Get file information using Delphi windows api - delphi

Question

Using Delphi and Windows API is possible from a PItemIDList to get if the file is a folder or not? With this snippet of code I can get the only the name of the file.
procedure TMain.FolderMonitorFileChange(aSender: TObject; aPIDL: PItemIDList);
var
FileInfo : SHFILEINFOW;
begin
SHGetFileInfo(LPCTSTR(aPIDL), 0 , FileInfo, SizeOf(FileInfo), SHGFI_PIDL or SHGFI_DISPLAYNAME or SHGFI_TYPENAME or SHGFI_ATTRIBUTES);
ShowMessage('File change notification: ' + FileInfo.szDisplayName + ' ' + FileInfo.szTypeName );
end;
Thanks

Answer 1

For a relative PIDL, you can obtain the IShellFolder interface of the PIDL's parent folder, and then pass the PIDL to the IShellFolder::GetAttributesOf() method.
function IsFolder(Parent: IShellFolder; aChildPIDL: PItemIDList): Boolean;
var
Attrs: SFGAOF;
begin
Result := Succeeded(Parent.GetAttributesOf(1, #aChildPidl, #Attrs))
and (Attrs and SFGAO_FOLDER <> 0);
end;
For an absolute PIDL, you have a few different options:
pass the PIDL to SHBindToParent() to convert it to a relative PIDL and retrieve its parent folder's IShellFolder, then call IShellFolder::GetAttributesOf().
function IsFolder(aPIDL: PItemIDList): Boolean;
var
Parent: IShellFolder;
Child: PItemIDList;
Attrs: SFGAOF;
begin
Result := Succeeded(SHBindToParent(aPidl, IShellFolder, #Parent, #Child))
and Succeeded(Parent.GetAttributesOf(1, #Child, #Attrs))
and (Attrs and SFGAO_FOLDER <> 0);
end;
pass the PIDL to SHGetFileInfo() using the SHGFI_PIDL flag. Enable the SHGFI_ATTRIBUTES flag to request the item's attributes.
function IsFolder(aPIDL: PItemIDList): Boolean;
var
FileInfo : SHFILEINFO;
begin
Result := (SHGetFileInfo(LPCTSTR(aPIDL), 0, #FileInfo, SizeOf(FileInfo), SHGFI_PIDL or SHGFI_ATTRIBUTES) <> 0)
and (FileInfo.dwAttributes and SFGAO_FOLDER <> 0);
end;
pass the PIDL to SHCreateItemFromIDList() to retrieve an IShellItem interface for it, and then call IShellItem::GetAttributes().
function IsFolder(aPIDL: PItemIDList): Boolean;
var
Item: IShellItem;
Attrs: SFGAOF;
begin
Result := Succeeded(SHCreateItemFromIDList(aPidl, IShellItem, #Item))
and Succeeded(Item.GetAttributes(SFGAO_FOLDER, #Attrs))
and (Attrs and SFGAO_FOLDER <> 0);
end;