String ist nicht ereiterbar!!

[Sir Rufo]

... und so ... ?

Delphi-Quellcode:

function TForm3.GetUser: string;
var
  Size : DWORD;
  buffer : string;
begin
  Size := MAX_COMPUTERNAME_LENGTH + 1;
  SetLength( buffer, Size);
  if GetUserName(PChar( buffer ), Size) then
  begin
    SetLength( buffer, Size);
    Result := buffer;
  end else
    Result := '';
end;