C # получить эскиз из файла через windows api

Пробежал через это сегодня – ему уже несколько месяцев, но для меня это сделало для меня (на Win7, извлечение миниатюр в файлах MPEG-4):

• Источник: https://github.com/dbarros/WindowsAPICodePack
• Nuget: https://www.nuget.org/packages/WindowsAPICodePack-Shell

Код:

ShellFile shellFile = ShellFile.FromFilePath(pathToYourFile); Bitmap shellThumb = shellFile.Thumbnail.ExtraLargeBitmap; 

Надеюсь, поможет!

Миниатюры Microsoft Office в SharePoint по адресу http://msdn.microsoft.com/en-us/library/aa289172(VS.71).aspx . это именно то, что вы хотите. (Мне не удалось преобразовать код VB.NET в C #, используя http://www.developerfusion.com/tools/convert/vb-to-csharp/ .)

Что касается кода, который вы отправили в своем ответе, извлечение эскизов с помощью командной оболочки по адресу http://www.vbaccelerator.com/home/net/code/libraries/Shell_Projects/Thumbnail_Extraction/article.asp – это оригинальная статья, из которой код. Я считаю, что почти все образцы IExtractImage (вы находите поиск) основаны на коде этой статьи из-за соглашения об именах, комментариев и т. Д., Которые переносятся из оригинала. Поскольку эта статья датируется апрелем 2003 года, она содержит некоторые нестандартные (не.NET) соглашения о кодировании. Я провел базовое тестирование, а также проблемы сбора мусора, освобождение неуправляемых ресурсов и другие проблемы с очисткой. Поэтому я настоятельно рекомендую избегать кода в этой статье. Более того, код структурирован, так что это затрудняет техническое обслуживание.

Существует чистая упрощенная версия MSDN от июля 2005 года под названием Microsoft Office Thumbnails в SharePoint по адресу http://msdn.microsoft.com/en-us/library/aa289172(VS.71).aspx . Этот код и код статьи имеют сходство, что заставляет меня думать, что извлечение эскизов с использованием статьи оболочки является основой для статьи SharePoint . Версия GetThumbnailImage версии VB.NET игнорирует параметр longestEdge , но версия C ++ использует его и документирует использование ORIGSIZE и QUALITY . Кроме того, код иллюстрирует использование .NET FreeCoTaskMem вместо FreeCoTaskMem Shell и SHGetMalloc .

IExtractImage работает с файлами, папками и другими объектами пространства имен. Код MSDN работает со скрытыми файлами, тогда как для кода vbAccelerator необходимо добавить EnumObjects вызов EnumObjects . Кроме того, vbAccelerator перечисляет объекты оболочки, которые ищут указанный файл, что кажется пустой тратой времени. Возможно, это было необходимо для поиска правильного «относительного» PIDL, который используется для вызова GetUIObjectOf .

ShellThumbnail (Незавершенное производство)

Полный образец проекта по адресу http://cid-7178d2c79ba0a7e3.office.live.com/self.aspx/.Public/ShellThumbnail.zip .

