseDisplayName(
IntPtr hwnd, // Optional window handle
IntPtr pbc, // Optional bind context that controls the parsing operation. This parameter is normally set to NULL.
[In(), MarshalAs(UnmanagedType.LPWStr)]
string pszDisplayName, // Null-terminated UNICODE string with the display name.
out uint pchEaten, // Pointer to a ULONG value that receives the number of characters of the display name that was parsed.
out IntPtr ppidl, // Pointer to an ITEMIDLIST pointer that receives the item identifier list for the object.
ref uint pdwAttributes); // Optional parameter that can be used to query for file attributes. This can be values from the SFGAO enum
// Allows a client to determine the contents of a folder by creating an item identifier enumeration object and returning its IEnumIDList interface.
// Return value: error code, if any
[PreserveSig()]
uint EnumObjects(
IntPtr hwnd, // If user input is required to perform the enumeration, this window handle should be used by the enumeration object as the parent window to take user input.
SHCONTF grfFlags, // Flags indicating which items to include in the enumeration. For a list of possible values, see the SHCONTF enum.
out IEnumIDList ppenumIDList); // Address that receives a pointer to the IEnumIDList interface of the enumeration object created by this method.
// Retrieves an IShellFolder object for a subfolder.
// Return value: error code, if any
[PreserveSig()]
uint BindToObject(
IntPtr pidl, // Address of an ITEMIDLIST structure (PIDL) that identifies the subfolder.
IntPtr pbc, // Optional address of an IBindCtx interface on a bind context object to be used during this operation.
[In()]
ref Guid riid, // Identifier of the interface to return.
out IShellFolder ppv); // Address that receives the interface pointer.
// Requests a pointer to an object's storage interface.
// Return value: error code, if any
[PreserveSig()]
uint BindToStorage(
IntPtr pidl, // Address of an ITEMIDLIST structure that identifies the subfolder relative to its parent folder.
IntPtr pbc, // Optional address of an IBindCtx interface on a bind context object to be used during this operation.
[In()]
ref Guid riid, // Interface identifier (IID) of the requested storage interface.
[MarshalAs(UnmanagedType.Interface)]
out object ppv); // Address that receives the interface pointer specified by riid.
// Determines the relative order of two file objects or folders, given their item identifier lists.
// Return value: If this method is successful, the CODE field of the HRESULT contains one of the following values (the code can be retrived using the helper function GetHResultCode)...
// A negative return value indicates that the first item should precede the second (pidl1 < pidl2).
// A positive return value indicates that the first item should follow the second (pidl1 > pidl2). Zero A return value of zero indicates that the two items are the same (pidl1 = pidl2).
[PreserveSig()]
int CompareIDs(
int lParam, // Value that specifies how the comparison should be performed. The lower sixteen bits of lParam define the sorting rule.
// The upper sixteen bits of lParam are used for flags that modify the sorting rule. values can be from the SHCIDS enum
IntPtr pidl1, // Pointer to the first item's ITEMIDLIST structure.
IntPtr pidl2); // Pointer to the second item's ITEMIDLIST structure.
// Requests an object that can be used to obtain information from or interact with a folder object.
// Return value: error code, if any
[PreserveSig()]
uint CreateViewObject(
IntPtr hwndOwner, // Handle to the owner window.
[In()]
ref Guid riid, // Identifier of the requested interface.
[MarshalAs(UnmanagedType.Interface)]
out object ppv); // Address of a pointer to the requested interface.
// Retrieves the attributes of one or more file objects or subfolders.
// Return value: error code, if any
[PreserveSig()]
uint GetAttributesOf(
int cidl, // Number of file objects from which to retrieve attributes.
out IntPtr apidl, // Address of an array of pointers to ITEMIDLIST structures, each of which uniquely identifies a file object relative to the parent folder.
out SFGAOF rgfInOut); // Address of a single ULONG value that, on entry, contains the attributes that the caller is requesting. On exit, this value contains the requested attributes that are common to all of the specified objects. this value can be from the SFGAO enum
// Retrieves an OLE interface that can be used to carry out actions on the specified file objects or folders.
// Return value: error code, if any
[PreserveSig()]
uint GetUIObjectOf(
IntPtr hwndOwner, // Handle to the owner window that the client should specify if it displays a dialog box or message box.
int cidl, // Number of file objects or subfolders specified in the apidl parameter.
[In(), MarshalAs(UnmanagedType.LPArray)] IntPtr[]
apidl, // Address of an array of pointers to ITEMIDLIST structures, each of which uniquely identifies a file object or subfolder relative to the parent folder.
