可以从Vista Shell获得48x48或64x64图标吗？

Question

如果Vista Shell中存在48x48或64x64图标,您如何使用SHGetFileInfo获取在TImage中显示一个图标的句柄？

我想从图像列表中选择一个代表文件夹路径的图标,并在Timage中显示48x48或64x64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

Answer 1

您必须使用SHGetImageList函数来获取具有较大图标的图像列表.

这里有一个delphi的例子

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), FILE_ATTRIBUTE_NORMAL, SFI,
                 SizeOf( TSHFileInfo ), 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;

您可以通过这种方式使用这些功能

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;

Answer 2

在这里阅读:( C++中的代码)

在Windows上获取16×16和32×32图标相对容易,并且通常与调用ExtractIconEx一样简单.

然而,分别由XP和Vista引入的超大(48×48)和巨型(256×256)图标略微复杂.这通常通过以下方式完成:

1. 使用SHGetFileInfo获取给定文件的文件信息,特别是图标索引
2. 检索存储所有图标的系统映像列表
3. 将图像列表转换为IImageList接口并从那里获取图标