 Imports System.Runtime.InteropServices Namespace Shell ''' 
 ''' Generates a thumbnail of a folder's picture or a file's image. ''' 
 ''' This is the "Folder's Picture" and not the "Folder's Icon"! Use SHGetFileInfo to generate the thumbnail for a folder's icon or for a file that does not have a thumbnail handler. ''' Microsoft Office Thumbnails in SharePoint at http://msdn.microsoft.com/en-us/library/aa289172%28VS.71%29.aspx. Public Class ShellThumbnail 'TODO - Work out the details for image size and IEIFLAG handling. #Region " Determining Thumbnail Size and Quality [documentation] " 'http://support.microsoft.com/kb/835823 'Determining Thumbnail Size and Quality 'Browse to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer. Create or modify two DWORDs called ThumbnailSize and ThumbnailQuality. For ThumbnailSize set the value in pixels, with the default being 96. For ThumbnailQuality set the value as a number that represents the percentage quality between 50 and 100. 'http://www.pctools.com/guides/registry/detail/1066/ (modified) ' User Key: [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer] 'System Key: [HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Explorer] 'Value Name: ThumbnailSize, ThumbnailQuality ' Data Type: REG_DWORD (DWORD Value) 'Value Data: Size in pixels (32-255), Quality Percentage (50-100) 'Microsoft® Windows® XP Registry Guide 'Jerry Honeycutt '09/11/2002 'Microsoft Press 'http://www.microsoft.com/mspress/books/sampchap/6232.aspx#118 '
Thumbnails
The Thumbnails category controls the 'quality of thumbnails in Windows Explorer. Table 5-10 describes the values for 'Image Quality and Size. Create values that you don't see in the registry. The 'default value for ThumbnailQuality is 0x5A. The 'default value for ThumbnailSize is 0x60. Keep in mind 'that higher quality and larger thumbnails require more disk space, which is not 'usually a problem, but they also take longer to display. Changing the quality 'does not affect thumbnails that already exist on the file system. '
Table 5-10 Values in Thumbnails '
 '
 ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' '
Setting
Name
Type
Data
HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer
 
 
 
