如果Vista Shell中存在48×48或64×64图标，您可以使用SHGetFileInfo如何获取在timage中显示的句柄？

我想从一个代表文件夹路径的图像列表中选择一个图标，并在timage中显示一个48×48或64×64的图标。

// load the large system image for the current path into Image1
SHGetFileInfo( PChar( CurrentPath ),FILE_ATTRIBUTE_norMAL,SFI,SizeOf( TSHFileInfo ),SHGFI_ICON or SHGFI_LARGEICON or SHGFI_SHELLICONSIZE or
             SHGFI_SYSICONINDEX or SHGFI_TYPENAME or SHGFI_disPLAYNAME );
aimageIndex := SFI.iIcon;
ImageList2.GetBitmap( aimageIndex,Image1.Picture.Bitmap );

法案

您必须使用 SHGetImageList功能，以获得具有较大图标的图像列表。

这里有一个例子在delphi中

uses ShellApi,Commctrl,ShlObj;

const
  SHIL_LARGE     = $00;  //The image size is normally 32x32 pixels. However,if the Use large icons option is selected from the Effects section of the Appearance tab in display Properties,the image is 48x48 pixels.
  SHIL_SMALL     = $01;  //These images are the Shell standard small icon size of 16x16,but the size can be customized by the user.
  SHIL_EXTRALARGE= $02;  //These images are the Shell standard extra-large icon size. This is typically 48x48,but the size can be customized by the user.
  SHIL_SYSSMALL  = $03;  //These images are the size specified by GetSystemMetrics called with SM_CXSMICON and GetSystemMetrics called with SM_CYSMICON.
  SHIL_JUMBO     = $04;  //Windows Vista and later. The image is normally 256x256 pixels.
  IID_IImageList: TGUID= '{46EB5926-582E-4017-9FDF-E8998DAA0950}';

function GetimageListSH(SHIL_FLAG:Cardinal): HIMAGELIST;
type
  _SHGetimageList = function (iImageList: integer; const riid: TGUID; var ppv: Pointer): hResult; stdcall;
var
  Handle        : THandle;
  SHGetimageList: _SHGetimageList;
begin
  Result:= 0;
  Handle:= LoadLibrary('Shell32.dll');
  if Handle<> S_OK then
  try
    SHGetimageList:= GetProcAddress(Handle,PChar(727));
    if Assigned(SHGetimageList) and (Win32Platform = VER_PLATFORM_WIN32_NT) then
      SHGetimageList(SHIL_FLAG,IID_IImageList,Pointer(Result));
  finally
    FreeLibrary(Handle);
  end;
end;


Procedure GetIconFromFile(aFile:String; var aIcon : TIcon;SHIL_FLAG:Cardinal);
var
  aimgList    : HIMAGELIST;
  SFI         : TSHFileInfo;
Begin
    //Get the index of the imagelist
    SHGetFileInfo(PChar(aFile),SHGFI_ICON or SHGFI_LARGEICON or SHGFI_SHELLICONSIZE or
                 SHGFI_SYSICONINDEX or SHGFI_TYPENAME or SHGFI_disPLAYNAME );

    if not Assigned(aIcon) then
    aIcon:= TIcon.Create;
    //get the imagelist
    aimgList:= GetimageListSH(SHIL_FLAG);
    //extract the icon handle
    aIcon.Handle:= ImageList_GetIcon(aimgList,Pred(ImageList_GetimageCount(aimgList)),ILD_norMAL);
End;

你可以这样使用这些功能

var
 hicon :TIcon;
begin
    hicon:= TIcon.Create;
    try
     GetIconFromFile('C:\Tools\reflector\readme.htm',hicon,SHIL_JUMBO);
     Image1.Picture.Icon.Assign(hIcon); //assign to timage
    finally
     hIcon.Free;
    end;
end;

参见英文答案 > How can I multiply 64 bit operands and get 128 bit result portably?2个
在C/C++中有一个合理的可移植方式来为128位结果乘以两个64位整数并得到结果的前64位而不是底部的64位吗？我需要这个来在任意大小的表上分配哈希函数.

这个答案显示了如何在不支持128位整数的系统上从64×64位乘法获得(精确)前64位. @amdn的答案将在支持128位整数的系统上提供更好的性能.

下图显示了一种从两个64位数字计算128位乘积的方法.每个黑色矩形代表一个64位数字.方法的64位输入X和Y被分成标记为a,b,c和d的32位块.然后执行四次32×32位乘法,得到四个标记为a * c,b * c,a * d和b * d的64位乘积.必须移动并添加四个产品以计算最终答案.

请注意,128位乘积的低32位仅由部分乘积b * d的低32位决定.接下来的32位由以下的低32位决定

mid34 = ((b*c) & 0xffffffff) + ((a*d) & 0xffffffff) + ((b*d) >> 32);

请注意,mid34是三个32位数的总和,因此实际上是一个34位的总和. mid34的高两位充当64×64位乘法的前64位的进位.

这将我们带到演示代码. top64函数计算64×64乘法的高64位.允许在注释中显示较低64位的计算有点冗长.主函数利用128位整数通过简单的测试用例验证结果.进一步的测试留给读者练习.

