c# - 您可以从系统中获取默认文件夹的打开/关闭图标而没有实际路径吗？

Question

我已经知道如何通过P/调用SHGetFileInfo来获取特定路径的文件系统相关图标。但这需要一条实际的道路。另外，它仅返回一个图标。

我想知道的是两方面的。

如何获得默认文件夹的打开和关闭图标(我相信它们存储在“C:\WINDOWS\system32\imageres.dll”或“％SystemRoot％\system32\shell32.dll”中，但我可能错了)

如何在不实际指定路径的情况下(即通过常量或类似名称)获取那些图标。

甚至有这种方法，还是我必须简单地将它传递给SHGetFileInfo的“虚拟”路径，而忘记拥有两种状态？

作为引用，我正在寻找它，因为我们正在构建一个自定义树来显示某些文件系统对象，但是它们将显示在几个应用程序定义的组下面，并且我们希望这些组类似于用于以下操作的图形文件夹实际目录。

Answer 1

是的你可以。

Disclaimer (TL,DR) :
Don't get mad at me for the length of this answer. 98% of it is just plain enumeration code you only have to copy paste (I just like having everything at the same place and time)

请注意，众所周知System.Drawing命名空间中的图标操作容易导致 内存泄漏。我不明白为什么多年来 DestroyIcon(handle)的使用没有做过任何改变(这也会使您的图标缩小为零尺寸的0x0图标)，而您应该在代码的其他地方使用该图标。 ..

... Plus, it only returns a single icon...

据我所知，没有一个托管或非托管方法会返回具有多个单一格式和大小的图标。要使用不同的图标，您必须一个一个地调用它们，或者通过解析包含图标变体的文件来创建每个图标。

顺便说一下，我只是一个业余程序员，碰巧发现了揭穿整个Icon困惑的方法。我在这里写的是初学者水平。随时纠正我犯的任何错误(我敢肯定有)。我只是惊讶地发现了涉及图标的UI任务的答案有多么困难。

看看 PInvoke/SHGetStockIconInfo

基本上，您必须:

创建SHSTOCKICONID结构

初始化大小

使用此结构，文件夹图标ID(枚举成员)和图标选项

调用 SHGetStockIconInfo(...)

您会在系统的常用图标(包括文件夹图标)中找到您要寻找的图标的指针。

顺便说一句，该方法还可以通过结构(如果正确初始化的话)为您提供有用的信息，例如包含系统图标的文件的路径以及该文件在该文件中的索引，但是由于您已经有了指向该图标的指针，您所要做的就是创建一个图标:

Icon icon = Icon.FromHandle(handle)
// And here is where you don't really know how to destroy the handle...

CAUTION !!!
The API and some enum values doesn't work on some platforms. Simply put, everything before Windows Vista has little to no support at all. Furthermore, almost everything is for Desktop Applications only ! By the way, things may not work on Windows CE.

Windows 7 and above has extended capabilities that are not covered by this answer.

Known alternative to API calls : WPF and VectorIcons. Not covered here.

使用以下命名空间:

using System.Runtime.InteropServices; // [DllImport()], [MarshalAs()]
using System.Runtime.CompilerServices // [Extension()]

首先要声明的很重要: DestroyIcon() 方法。

/// <summary>
/// Destroys an icon and frees any memory the icon occupied.
/// </summary>
/// <param name="hIcon">A handle to the icon to be destroyed. The icon must not be in use.</param>
/// <returns>If the function succeeds, the return value is nonzero. If the function fails, the return value is zero.</returns>
/// <remarks>To get extended error information, call GetLastError.</remarks>
[DllImport("user32.dll", EntryPoint = "DestroyIcon", SetLastError = true)]
private static extern bool DestroyIcon(IntPtr hIcon);

因此，这是您的 Shell32声明(由PInvoke提供，添加了XML注释):