Image Quality
ThumbnailQuality
REG_DWORD
0x32 - 0x64
Size (pixels)
ThumbnailSize
REG_DWORD
0x20 - 0xFF
 #End Region Public Shared ReadOnly DefaultThumbnailSize As New System.Drawing.Size(96, 96) Public Const DefaultColorDepth As Integer = 32 ''' 
 ''' Used to request an image from an object, such as an item in a Shell folder. ''' 
 ''' An absolute path to a file or folder. Public Shared Function ExtractImage(ByVal path As String) As Bitmap Return ExtractImage(path, System.Drawing.Size.Empty, DefaultColorDepth, 0) End Function ''' 
 ''' Used to request an image from an object, such as an item in a Shell folder. ''' 
 ''' An absolute path to a file or folder. '''  Public Shared Function ExtractImage(ByVal path As String, ByVal size As System.Drawing.Size) As Bitmap Return ExtractImage(path, size, DefaultColorDepth, 0) End Function ''' 
 ''' Used to request an image from an object, such as an item in a Shell folder. ''' 
 ''' An absolute path to a file or folder. '''  ''' The recommended color depth in units of bits per pixel. The default is 32. Public Shared Function ExtractImage(ByVal path As String, ByVal size As System.Drawing.Size, ByVal recommendedColorDepth As Integer) As Bitmap Return ExtractImage(path, size, recommendedColorDepth, 0) End Function ''' 
 ''' Used to request an image from an object, such as an item in a Shell folder. ''' 
 ''' An absolute path to a file or folder. '''  ''' The recommended color depth in units of bits per pixel. The default is 32. Private Shared Function ExtractImage(ByVal path As String, ByVal size As System.Drawing.Size, ByVal recommendedColorDepth As Integer, ByVal flags As IEIFLAG) As Bitmap Dim oResult As Bitmap = Nothing Dim oDesktopFolder As IShellFolder = Nothing Dim hParentIDL As IntPtr Dim hIDL As IntPtr Dim oParentFolder As IShellFolder Dim hParentFolder As IntPtr Dim oExtractImage As IExtractImage Dim hExtractImage As IntPtr 'Divide the file name into a path and file/folder name. Dim sFolderName As String = System.IO.Path.GetDirectoryName(path) Dim sBaseName As String = System.IO.Path.GetFileName(path) 'Get the desktop IShellFolder. If SHGetDesktopFolder(oDesktopFolder) <> Missico.Win32.S_OK Then Throw New System.Runtime.InteropServices.COMException End If 'Get the parent folder for the specified path. oDesktopFolder.ParseDisplayName(IntPtr.Zero, IntPtr.Zero, sFolderName, 0, hParentIDL, 0) oDesktopFolder.BindToObject(hParentIDL, IntPtr.Zero, ShellGUIDs.IID_IShellFolder, hParentFolder) oParentFolder = CType(Marshal.GetTypedObjectForIUnknown(hParentFolder, GetType(IShellFolder)), IShellFolder) 'Get the file/folder's IExtractImage oParentFolder.ParseDisplayName(IntPtr.Zero, IntPtr.Zero, sBaseName, 0, hIDL, 0) oParentFolder.GetUIObjectOf(IntPtr.Zero, 1, New IntPtr() {hIDL}, ShellGUIDs.IID_IExtractImage, IntPtr.Zero, hExtractImage) 'Free the pidls. The Runtime Callable Wrappers (RCW) should automatically release the COM objects. Marshal.FreeCoTaskMem(hParentIDL) Marshal.FreeCoTaskMem(hIDL) Marshal.FinalReleaseComObject(oParentFolder) Marshal.FinalReleaseComObject(oDesktopFolder) If hExtractImage = IntPtr.Zero Then 'There is no handler for this file, which is odd. I believe we should default the file's type icon. Debug.WriteLine(String.Format("There is no thumbnail for the specified file '{0}'.", path), "ShellThumbnail.ExtractImage") Else oExtractImage = CType(Marshal.GetTypedObjectForIUnknown(hExtractImage, GetType(IExtractImage)), IExtractImage) 'Set the size and flags Dim oSize As Missico.Win32.SIZE 'must specify a size Dim iFlags As IEIFLAG = flags Or IEIFLAG.IEIFLAG_ORIGSIZE Or IEIFLAG.IEIFLAG_QUALITY Or IEIFLAG.IEIFLAG_ASPECT