void _upload() async {
    if (_image == null) return;
    String base64Image = base64Encode(_image.readAsBytesSync());
    String fileName = _image.path.split("/").last;

    var stream = new http.ByteStream(DelegatingStream.typed(_image.openRead()));
    // get file length
    var length = await _image.length();
    var request = new http.MultipartRequest("POST", Uri.parse("$baseUrl/basic/upload"));
    var multipartFile = new http.MultipartFile('file', stream, length,
        filename: basename(_image.path));

    request.files.add(multipartFile);
    request.fields['komentar']='KOmentar';
    request.fields['long']=longitude.toString();
    request.fields['lat']=latitude.toString();
    request.fields['id_user']='xxll';
    request.fields['waktu']='2019-05-02 01:01:01';
    request.fields['username']='32324';
    // send
    var response = await request.send();
    print(response.statusCode);

    // listen for response
    response.stream.transform(utf8.decoder).listen((value) {
      print(value);
    });

}