/// <summary>
/// Retrieves information about a stock icon.
/// </summary>
/// <param name="siid">One of the values from the SHSTOCKICONID enumeration that specifies which icon should be retrieved.</param>
/// <param name="uFlags">A combination of zero or more of the following flags that specify which information is requested.</param>
/// <param name="psii">A pointer to a SHSTOCKICONINFO structure. When this function is called, the cbSize member of this structure needs to be set to the size of the SHSTOCKICONINFO structure. When this function returns, contains a pointer to a SHSTOCKICONINFO structure that contains the requested information.</param>
/// <returns>If this function succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.</returns>
/// <remarks>If this function returns an icon handle in the hIcon member of the SHSTOCKICONINFO structure pointed to by psii, you are responsible for freeing the icon with DestroyIcon when you no longer need it.</remarks>
[DllImport("Shell32.dll", SetLastError = false)]
private static extern Int32 SHGetStockIconInfo(SHSTOCKICONID siid, SHGSI uFlags, ref SHSTOCKICONINFO psii);

这是 SHSTOCKICONINFO结构的样子(添加了XML注释):

/// <summary>
/// Receives information used to retrieve a stock Shell icon. This structure is used in a call SHGetStockIconInfo.
/// </summary>
[StructLayoutAttribute(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct SHSTOCKICONINFO
{
    /// <summary>
    /// The size of this structure, in bytes.
    /// </summary>
    public UInt32 cbSize;
    /// <summary>
    /// When SHGetStockIconInfo is called with the SHGSI_ICON flag, this member receives a handle to the icon.
    /// </summary>
    public IntPtr hIcon;
    /// <summary>
    /// When SHGetStockIconInfo is called with the SHGSI_SYSICONINDEX flag, this member receives the index of the image in the system icon cache.
    /// </summary>
    public Int32 iSysIconIndex;
    /// <summary>
    /// When SHGetStockIconInfo is called with the SHGSI_ICONLOCATION flag, this member receives the index of the icon in the resource whose path is received in szPath.
    /// </summary>
    public Int32 iIcon;
    /// <summary>
    /// When SHGetStockIconInfo is called with the SHGSI_ICONLOCATION flag, this member receives the path of the resource that contains the icon. The index of the icon within the resource is received in iIcon.
    /// </summary>
    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = MAX_PATH)]
    public string szPath;
}

因为未定义 MAX_PATH结构中的 SHSTOCKICONINFO ，所以它是:

const Int32 MAX_PATH = 260;

SHGSI 是一个枚举，用于定义要与调用 SHGetStockIconInfo()一起提交的选项

/// <summary>
/// UInt Enumeration with Flags that specify which information is requested.
/// </summary>
[Flags()]
public enum SHGSI : UInt32
{

    /// <summary>
    /// The szPath and iIcon members of the SHSTOCKICONINFO structure receive the path and icon index of the requested icon, in a format suitable for passing to the ExtractIcon function. The numerical value of this flag is zero, so you always get the icon location regardless of other flags.
    /// </summary>
    SHGSI_ICONLOCATION = 0,

    /// <summary>
    /// The hIcon member of the SHSTOCKICONINFO structure receives a handle to the specified icon.
    /// </summary>
    SHGSI_ICON = 0x100,

    /// <summary>
    /// The iSysImageImage member of the SHSTOCKICONINFO structure receives the index of the specified icon in the system imagelist.
    /// </summary>
    SHGSI_SYSICONINDEX = 0x4000,

    /// <summary>
    /// Modifies the SHGSI_ICON value by causing the function to add the link overlay to the file's icon.
    /// </summary>
    SHGSI_LINKOVERLAY = 0x8000,

    /// <summary>
    /// Modifies the SHGSI_ICON value by causing the function to blend the icon with the system highlight color.
    /// </summary>
    SHGSI_SELECTED = 0x10000,

    /// <summary>
    /// Modifies the SHGSI_ICON value by causing the function to retrieve the large version of the icon, as specified by the SM_CXICON and SM_CYICON system metrics.
    /// </summary>
    SHGSI_LARGEICON = 0x0,

    /// <summary>
    /// Modifies the SHGSI_ICON value by causing the function to retrieve the small version of the icon, as specified by the SM_CXSMICON and SM_CYSMICON system metrics.
    /// </summary>
    SHGSI_SMALLICON = 0x1,

    /// <summary>
    /// Modifies the SHGSI_LARGEICON or SHGSI_SMALLICON values by causing the function to retrieve the Shell-sized icons rather than the sizes specified by the system metrics.
    /// </summary>
    SHGSI_SHELLICONSIZE = 0x4