If size.IsEmpty Then oSize.cx = DefaultThumbnailSize.Width oSize.cy = DefaultThumbnailSize.Height Else oSize.cx = size.Width oSize.cy = size.Height End If Dim hBitmap As IntPtr Dim sPath As New System.Text.StringBuilder(Missico.Win32.MAX_PATH, Missico.Win32.MAX_PATH) oExtractImage.GetLocation(sPath, sPath.Capacity, 0, oSize, recommendedColorDepth, iFlags) 'if the specified path is to a folder then IExtractImage.Extract fails. Try oExtractImage.Extract(hBitmap) Catch ex As System.Runtime.InteropServices.COMException 'clear the handle since extract failed hBitmap = IntPtr.Zero Debug.WriteLine(String.Format("There is no thumbnail for the specified folder '{0}'.", path), "ShellThumbnail.ExtractImage") Finally Marshal.FinalReleaseComObject(oExtractImage) End Try If Not hBitmap.Equals(IntPtr.Zero) Then 'create the image from the handle oResult = System.Drawing.Bitmap.FromHbitmap(hBitmap) 'dump the properties to determine what kind of bitmap is returned 'Missico.Diagnostics.ObjectDumper.Write(oResult) 'Tag={ } 'PhysicalDimension={Width=96, Height=96} 'Size={Width=96, Height=96} 'Width=96 'Height=96 'HorizontalResolution=96 'VerticalResolution=96 'Flags=335888 'RawFormat={ } 'PixelFormat=Format32bppRgb 'Palette={ } 'FrameDimensionsList=... 'PropertyIdList=... 'PropertyItems=... Missico.Win32.DeleteObject(hBitmap) 'release the handle End If End If Return oResult End Function End Class End Namespace , Imports System.Runtime.InteropServices Namespace Shell ''' 
 ''' Generates a thumbnail of a folder's picture or a file's image. ''' 
 ''' This is the "Folder's Picture" and not the "Folder's Icon"! Use SHGetFileInfo to generate the thumbnail for a folder's icon or for a file that does not have a thumbnail handler. ''' Microsoft Office Thumbnails in SharePoint at http://msdn.microsoft.com/en-us/library/aa289172%28VS.71%29.aspx. Public Class ShellThumbnail 'TODO - Work out the details for image size and IEIFLAG handling. #Region " Determining Thumbnail Size and Quality [documentation] " 'http://support.microsoft.com/kb/835823 'Determining Thumbnail Size and Quality 'Browse to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer. Create or modify two DWORDs called ThumbnailSize and ThumbnailQuality. For ThumbnailSize set the value in pixels, with the default being 96. For ThumbnailQuality set the value as a number that represents the percentage quality between 50 and 100. 'http://www.pctools.com/guides/registry/detail/1066/ (modified) ' User Key: [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer] 'System Key: [HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Explorer] 'Value Name: ThumbnailSize, ThumbnailQuality ' Data Type: REG_DWORD (DWORD Value) 'Value Data: Size in pixels (32-255), Quality Percentage (50-100) 'Microsoft® Windows® XP Registry Guide 'Jerry Honeycutt '09/11/2002 'Microsoft Press 'http://www.microsoft.com/mspress/books/sampchap/6232.aspx#118 '
Thumbnails
The Thumbnails category controls the 'quality of thumbnails in Windows Explorer. Table 5-10 describes the values for 'Image Quality and Size. Create values that you don't see in the registry. The 'default value for ThumbnailQuality is 0x5A. The 'default value for ThumbnailSize is 0x60. Keep in mind 'that higher quality and larger thumbnails require more disk space, which is not 'usually a problem, but they also take longer to display. Changing the quality 'does not affect thumbnails that already exist on the file system. '
Table 5-10 Values in Thumbnails '
 '
 ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' '
Setting
Name
Type
Data
HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer
 
