Question

I just discovered that some programs are very quick when getting/listing the directory of network drives, almost instantly. I am talking about programs like FreeComanderXE and DirectoryOpus here.

In my program it takes several seconds to do the same task. What can I do to improve the speed here.

This is my code for loading the directory in a thread:

procedure LoadDirThread.Execute;
var
  PIdx: Integer;
  b: Boolean;
  n: Integer;
  FName: string;
  Item: TXplorerItem;
  i: Integer;
  Path: String;
  SR: TSearchRec;
  SFI: TSHFileInfo;
  FData: TXplorerItem;
begin
  inherited;
  if not XPlorerLink.Loaded then
  begin
    Path := XPlorerLink.Path;
    PIdx := XPlorerLink.PathList.IndexOf(Path);
    if PIdx = -1 then
      PIdx := XPlorerLink.PathList.Add(Path);

    if FindFirst(Path + '*.*', faAnyFile - faHidden, SR) = 0 then
    begin
      repeat
        if (SR.Name <> '.') and (SR.Name <> '..') then
        begin
          if (SR.Attr and faDirectory <> 0) then
          begin
            FData := TXplorerItem.Create;
            FName := Path + SR.Name;
            SHGetFileInfo(PChar(FName), 0, SFI, SizeOf(SFI), SHGFI_DISPLAYNAME or
              SHGFI_TYPENAME);
            FData.FAttr:= SR.Attr;
            FData.Kind := xiDir;
            FData.Size := 0;
            FData.Caption := Strpas(SFI.szDisplayName);
            if FData.Caption = '' then
              FData.Caption := ChangeFileExt(SR.Name, '');
            FData.Name := SR.Name;
            FData.Modified := FileDateToDateTime(SR.Time);
            FData.ImgIdx := -1;
            n := XPlorerLink.InfoList.IndexOf(SFI.szTypeName);
            if n = -1 then
              n := XPlorerLink.InfoList.Add(SFI.szTypeName);
            FData.InfoIdx := n;
            FData.PathIdx := PIdx;
            XPlorerLink.Items.Add(FData);
          end
          else
          if (SR.Attr and faDirectory = 0) then
          begin
            FData := TXplorerItem.Create;
            FName := Path + SR.Name;
            SHGetFileInfo(PChar(FName), 0, SFI, SizeOf(SFI), SHGFI_DISPLAYNAME or
              SHGFI_TYPENAME);
            FData.FAttr:= SR.Attr;
            FData.Kind := xiFile;
            FData.Size := SR.Size;
            FData.Caption := Strpas(SFI.szDisplayName);
            if FData.Caption = '' then
              FData.Caption := ChangeFileExt(SR.Name, '');
            FData.Name := SR.Name;
            FData.Modified := FileDateToDateTime(SR.Time);
            FData.ImgIdx := -1;
            n := XPlorerLink.InfoList.IndexOf(SFI.szTypeName);
            if n = -1 then
              n := XPlorerLink.InfoList.Add(SFI.szTypeName);
            FData.InfoIdx := n;
            FData.PathIdx := PIdx;
            XPlorerLink.Items.Add(FData);
          end;
        end;
      until (FindNext(SR) <> 0) or Terminated;
      FindClose(SR);
    end;
  end;
  if not Terminated then
    PostMessage(frmMain.Handle, CM_UPDATEVIEW, -2, Integer(XPlorerLink));
end;

Answer 1

Change your code to use the IShellFolder interface instead of the Find...() functions. Everything in the Windows Shell is internally represented by IShellFolder, ITEMIDLISTs, etc, even file system and network paths. When performance matters, use Windows’ own native data. Windows Explorer uses IShellFolder and related interfaces for all of its main work.