}

SHSTOCKICONID是一个包含很多值的枚举。希望您不会有那么头疼...:P-请坐一下这个Enumeration的 MSDN constants，以了解图标的外观。

/// <summary>
/// Used by SHGetStockIconInfo to identify which stock system icon to retrieve.
/// </summary>
/// <remarks>SIID_INVALID, with a value of -1, indicates an invalid SHSTOCKICONID value.</remarks>
public enum SHSTOCKICONID : UInt32
{
    /// <summary>
    /// Document of a type with no associated application.
    /// </summary>
    SIID_DOCNOASSOC = 0,
    /// <summary>
    /// Document of a type with an associated application.
    /// </summary>
    SIID_DOCASSOC = 1,
    /// <summary>
    /// Generic application with no custom icon.
    /// </summary>
    SIID_APPLICATION = 2,
    /// <summary>
    /// Folder (generic, unspecified state).
    /// </summary>
    SIID_FOLDER = 3,
    /// <summary>
    /// Folder (open).
    /// </summary>
    SIID_FOLDEROPEN = 4,
    /// <summary>
    /// 5.25-inch disk drive.
    /// </summary>
    SIID_DRIVE525 = 5,
    /// <summary>
    /// 3.5-inch disk drive.
    /// </summary>
    SIID_DRIVE35 = 6,
    /// <summary>
    /// Removable drive.
    /// </summary>
    SIID_DRIVEREMOVE = 7,
    /// <summary>
    /// Fixed drive (hard disk).
    /// </summary>
    SIID_DRIVEFIXED = 8,
    /// <summary>
    /// Network drive (connected).
    /// </summary>
    SIID_DRIVENET = 9,
    /// <summary>
    /// Network drive (disconnected).
    /// </summary>
    SIID_DRIVENETDISABLED = 10,
    /// <summary>
    /// CD drive.
    /// </summary>
    SIID_DRIVECD = 11,
    /// <summary>
    /// RAM disk drive.
    /// </summary>
    SIID_DRIVERAM = 12,
    /// <summary>
    /// The entire network.
    /// </summary>
    SIID_WORLD = 13,
    /// <summary>
    /// A computer on the network.
    /// </summary>
    SIID_SERVER = 15,
    /// <summary>
    /// A local printer or print destination.
    /// </summary>
    SIID_PRINTER = 16,
    /// <summary>
    /// The Network virtual folder (FOLDERID_NetworkFolder/CSIDL_NETWORK).
    /// </summary>
    SIID_MYNETWORK = 17,
    /// <summary>
    /// The Search feature.
    /// </summary>
    SIID_FIND = 22,
    /// <summary>
    /// The Help and Support feature.
    /// </summary>
    SIID_HELP = 23,

// OVERLAYS...

    /// <summary>
    /// Overlay for a shared item.
    /// </summary>
    SIID_SHARE = 28,
    /// <summary>
    /// Overlay for a shortcut.
    /// </summary>
    SIID_LINK = 29,
    /// <summary>
    /// Overlay for items that are expected to be slow to access.
    /// </summary>
    SIID_SLOWFILE = 30,

// MORE ICONS...