 
 
Image Quality
ThumbnailQuality
REG_DWORD
0x32 - 0x64
Size (pixels)
ThumbnailSize
REG_DWORD
0x20 - 0xFF
 #End Region Public Shared ReadOnly DefaultThumbnailSize As New System.Drawing.Size(96, 96) Public Const DefaultColorDepth As Integer = 32 ''' 
 ''' Used to request an image from an object, such as an item in a Shell folder. ''' 
 ''' An absolute path to a file or folder. Public Shared Function ExtractImage(ByVal path As String) As Bitmap Return ExtractImage(path, System.Drawing.Size.Empty, DefaultColorDepth, 0) End Function ''' 
 ''' Used to request an image from an object, such as an item in a Shell folder. ''' 
 ''' An absolute path to a file or folder. '''  Public Shared Function ExtractImage(ByVal path As String, ByVal size As System.Drawing.Size) As Bitmap Return ExtractImage(path, size, DefaultColorDepth, 0) End Function ''' 
 ''' Used to request an image from an object, such as an item in a Shell folder. ''' 
 ''' An absolute path to a file or folder. '''  ''' The recommended color depth in units of bits per pixel. The default is 32. Public Shared Function ExtractImage(ByVal path As String, ByVal size As System.Drawing.Size, ByVal recommendedColorDepth As Integer) As Bitmap Return ExtractImage(path, size, recommendedColorDepth, 0) End Function ''' 
 ''' Used to request an image from an object, such as an item in a Shell folder. ''' 
 ''' An absolute path to a file or folder. '''  ''' The recommended color depth in units of bits per pixel. The default is 32. Private Shared Function ExtractImage(ByVal path As String, ByVal size As System.Drawing.Size, ByVal recommendedColorDepth As Integer, ByVal flags As IEIFLAG) As Bitmap Dim oResult As Bitmap = Nothing Dim oDesktopFolder As IShellFolder = Nothing Dim hParentIDL As IntPtr Dim hIDL As IntPtr Dim oParentFolder As IShellFolder Dim hParentFolder As IntPtr Dim oExtractImage As IExtractImage Dim hExtractImage As IntPtr 'Divide the file name into a path and file/folder name. Dim sFolderName As String = System.IO.Path.GetDirectoryName(path) Dim sBaseName As String = System.IO.Path.GetFileName(path) 'Get the desktop IShellFolder. If SHGetDesktopFolder(oDesktopFolder) <> Missico.Win32.S_OK Then Throw New System.Runtime.InteropServices.COMException End If 'Get the parent folder for the specified path. oDesktopFolder.ParseDisplayName(IntPtr.Zero, IntPtr.Zero, sFolderName, 0, hParentIDL, 0) oDesktopFolder.BindToObject(hParentIDL, IntPtr.Zero, ShellGUIDs.IID_IShellFolder, hParentFolder) oParentFolder = CType(Marshal.GetTypedObjectForIUnknown(hParentFolder, GetType(IShellFolder)), IShellFolder) 'Get the file/folder's IExtractImage oParentFolder.ParseDisplayName(IntPtr.Zero, IntPtr.Zero, sBaseName, 0, hIDL, 0) oParentFolder.GetUIObjectOf(IntPtr.Zero, 1, New IntPtr() {hIDL}, ShellGUIDs.IID_IExtractImage, IntPtr.Zero, hExtractImage) 'Free the pidls. The Runtime Callable Wrappers (RCW) should automatically release the COM objects. Marshal.FreeCoTaskMem(hParentIDL) Marshal.FreeCoTaskMem(hIDL) Marshal.FinalReleaseComObject(oParentFolder) Marshal.FinalReleaseComObject(oDesktopFolder) If hExtractImage = IntPtr.Zero Then 'There is no handler for this file, which is odd. I believe we should default the file's type icon. Debug.WriteLine(String.Format("There is no thumbnail for the specified file '{0}'.", path), "ShellThumbnail.ExtractImage") Else oExtractImage = CType(Marshal.GetTypedObjectForIUnknown(hExtractImage, GetType(IExtractImage)), IExtractImage) 'Set the size and flags Dim oSize As Missico.Win32.SIZE 'must specify a size Dim iFlags As IEIFLAG = flags Or IEIFLAG.IEIFLAG_ORIGSIZE Or IEIFLAG.IEIFLAG_QUALITY Or IEIFLAG.IEIFLAG_ASPECT If size.IsEmpty Then oSize.cx = DefaultThumbnailSize.Width oSize.cy = DefaultThumbnailSize.Height Else oSize.cx = size.Width oSize.cy = size.Height End If Dim hBitmap As IntPtr Dim sPath As New System.Text.StringBuilder(Missico.Win32.MAX_PATH, Missico.Win32.MAX_PATH) oExtractImage.GetLocation(sPath, sPath.Capacity, 0, oSize, recommendedColorDepth, iFlags) 'if the specified path is to a folder then IExtractImage.Extract fails. Try oExtractImage.Extract(hBitmap) Catch ex As System.Runtime.InteropServices.COMException 'clear the handle since extract failed hBitmap = IntPtr.Zero Debug.WriteLine(String.Format("There is no thumbnail for the specified folder '{0}'.", path), "ShellThumbnail.ExtractImage") Finally Marshal.FinalReleaseComObject(oExtractImage) End Try If Not hBitmap.Equals(IntPtr.Zero) Then 'create the image from the handle oResult = System.Drawing.Bitmap.FromHbitmap(hBitmap) 'dump the properties to determine what kind of bitmap is returned 'Missico.Diagnostics.ObjectDumper.Write(oResult) 'Tag={ } 'PhysicalDimension={Width=96, Height=96} 'Size={Width=96, Height=96} 'Width=96 'Height=96 'HorizontalResolution=96 'VerticalResolution=96 'Flags=335888 'RawFormat={ } 'PixelFormat=Format32bppRgb 'Palette={ } 'FrameDimensionsList=... 'PropertyIdList=... 'PropertyItems=... Missico.Win32.DeleteObject(hBitmap) 'release the handle End If End If Return oResult End Function End Class End Namespace 

Это может помочь:

http://blogs.msdn.com/windowssdk/archive/2009/06/12/windows-api-code-pack-for-microsoft-net-framework.aspx

Это включает в себя Shell API и позволяет делать практически все, что может использовать shell (включая рендеринг эскизов).

Вот class, который я нашел в Интернете. Похоже, что исходный код получен из http://www.experts-exchange.com/Programming/Languages/C_Sharp/Q_21789724.html , но я не вижу его, чтобы дать правильную атрибуцию. Я нашел источник здесь: http://www.vbforums.com/showthread.php?t=527704

