[델파이] TIdHTTP JSON 형식 POST - 바이너리 파일 받아오기

uese 
  IdHTTP; //추가
 
...
 
procedure TfrmSelvas.btnSaveClick(Sender: TObject);
var
  IDhttp: TIdHTTP;
  TRequest : TstringStream;
  TOut : TstringStream;
  URL, sString : String;
begin
  try
    IDhttp := TIdHTTP.Create(nil);
    URL := 'http://localhost:8080/pierrot/api';
 
    TRequest := TStringStream.Create('');
    TOut := TStringStream.Create('');
 
    IDhttp.ConnectTimeout      := 3000;
    IDhttp.ReadTimeout         := 3000;
    IDhttp.Request.ContentType := 'application/json;charset=UTF-8';
 
 
    TRequest.Clear;
    TOut.Clear;
 
 
    sString := '';
    sString := '{                                   '+#13#10+
             '   "FileName": "Pierrot.pdf",       '+#13#10+
              '   "Dir": "C:\dir"                  '+#13#10+
             '}                                   ';
 
    TRequest.WriteString(sString);
 
    TRequest.Position := 0;
 
    IDhttp.Post(URL, TRequest, TOut);
 
    TOut.SaveToFile('C:\pierrot.pdf');
  finally
    IDhttp.Free;
    TRequest.Free;
    TOut.Free;
  end;
end;