    /// <summary>
    /// The Recycle Bin (empty).
    /// </summary>
    SIID_RECYCLER = 31,
    /// <summary>
    /// The Recycle Bin (not empty).
    /// </summary>
    SIID_RECYCLERFULL = 32,
    /// <summary>
    /// Audio CD media.
    /// </summary>
    SIID_MEDIACDAUDIO = 40,
    /// <summary>
    /// Security lock.
    /// </summary>
    SIID_LOCK = 47,
    /// <summary>
    /// A virtual folder that contains the results of a search.
    /// </summary>
    SIID_AUTOLIST = 49,
    /// <summary>
    /// A network printer.
    /// </summary>
    SIID_PRINTERNET = 50,
    /// <summary>
    /// A server shared on a network.
    /// </summary>
    SIID_SERVERSHARE = 51,
    /// <summary>
    /// A local fax printer.
    /// </summary>
    SIID_PRINTERFAX = 52,
    /// <summary>
    /// A network fax printer.
    /// </summary>
    SIID_PRINTERFAXNET = 53,
    /// <summary>
    /// A file that receives the output of a Print to file operation.
    /// </summary>
    SIID_PRINTERFILE = 54,
    /// <summary>
    /// A category that results from a Stack by command to organize the contents of a folder.
    /// </summary>
    SIID_STACK = 55,
    /// <summary>
    /// Super Video CD (SVCD) media.
    /// </summary>
    SIID_MEDIASVCD = 56,
    /// <summary>
    /// A folder that contains only subfolders as child items.
    /// </summary>
    SIID_STUFFEDFOLDER = 57,
    /// <summary>
    /// Unknown drive type.
    /// </summary>
    SIID_DRIVEUNKNOWN = 58,
    /// <summary>
    /// DVD drive.
    /// </summary>
    SIID_DRIVEDVD = 59,
    /// <summary>
    /// DVD media.
    /// </summary>
    SIID_MEDIADVD = 60,
    /// <summary>
    /// DVD-RAM media.
    /// </summary>
    SIID_MEDIADVDRAM = 61,
    /// <summary>
    /// DVD-RW media.
    /// </summary>
    SIID_MEDIADVDRW = 62,
    /// <summary>
    /// DVD-R media.
    /// </summary>
    SIID_MEDIADVDR = 63,
    /// <summary>
    /// DVD-ROM media.
    /// </summary>
    SIID_MEDIADVDROM = 64,
    /// <summary>
    /// CD+ (enhanced audio CD) media.
    /// </summary>
    SIID_MEDIACDAUDIOPLUS = 65,
    /// <summary>
    /// CD-RW media.
    /// </summary>
    SIID_MEDIACDRW = 66,
    /// <summary>
    /// CD-R media.
    /// </summary>
    SIID_MEDIACDR = 67,
    /// <summary>
    /// A writeable CD in the process of being burned.
    /// </summary>
    SIID_MEDIACDBURN = 68,
    /// <summary>
    /// Blank writable CD media.
    /// </summary>
    SIID_MEDIABLANKCD = 69,
    /// <summary>
    /// CD-ROM media.
    /// </summary>
    SIID_MEDIACDROM = 70,
    /// <summary>
    /// An audio file.
    /// </summary>
    SIID_AUDIOFILES = 71,
    /// <summary>
    /// An image file.
    /// </summary>
    SIID_IMAGEFILES = 72,
    /// <summary>
    /// A video file.
    /// </summary>
    SIID_VIDEOFILES = 73,
    /// <summary>
    /// A mixed (media) file.
    /// </summary>
    SIID_MIXEDFILES = 74,