Вот class с соответствующими COM-вызовами, воспроизведенными здесь для потомков:

 using System; using System.Diagnostics; using System.Drawing; using System.IO; using System.Runtime.InteropServices; using System.Text; namespace RMA.Shell { public class ShellThumbnail : IDisposable { [Flags] private enum ESTRRET { STRRET_WSTR = 0, STRRET_OFFSET = 1, STRRET_CSTR = 2 } [Flags] private enum ESHCONTF { SHCONTF_FOLDERS = 32, SHCONTF_NONFOLDERS = 64, SHCONTF_INCLUDEHIDDEN = 128, } [Flags] private enum ESHGDN { SHGDN_NORMAL = 0, SHGDN_INFOLDER = 1, SHGDN_FORADDRESSBAR = 16384, SHGDN_FORPARSING = 32768 } [Flags] private enum ESFGAO { SFGAO_CANCOPY = 1, SFGAO_CANMOVE = 2, SFGAO_CANLINK = 4, SFGAO_CANRENAME = 16, SFGAO_CANDELETE = 32, SFGAO_HASPROPSHEET = 64, SFGAO_DROPTARGET = 256, SFGAO_CAPABILITYMASK = 375, SFGAO_LINK = 65536, SFGAO_SHARE = 131072, SFGAO_READONLY = 262144, SFGAO_GHOSTED = 524288, SFGAO_DISPLAYATTRMASK = 983040, SFGAO_FILESYSANCESTOR = 268435456, SFGAO_FOLDER = 536870912, SFGAO_FILESYSTEM = 1073741824, SFGAO_HASSUBFOLDER = -2147483648, SFGAO_CONTENTSMASK = -2147483648, SFGAO_VALIDATE = 16777216, SFGAO_REMOVABLE = 33554432, SFGAO_COMPRESSED = 67108864, } private enum EIEIFLAG { IEIFLAG_ASYNC = 1, IEIFLAG_CACHE = 2, IEIFLAG_ASPECT = 4, IEIFLAG_OFFLINE = 8, IEIFLAG_GLEAM = 16, IEIFLAG_SCREEN = 32, IEIFLAG_ORIGSIZE = 64, IEIFLAG_NOSTAMP = 128, IEIFLAG_NOBORDER = 256, IEIFLAG_QUALITY = 512 } [StructLayout(LayoutKind.Sequential, Pack = 4, Size = 0, CharSet = CharSet.Auto)] private struct STRRET_CSTR { public ESTRRET uType; [MarshalAs(UnmanagedType.ByValArray, SizeConst = 520)] public byte[] cStr; } [StructLayout(LayoutKind.Explicit, CharSet = CharSet.Auto)] private struct STRRET_ANY { [FieldOffset(0)] public ESTRRET uType; [FieldOffset(4)] public IntPtr pOLEString; } [StructLayoutAttribute(LayoutKind.Sequential)] private struct SIZE { public int cx; public int cy; } [ComImport(), Guid("00000000-0000-0000-C000-000000000046")] [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)] private interface IUnknown { [PreserveSig()] IntPtr QueryInterface(ref Guid riid, ref IntPtr pVoid); [PreserveSig()] IntPtr AddRef(); [PreserveSig()] IntPtr Release(); } [ComImportAttribute()] [GuidAttribute("00000002-0000-0000-C000-000000000046")] [InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)] private interface IMalloc { [PreserveSig()] IntPtr Alloc(int cb); [PreserveSig()] IntPtr Realloc(IntPtr pv, int cb); [PreserveSig()] void Free(IntPtr pv); [PreserveSig()] int GetSize(IntPtr pv); [PreserveSig()] int DidAlloc(IntPtr pv); [PreserveSig()] void HeapMinimize(); } [ComImportAttribute()] [GuidAttribute("000214F2-0000-0000-C000-000000000046")] [InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)] private interface IEnumIDList { [PreserveSig()] int Next(int celt, ref IntPtr rgelt, ref int pceltFetched); void Skip(int celt); void Reset(); void Clone(ref IEnumIDList ppenum); } [ComImportAttribute()] [GuidAttribute("000214E6-0000-0000-C000-000000000046")] [InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)] private interface IShellFolder { void ParseDisplayName(IntPtr hwndOwner, IntPtr pbcReserved, [MarshalAs(UnmanagedType.LPWStr)]string lpszDisplayName, ref int pchEaten, ref