dart - Flutter image_picker post上传图片

Question

我正在使用 Flutter 插件 Image_picker 选择图片，以便我想在选择图片后上传图片

Future<File> _imageFile;

  void _onImageButtonPressed(ImageSource source) async {
    setState(() {
      _imageFile = ImagePicker.pickImage(source: source);
    });
  }

我在 flutter documentation 中找到这段代码但它不起作用

var uri = Uri.parse("http://pub.dartlang.org/packages/create");
var request = new http.MultipartRequest("POST", url);
request.fields['user'] = 'nweiz@google.com';
request.files.add(new http.MultipartFile.fromFile(
    'package',
    new File('build/package.tar.gz'),
    contentType: new MediaType('application', 'x-tar'));
request.send().then((response) {
  if (response.statusCode == 200) print("Uploaded!");
});

Answer 1

使用MultipartRequest类

Upload(File imageFile) async {    
    var stream = new http.ByteStream(DelegatingStream.typed(imageFile.openRead()));
      var length = await imageFile.length();

      var uri = Uri.parse(uploadURL);

     var request = new http.MultipartRequest("POST", uri);
      var multipartFile = new http.MultipartFile('file', stream, length,
          filename: basename(imageFile.path));
          //contentType: new MediaType('image', 'png'));

      request.files.add(multipartFile);
      var response = await request.send();
      print(response.statusCode);
      response.stream.transform(utf8.decoder).listen((value) {
        print(value);
      });
    }

检查这个answer