    /// <summary>
    /// Folder back. Represents the background Fold of a Folder.
    /// </summary>
    SIID_FOLDERBACK = 75,
    /// <summary>
    /// Folder front. Represents the foreground Fold of a Folder.
    /// </summary>
    SIID_FOLDERFRONT = 76,
    /// <summary>
    /// Security shield.
    /// </summary>
    /// <remarks>Use for UAC prompts only. This Icon doesn't work on all purposes.</remarks>
    SIID_SHIELD = 77,
    /// <summary>
    /// Warning (Exclamation mark).
    /// </summary>
    SIID_WARNING = 78,
    /// <summary>
    /// Informational (Info).
    /// </summary>
    SIID_INFO = 79,
    /// <summary>
    /// Error (X).
    /// </summary>
    SIID_ERROR = 80,
    /// <summary>
    /// Key.
    /// </summary>
    SIID_KEY = 81,
    /// <summary>
    /// Software.
    /// </summary>
    SIID_SOFTWARE = 82,
    /// <summary>
    /// A UI item, such as a button, that issues a rename command.
    /// </summary>
    SIID_RENAME = 83,
    /// <summary>
    /// A UI item, such as a button, that issues a delete command.
    /// </summary>
    SIID_DELETE = 84,
    /// <summary>
    /// Audio DVD media.
    /// </summary>
    SIID_MEDIAAUDIODVD = 85,
    /// <summary>
    /// Movie DVD media.
    /// </summary>
    SIID_MEDIAMOVIEDVD = 86,
    /// <summary>
    /// Enhanced CD media.
    /// </summary>
    SIID_MEDIAENHANCEDCD = 87,
    /// <summary>
    /// Enhanced DVD media.
    /// </summary>
    SIID_MEDIAENHANCEDDVD = 88,
    /// <summary>
    /// Enhanced DVD media.
    /// </summary>
    SIID_MEDIAHDDVD = 89,
    /// <summary>
    /// High definition DVD media in the Blu-ray Disc™ format.
    /// </summary>
    SIID_MEDIABLURAY = 90,
    /// <summary>
    /// Video CD (VCD) media.
    /// </summary>
    SIID_MEDIAVCD = 91,
    /// <summary>
    /// DVD+R media.
    /// </summary>
    SIID_MEDIADVDPLUSR = 92,
    /// <summary>
    /// DVD+RW media.
    /// </summary>
    SIID_MEDIADVDPLUSRW = 93,
    /// <summary>
    /// A desktop computer.
    /// </summary>
    SIID_DESKTOPPC = 94,
    /// <summary>
    /// A mobile computer (laptop).
    /// </summary>
    SIID_MOBILEPC = 95,
    /// <summary>
    /// The User Accounts Control Panel item.
    /// </summary>
    SIID_USERS = 96,
    /// <summary>
    /// Smart media.
    /// </summary>
    SIID_MEDIASMARTMEDIA = 97,
    /// <summary>
    /// CompactFlash media.
    /// </summary>
    SIID_MEDIACOMPACTFLASH = 98,
    /// <summary>
    /// A cell phone.
    /// </summary>
    SIID_DEVICECELLPHONE = 99,
    /// <summary>
    /// A digital camera.
    /// </summary>
    SIID_DEVICECAMERA = 100,
    /// <summary>
    /// A digital video camera.
    /// </summary>
    SIID_DEVICEVIDEOCAMERA = 101,
    /// <summary>
    /// An audio player.
    /// </summary>
    SIID_DEVICEAUDIOPLAYER = 102,
    /// <summary>
    /// Connect to network.
    /// </summary>
    SIID_NETWORKCONNECT = 103,
    /// <summary>
    /// The Network and Internet Control Panel item.
    /// </summary>
    SIID_INTERNET = 104,
    /// <summary>
    /// A compressed file with a .zip file name extension.
    /// </summary>
    SIID_ZIPFILE = 105,
    /// <summary>
    /// The Additional Options Control Panel item.
    /// </summary>
    SIID_SETTINGS = 106,
    /// <summary>
    /// Windows Vista with Service Pack 1 (SP1) and later. High definition DVD drive (any type - HD DVD-ROM, HD DVD-R, HD-DVD-RAM) that uses the HD DVD format.
    /// </summary>
    SIID_DRIVEHDDVD = 132,
    /// <summary>
    /// Windows Vista with SP1 and later. High definition DVD drive (any type - BD-ROM, BD-R, BD-RE) that uses the Blu-ray Disc format.
    /// </summary>
    SIID_DRIVEBD = 133,
    /// <summary>
    /// Windows Vista with SP1 and later. High definition DVD-ROM media in the HD DVD-ROM format.
    /// </summary>
    SIID_MEDIAHDDVDROM = 134,
    /// <summary>
    /// Windows Vista with SP1 and later. High definition DVD-R media in the HD DVD-R format.
    /// </summary>
    SIID_MEDIAHDDVDR = 135,
    /// <summary>
    /// Windows Vista with SP1 and later. High definition DVD-RAM media in the HD DVD-RAM format.
    /// </summary>
    SIID_MEDIAHDDVDRAM = 136,
    /// <summary>
    /// Windows Vista with SP1 and later. High definition DVD-ROM media in the Blu-ray Disc BD-ROM format.
    /// </summary>
    SIID_MEDIABDROM = 137,
    /// <summary>
    /// Windows Vista with SP1 and later. High definition write-once media in the Blu-ray Disc BD-R format.
    /// </summary>
    SIID_MEDIABDR = 138,
    /// <summary>
    /// Windows Vista with SP1 and later. High definition read/write media in the Blu-ray Disc BD-RE format.
    /// </summary>
    SIID_MEDIABDRE = 139,
    /// <summary>
    /// Windows Vista with SP1 and later. A cluster disk array.
    /// </summary>
    SIID_CLUSTEREDDRIVE = 140,

    /// <summary>
    /// The highest valid value in the enumeration. Values over 160 are Windows 7-only icons.
    /// </summary>
    SIID_MAX_ICONS = 175
}

我们开始!