IntPtr ppidl, ref int pdwAttributes); void EnumObjects(IntPtr hwndOwner, [MarshalAs(UnmanagedType.U4)]ESHCONTF grfFlags, ref IEnumIDList ppenumIDList); void BindToObject(IntPtr pidl, IntPtr pbcReserved, ref Guid riid, ref IShellFolder ppvOut); void BindToStorage(IntPtr pidl, IntPtr pbcReserved, ref Guid riid, IntPtr ppvObj); [PreserveSig()] int CompareIDs(IntPtr lParam, IntPtr pidl1, IntPtr pidl2); void CreateViewObject(IntPtr hwndOwner, ref Guid riid, IntPtr ppvOut); void GetAttributesOf(int cidl, IntPtr apidl, [MarshalAs(UnmanagedType.U4)]ref ESFGAO rgfInOut); void GetUIObjectOf(IntPtr hwndOwner, int cidl, ref IntPtr apidl, ref Guid riid, ref int prgfInOut, ref IUnknown ppvOut); void GetDisplayNameOf(IntPtr pidl, [MarshalAs(UnmanagedType.U4)]ESHGDN uFlags, ref STRRET_CSTR lpName); void SetNameOf(IntPtr hwndOwner, IntPtr pidl, [MarshalAs(UnmanagedType.LPWStr)]string lpszName, [MarshalAs(UnmanagedType.U4)] ESHCONTF uFlags, ref IntPtr ppidlOut); } [ComImportAttribute(), GuidAttribute("BB2E617C-0920-11d1-9A0B-00C04FC2D6C1"), InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)] private interface IExtractImage { void GetLocation([Out(), MarshalAs(UnmanagedType.LPWStr)] StringBuilder pszPathBuffer, int cch, ref int pdwPriority, ref SIZE prgSize, int dwRecClrDepth, ref int pdwFlags); void Extract(ref IntPtr phBmpThumbnail); } private class UnmanagedMethods { [DllImport("shell32", CharSet = CharSet.Auto)] internal extern static int SHGetMalloc(ref IMalloc ppMalloc); [DllImport("shell32", CharSet = CharSet.Auto)] internal extern static int SHGetDesktopFolder(ref IShellFolder ppshf); [DllImport("shell32", CharSet = CharSet.Auto)] internal extern static int SHGetPathFromIDList(IntPtr pidl, StringBuilder pszPath); [DllImport("gdi32", CharSet = CharSet.Auto)] internal extern static int DeleteObject(IntPtr hObject); } ~ShellThumbnail() { Dispose(); } private IMalloc alloc = null; private bool disposed = false; private Size _desiredSize = new Size(100, 100); private Bitmap _thumbNail; public Bitmap ThumbNail { get { return _thumbNail; } } public Size DesiredSize { get { return _desiredSize; } set { _desiredSize = value; } } private IMalloc Allocator { get { if (!disposed) { if (alloc == null) { UnmanagedMethods.SHGetMalloc(ref alloc); } } else { Debug.Assert(false, "Object has been disposed."); } return alloc; } } public Bitmap GetThumbnail(string fileName) { if (string.IsNullOrEmpty(fileName)) return null; if (!File.Exists(fileName) && !Directory.Exists(fileName)) { throw new FileNotFoundException(string.Format("The file '{0}' does not exist", fileName), fileName); } if (_thumbNail != null) { _thumbNail.Dispose(); _thumbNail = null; } IShellFolder folder = null; try { folder = getDesktopFolder; } catch (Exception ex) { throw ex; } if (folder != null) { IntPtr pidlMain = IntPtr.Zero; try { int cParsed = 0; int pdwAttrib = 0; string filePath = Path.GetDirectoryName(fileName); folder.ParseDisplayName(IntPtr.Zero, IntPtr.Zero, filePath, ref cParsed, ref pidlMain, ref pdwAttrib); } catch (Exception ex) { Marshal.ReleaseComObject(folder); throw ex; } if (pidlMain != IntPtr.Zero) { Guid iidShellFolder = new Guid("000214E6-0000-0000-C000-000000000046"); IShellFolder item = null; try { folder.BindToObject(pidlMain, IntPtr.Zero, ref iidShellFolder, ref item); } catch (Exception ex) { Marshal.ReleaseComObject(folder); Allocator.Free(pidlMain); throw ex; } if (item != null) { IEnumIDList idEnum = null; try { item.EnumObjects(IntPtr.Zero, (ESHCONTF.SHCONTF_FOLDERS | ESHCONTF.SHCONTF_NONFOLDERS), ref idEnum); } catch (Exception ex) { Marshal.ReleaseComObject(folder); Allocator.Free(pidlMain); throw ex; } if (idEnum != null) { int hRes = 0; IntPtr pidl = IntPtr.Zero; int fetched = 0; bool complete = false; while (!complete) { hRes = idEnum.Next(1, ref pidl, ref fetched); if (hRes != 0) { pidl = IntPtr.Zero; complete = true; } else { if (_getThumbNail(fileName, pidl, item)) { complete = true; } } if (pidl != IntPtr.Zero) { Allocator.Free(pidl); } } Marshal.ReleaseComObject(idEnum); } Marshal.ReleaseComObject(item); } Allocator.Free(pidlMain); } Marshal.ReleaseComObject(folder); } return ThumbNail; } private bool _getThumbNail(string file, IntPtr pidl, IShellFolder item) { IntPtr hBmp = IntPtr.Zero; IExtractImage extractImage = null; try { string pidlPath = PathFromPidl(pidl); if (Path.GetFileName(pidlPath).ToUpper().Equals(Path.GetFileName(file).ToUpper())) { IUnknown iunk = null; int prgf = 0; Guid iidExtractImage = new Guid("BB2E617C-0920-11d1-9A0B-00C04FC2D6C1"); item.GetUIObjectOf(IntPtr.Zero, 1, ref pidl, ref iidExtractImage, ref prgf, ref iunk); extractImage = (IExtractImage)iunk; if (extractImage != null) { Console.WriteLine("Got an IExtractImage object!"); SIZE sz = new SIZE(); sz.cx = DesiredSize.Width; sz.cy = DesiredSize.Height; StringBuilder location = new StringBuilder(260, 260); int priority = 0; int requestedColourDepth = 32; EIEIFLAG flags = EIEIFLAG.IEIFLAG_ASPECT | EIEIFLAG.IEIFLAG_SCREEN; int uFlags = (int)flags; try { extractImage.GetLocation(location, location.Capacity, ref priority, ref sz, requestedColourDepth, ref uFlags); extractImage.Extract(ref hBmp); } catch (System.Runtime.InteropServices.COMException ex) { } if (hBmp != IntPtr.Zero) { _thumbNail = Bitmap.FromHbitmap(hBmp); } Marshal.ReleaseComObject(extractImage); extractImage = null; } return true; } else { return false; } } catch (Exception ex) { if (hBmp != IntPtr.Zero) { UnmanagedMethods.DeleteObject(hBmp); } if (extractImage != null) { Marshal.ReleaseComObject(extractImage); } throw ex; } } private string PathFromPidl(IntPtr pidl) { StringBuilder path = new StringBuilder(260, 260); int result = UnmanagedMethods.SHGetPathFromIDList(pidl, path); if (result == 0) { return string.Empty; } else { return path.ToString(); } } private IShellFolder getDesktopFolder { get { IShellFolder ppshf = null; int r = UnmanagedMethods.SHGetDesktopFolder(ref ppshf); return ppshf; } } public void Dispose() { if (!disposed) { if (alloc != null) { Marshal.ReleaseComObject(alloc); } alloc = null; if (_thumbNail != null) { _thumbNail.Dispose(); } disposed = true; } } } } 

К сожалению, к сожалению, к ним не относятся мини-эскизы окон API-интерфейса Windows API.

Не совсем то, что вы просили, но вот проект для открытия файла Thumbs.db .
Статья в Википедии содержит дополнительную информацию о том, где найти миниатюры в Vista & 7.

Вы должны использовать windows GDI + для получения этих миниатюр, например.