[In()]
ref Guid riid, // Identifier of the COM interface object to return.
IntPtr rgfReserved, // Reserved.
[MarshalAs(UnmanagedType.Interface)]
out object ppv); // Pointer to the requested interface.
// Retrieves the display name for the specified file object or subfolder.
// Return value: error code, if any
[PreserveSig()]
uint GetDisplayNameOf(
IntPtr pidl, // Address of an ITEMIDLIST structure (PIDL) that uniquely identifies the file object or subfolder relative to the parent folder.
SHGNO uFlags, // Flags used to request the type of display name to return. For a list of possible values.
out STRRET pName); // Address of a STRRET structure in which to return the display name.
// Sets the display name of a file object or subfolder, changing the item identifier in the process.
// Return value: error code, if any
[PreserveSig()]
uint SetNameOf(
IntPtr hwnd, // Handle to the owner window of any dialog or message boxes that the client displays.
IntPtr pidl, // Pointer to an ITEMIDLIST structure that uniquely identifies the file object or subfolder relative to the parent folder.
[In(), MarshalAs(UnmanagedType.LPWStr)]
string pszName, // Pointer to a null-terminated string that specifies the new display name.
SHGNO uFlags, // Flags indicating the type of name specified by the lpszName parameter. For a list of possible values, see the description of the SHGNO enum.
out IntPtr ppidlOut); // Address of a pointer to an ITEMIDLIST structure which receives the new ITEMIDLIST.
}
[ComImport]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
[Guid("000214F2-0000-0000-C000-000000000046")]
public interface IEnumIDList
{
// Retrieves the specified number of item identifiers in the enumeration sequence and advances the current position by the number of items retrieved.
[PreserveSig()]
uint Next(
uint celt, // Number of elements in the array pointed to by the rgelt parameter.
out IntPtr rgelt, // Address of an array of ITEMIDLIST pointers that receives the item identifiers. The implementation must allocate these item identifiers using the Shell's allocator (retrieved by the SHGetMalloc function).
// The calling application is responsible for freeing the item identifiers using the Shell's allocator.
out Int32 pceltFetched // Address of a value that receives a count of the item identifiers actually returned in rgelt. The count can be smaller than the value specified in the celt parameter. This parameter can be NULL only if celt is one.
);
// Skips over the specified number of elements in the enumeration sequence.
[PreserveSig()]
uint Skip(
uint celt // Number of item identifiers to skip.
);
// Returns to the beginning of the enumeration sequence.
[PreserveSig()]
uint Reset();
// Creates a new item enumeration object with the same contents and state as the current one.
[PreserveSig()]
uint Clone(
out IEnumIDList ppenum // Address of a pointer to the new enumeration object. The calling application must eventually free the new object by calling its Release member function.
);
}
}
}
ShellWindowsAPI.cs, ShellItem.csは今回、クラスライブラリの別プロジェクト"ShellObjects"に分けてあります。
フォームのあるプロジェクトから参照設定で"ShellObjects"を参照してusing で"ShellObjects"を指定します。
今回のライブラリは、ShellItemのインスタンスを一つしか作成できない仕様のため、ShellItemはクラスのメンバ変数で宣言します。
ShellItem m_shDesktop;
プロジェクトを実行します。下図のウィンドウが表示されます。
[button2]をクリックします。デスクトップの子フォルダの一覧が表示されます。フォルダだけでなく、「ゴミ箱」「コントロールパネル」「PC」(マイコンピューター)などのフォルダでないオブジェクトも一覧に含まれています。
Windows 95, Windows 2000, Windows XP, などの古いWindowsではエクスプローラーのデスクトップと
デスクトップシェルフォルダの子要素はほぼ一致していましたが、最新のWindowsではデスクトップシェルフォルダとデスクトップの見え方は
一致しないです。
エクスプローラーで表示した場合には、デスクトップに配置してあるファイルしか表示されていないです。
一方シェルAPIでデスクトップシェルフォルダの子要素を取得した場合には、デスクトップに配置してあるファイルに加えて、
PC,コントロールパネル、ダウンロードフォルダ、ホーム、などの項目も表示されます。Windowsのエクスプローラーでは、
ホーム、ダウンロード、ドキュメント、ピクチャ、ミュージック、ビデオのフォルダは、デスクトップと同じ階層で見えていましたが、
シェルAPIではデスクトップのサブフォルダとして表示されることがわかります。