创建一个实用程序包装。类名称和成员会有所不同，具体取决于您的要求。这是我的操作方法，但是随时进行所有必要的编辑:

public class IconUtils
{
    // copy DLL declarations above here...
    // ...

    // and copy again the XML summary here.
    public static bool DestroyIconH(IntPtr iconHandle)
    {
        return DestroyIcon(iconHandle);
    }

    /// <summary>
    /// Gets the Pointer to the (stock) Icon associated to the specified ID.
    /// </summary>
    /// <param name="StockIconID">Icon ID among the defined Stock ones.</param>
    /// <returns>The Pointer to the retrieved Icon. If no Icon were found, an empty Pointer is returned.</returns>
    private static IntPtr GetShellIconPointer(SHSTOCKICONID StockIconID, SHGSI IconOptions)
    {
        SHSTOCKICONINFO StkIconInfo = new SHSTOCKICONINFO();
        StkIconInfo.cbSize = Convert.ToUInt32(Marshal.SizeOf(typeof(SHSTOCKICONINFO)));

        if (SHGetStockIconInfo(StockIconID, IconOptions, StkIconInfo) == 0) {
            return StkIconInfo.hIcon;
        }

        return IntPtr.Zero;
    }

    /// <summary>
    /// Gets the (stock) Icon associated to the specified ID.
    /// </summary>
    /// <param name="StockIconID">Icon ID among the defined Stock ones.</param>
    /// <returns>The (stock) Icon. If no Icon were found, Null is returned.</returns>
    /// <remarks>WARNING ! Caller is responsible of calling Dispose() on the returned Icon.</remarks>
    public static Icon GetSystemIcon(SHSTOCKICONID stockIconID, SHGSI iconOptions)
    {
        IntPtr iconPointer = GetShellIconPointer(stockIconID, iconOptions);

        if (iconPointer != IntPtr.Zero) {
            Icon actualIcon = Icon.FromHandle(iconPointer);
            Icon iconCopy = (System.Drawing.Icon)actualIcon.Clone();

            actualIcon.Dispose();
            DestroyIcon(iconPointer);
            /*
                Honestly, I'm unsure of what I'm doing here :-(
                If I get rid of either actualIcon or iconCopy, 
                and don't make a copy of it, I get a 0x0 Icon.
                If I don't call DestroyIcon(h), I get a memory leak.
                I highly doubt a memory leak won't occur even with the trick above,
                but heh! >:-D honestly I don't care since 
                everything related to Icon retrieval in Windows 
                appears to me a very bad design pattern in the first place.
            */

            return iconCopy;
        } else {
            return null;
        }
    }

}

还为 System.Drawing.Bitmap创建扩展方法。默认的CreateThumbnail()不适合我的需求:

/// <summary>
/// Creates a Thumbnail of the Bitmap.
/// </summary>
/// <param name="sourceBitmap">Source Bitmap.</param>
/// <param name="width">Width for the Tumbnail.</param>
/// <param name="height">Height for the Tumbnail.</param>
/// <returns>Returns the created Thumbnail.</returns>
[Extension()]
public Bitmap CreateThumbnail(this Bitmap sourceBitmap, Int32 width, Int32 height)
{
    if (sourceBitmap == null) {
        return null; // Eat Exception !
    } else {
        if ((width > 0) && (height > 0)) {
            Rectangle layoutRectangle = new Rectangle(0, 0, width, height);
            Bitmap thumbnailBitmap = new Bitmap(width, height, sourceBitmap.PixelFormat);

            using (Graphics bmpGrphics = thumbnailBitmap.CreateGraphics()) {
                bmpGrphics.DrawImage(sourceBitmap, layoutRectangle);
            }

            return thumbnailBitmap;
        } else {
            return null;
        }
    }
}

工作原理:

