String dir = "c:\";
String str = "Contenido de " + dir + "n";
TSearchRec sr;
bool finalizado = FindFirst(dir + "\*.*", faAnyFile, sr);
while (!finalizado)
{
    if (sr.Attr & faDirectory)
        str += "[" + sr.Name + "]n";
    else
        str += sr.Name + "n";

    finalizado = FindNext(sr);
}
FindClose(sr);
ShowMessage(str);