Delphi - Get folder icon - delphi

Question

How i can get the icon of special folder for example Desktop
function GetFolderIcon( FName: string ): integer;
var
FInfo: TSHFileInfo;
begin
if SHGetFileInfo(pChar(FName), FILE_ATTRIBUTE_NORMAL, FInfo, SizeOf(FInfo),
SHGFI_SYSICONINDEX or SHGFI_SMALLICON or SHGFI_USEFILEATTRIBUTES or SHGFI_PIDL or SHGFI_ICON or SHGFI_OPENICON ) <> 0 then begin
Result := FInfo.iIcon
end
else
Result := -1;
end;
GetFolderIcon(GetSpecialFolder(CSIDL_DESKTOP)); retern -1

Answer 1

CSIDL_DESKTOP is the "virtual folder that represents the Windows desktop, the root of the namespace". As such, it does not have a filesystem path that you can pass to SHGetFileInfo(). You are probably thinking of CSIDL_DESKTOPDIRECTORY instead, which is "The file system directory used to physically store file objects on the desktop (not to be confused with the desktop folder itself)":
GetFolderIcon(GetSpecialFolder(CSIDL_DESKTOPDIRECTORY));
When calling SHGetFileInfo(), you can specify the SHGFI_PIDL flag so you can pass a PIDL instead of a filesystem path. That allows for querying virtual items. Your code is already using SHGFI_PIDL, but it is not using any PIDLs, which means you are using SHGetFileInfo() incorrectly to begin with.
Try this:
uses
..., ShlObj, SHFolder;
function GetSpecialFolderPath(FolderID: Integer): String;
var
Path: array[0..MAX_PATH] of Char;
begin
if SHGetFolderPath(0, FolderID, nil, SHGFP_TYPE_CURRENT, Path) = 0 then
Result := Path
else
Result := '';
end;
function GetSpecialFolderPidl(FolderID: Integer): PItemIDList;
begin
Result := nil;
SHGetSpecialFolderLocation(0, FolderID, Result);
end;
function GetFolderIcon( FName: String ): integer; overload;
var
FInfo: TSHFileInfo;
begin
ZeroMemory(#FInfo, SizeOf(FInfo));
if SHGetFileInfo(PChar(FName), FILE_ATTRIBUTE_NORMAL, FInfo, SizeOf(FInfo), SHGFI_USEFILEATTRIBUTES or SHGFI_SYSICONINDEX or SHGFI_SMALLICON or SHGFI_ICON or SHGFI_OPENICON ) <> 0 then
begin
Result := FInfo.iIcon;
if FInfo.hIcon <> 0 then DestroyIcon(FInfo.hIcon);
end else
Result := -1;
end;
function GetFolderIcon( Pidl: PItemIDList ): integer; overload;
var
FInfo: TSHFileInfo;
begin
if SHGetFileInfo(PChar(Pidl), FILE_ATTRIBUTE_NORMAL, FInfo, SizeOf(FInfo), SHGFI_PIDL or SHGFI_USEFILEATTRIBUTES or SHGFI_SYSICONINDEX or SHGFI_SMALLICON or SHGFI_ICON or SHGFI_OPENICON ) <> 0 then
begin
Result := FInfo.iIcon;
if FInfo.hIcon <> 0 then DestroyIcon(FInfo.hIcon);
end
else
Result := -1;
end;
var
Icon: Integer;
Pidl: PItemIDList;
begin
Icon := -1;
Pidl := GetSpecialFolderPidl(CSIDL_DESKTOP);
if Pidl <> nil then
try
Icon := GetFolderIcon(Pidl);
finally
CoTaskMemFree(Pidl);
end;
end;
var
Icon: Integer;
Path: string;
begin
Icon := -1;
Path := GetSpecialFolderPath(CSIDL_DESKTOPDIRECTORY);
if Path <> '' then
Icon := GetFolderIcon(Path);
end;