在代码中的某处，您可以使用实用程序包装器:

您要查找的图标ID(SHSTOCKICONID值之一)

适合上下文的选项。

这是电话:

// You're looking for a 16x16 opened folder icon :
Icon icon16 = IconUtils.GetShellIcon(SHSTOCKICONID.SIID_FOLDEROPEN, SHGSI.SHGSI_ICON Or SHGSI.SHGSI_SMALLICON);

// You're looking for a 32x32 default state folder icon :
Icon icon32 = IconUtils.GetShellIcon(SHSTOCKICONID.SIID_FOLDER, SHGSI.SHGSI_ICON Or SHGSI.SHGSI_LARGEICON);

上面的PInvoke链接建议您使用 SHGSI.SHGSI_SMALLICON Or SHGSI.SHGSI_LARGEICON，但这不起作用(至少在我的系统上)。似乎未通过SHGSI_ICON标志将阻止在结构中正确设置图标句柄。而且我完全没有图标。

哦 !顺便说一下，在Windows 7(我使用的是Windows 7)中， SHSTOCKICONID.SIID_FOLDER和 SHSTOCKICONID.SIID_FOLDEROPEN由 完全相同的图标表示。 MS失败恕我直言!有时，我只是使用 SHSTOCKICONID.SIID_FOLDERBACK来显示 已关闭状态，但是您可以自由选择适合您(和用户)需求的状态。

额外的 :

现在您有了图标，我想您想在某个地方使用它们，例如将它们存储在两个ImageList中( imgList16和 imgList32-或类似)。通常，您将始终拥有16x16和32x32版本，并以适合您的显示器的格式返回(如MS广告所示)。但是我不指望，我总是检查一下我是否都:

// Get the two icons...
Icon dirIcon16 = Icon_Class.GetShellIcon(SHSTOCKICONID.SIID_FOLDEROPEN, SHGSI.SHGSI_ICON | SHGSI.SHGSI_SMALLICON);
Icon dirIcon32 = Icon_Class.GetShellIcon(SHSTOCKICONID.SIID_FOLDEROPEN, SHGSI.SHGSI_ICON | SHGSI.SHGSI_LARGEICON);

// Make sure you have both...
if (DirIcon16 == null) {
    if (DirIcon32 == null) {
        // both are missing... use a placeholder bitmap instead.
        // do the necessary changes and checks...
    } else {
        // at least the 32x32 is available.
        Bitmap iconBitmap32 = dirIcon32.ToBitmap();
        Bitmap iconBitmap16 = iconBitmap32.CreateThumbnail(16, 16);
        // now you can add both in two ImageList...
        imgList16.Images.Add("Directory_Opened", iconBitmap16);
        imgList32.Images.Add("Directory_Opened", iconBitmap32);
        dirIcon32.Dispose();
    }
} else {
    Bitmap iconBitmap16 = dirIcon16.ToBitmap();
    imgList16.Images.Add("Directory_Opened", iconBitmap16);

    if (dirIcon32 == null) {
        Bitmap iconBitmap32 = iconBitmap16.CreateThumbnail(32, 32);

        imgList32.Images.Add("Directory_Opened", iconBitmap32);
    } else {
        Bitmap iconBitmap32 = dirIcon32.ToBitmap();

        imgList32.Images.Add("Directory_Opened", iconBitmap32);
        dirIcon32.Dispose();
    }

    dirIcon16.Dispose();
}
// hence the extension above.

如您所见，所有这些都只为您提供16x16和32x32的图标。多年来，这是Windows的已知限制。应用程序(和几个Windows对话框)如何获得其他格式是完全不同的主题。您可以通过上述所有操作开始检索包含图标(库，单个图标或可执行文件)及其在资源中的索引的文件的路径。我建议您尝试使用 SHGSI枚举来检索这些信息。

然后，您必须自行提取必要的字节或流后，才必须实现 IconParser (请注意非标准尺寸的图标，请考虑尺寸大于255像素的图标，否则将没有任何有效的宽度/ header 中的高度数据，提防PNG压缩格式，在解析块时注意负值，不要忘了尽可能释放资源等)

好吧，也就是说，我很讨厌资源管理...对不起:/

祝你好运 !