#include <stdio.h>#include <stdint.h>typedef unsigned __int128 uint128_t;uint64_t top64( uint64_t x,uint64_t y ){    uint64_t a = x >> 32,b = x & 0xffffffff;    uint64_t c = y >> 32,d = y & 0xffffffff;    uint64_t ac = a * c;    uint64_t bc = b * c;    uint64_t ad = a * d;    uint64_t bd = b * d;    uint64_t mid34 = (bd >> 32) + (bc & 0xffffffff) + (ad & 0xffffffff);    uint64_t upper64 = ac + (bc >> 32) + (ad >> 32) + (mid34 >> 32);//  uint64_t lower64 = (mid34 << 32) | (bd & 0xffffffff);    return upper64;}int main( void ){    uint64_t x = 0x0000000100000003;    uint64_t y = 0x55555555ffffffff;    uint128_t m = x,n = y;    uint128_t p = m * n;    uint64_t top = p >> 64;    printf( "%016llx %016llx\n",top,top64( x,y ) );}

我找到了关于获取文件甚至文件扩展名的系统映像的各种文章.我有以下方法,用于获取小型16×16和大型32×32图像.

// DLL Import
    [DllImport("shell32")]
    private static extern IntPtr SHGetFileInfo(
        string pszPath,uint dwFileAttributes,ref SHFILEINFO psfi,uint cbFileInfo,uint uFlags);

    // Constants/Enums
    private const int FILE_ATTRIBUTE_norMAL = 0x80;

    private enum SHGetFileInfoConstants : int
    {
        SHGFI_ICON = 0x100,// get icon
        SHGFI_disPLAYNAME = 0x200,// get display name
        SHGFI_TYPENAME = 0x400,// get type name
        SHGFI_ATTRIBUTES = 0x800,// get attributes
        SHGFI_ICONLOCATION = 0x1000,// get icon location
        SHGFI_EXETYPE = 0x2000,// return exe type
        SHGFI_SYSICONINDEX = 0x4000,// get system icon index
        SHGFI_LINKOVERLAY = 0x8000,// put a link overlay on icon
        SHGFI_SELECTED = 0x10000,// show icon in selected state
        SHGFI_ATTR_SPECIFIED = 0x20000,// get only specified attributes
        SHGFI_LARGEICON = 0x0,// get large icon
        SHGFI_SMALLICON = 0x1,// get small icon
        SHGFI_OPENICON = 0x2,// get open icon
        SHGFI_SHELLICONSIZE = 0x4,// get shell size icon
        SHGFI_PIDL = 0x8,// pszPath is a pidl
        SHGFI_USEFILEATTRIBUTES = 0x10,// use passed dwFileAttribute
        SHGFI_ADDOVERLAYS = 0x000000020,// apply the appropriate overlays
        SHGFI_OVERLAYINDEX = 0x000000040   // Get the index of the overlay
    }

    public static Icon GetSmallIconForExtension(string extension)
    {
        // Get the small icon and clone it,as we MUST destroy the handle when we are done.
        SHFILEINFO shinfo = new SHFILEINFO();
        IntPtr ptr = SHGetFileInfo(
            extension,FILE_ATTRIBUTE_norMAL,ref shinfo,(uint)Marshal.SizeOf(shinfo),(int)(SHGetFileInfoConstants.SHGFI_ICON |
            SHGetFileInfoConstants.SHGFI_SMALLICON |
            SHGetFileInfoConstants.SHGFI_USEFILEATTRIBUTES |
            SHGetFileInfoConstants.SHGFI_TYPENAME));
        Icon icon = Icon.FromHandle(shinfo.hIcon).Clone() as Icon;
        DestroyIcon(shinfo.hIcon);
        return icon;
    }

    public static Icon GetLargeIconForExtension(string extension)
    {
        // Get the small icon and clone it,(int)(
            SHGetFileInfoConstants.SHGFI_ICON |
            SHGetFileInfoConstants.SHGFI_LARGEICON |
            SHGetFileInfoConstants.SHGFI_USEFILEATTRIBUTES |
            SHGetFileInfoConstants.SHGFI_TYPENAME
            ));
        Icon icon = Icon.FromHandle(shinfo.hIcon).Clone() as Icon;
        DestroyIcon(shinfo.hIcon);
        return icon;
    }

从上述方法之一获取图标后,我将其转换为位图,如下所示：

Image image = icon.ToBitmap();

在上面指定SHGetFileInfoConstants.SHGFI_LARGEICON时,我得到32×32大小的位图图像.但是,在Windows资源管理器中,当您选择查看中等图标时,您将获得48×48大小的图标.

我想要48×48大小的图标(不是32×32).我需要做什么？

shell图标的大小在 SHGetImageList的文档中给出：

> 16×16 =小
> 32×32 =大
> 48×48 = extralarge
> 256×256 = jumbo

所以当你要求“大”图标时,你会得到32×32.如果你想要超大图标,你需要从SHIL_EXTRALARGE图像列表中获取它们.