flutter - 在Flutter网站中上传图片

Question

Flutter Web仍处于技术预览中，但我想从磁盘中选择一个图像并将其上传到服务器。无论如何，有没有将HTML，JS添加到我的Flutter网站项目中并与之交互？

Answer 1

您需要addEventListener，还需要附加它以便在移动Safari中将其唤醒。我回答了here too。

Future<void> _setImage() async {
    final completer = Completer<List<String>>();
    InputElement uploadInput = FileUploadInputElement();
    uploadInput.multiple = true;
    uploadInput.accept = 'image/*';
    uploadInput.click();
    // onChange doesn't work on mobile safari
    uploadInput.addEventListener('change', (e) async {
        // read file content as dataURL
        final files = uploadInput.files;
        Iterable<Future<String>> resultsFutures = files.map((file) {
            final reader = FileReader();
            reader.readAsDataUrl(file);
            reader.onError.listen((error) => completer.completeError(error));
            return reader.onLoad.first.then((_) => reader.result as String);
        });

        final results = await Future.wait(resultsFutures);
        completer.complete(results);
    });
    // need to append on mobile safari
    document.body.append(uploadInput);
    final List<String> images = await completer.future;
    setState(() {
        _uploadedImages = images;
    });
    uploadInput.remove();
}

这也适用:

Future<void> _setImage() async {   
    final completer = Completer<List<String>>();
    final InputElement input = document.createElement('input');
    input
      ..type = 'file'
      ..multiple = true
      ..accept = 'image/*';
    input.click();
    // onChange doesn't work on mobile safari
    input.addEventListener('change', (e) async {
      final List<File> files = input.files;
      Iterable<Future<String>> resultsFutures = files.map((file) {
        final reader = FileReader();
        reader.readAsDataUrl(file);
        reader.onError.listen((error) => completer.completeError(error));
        return reader.onLoad.first.then((_) => reader.result as String);
      });
      final results = await Future.wait(resultsFutures);
      completer.complete(results);
    });
    // need to append on mobile safari
    document.body.append(input);
    // input.click(); can be here
    final List<String> images = await completer.future;
    setState(() {
      _uploadedImages = images;
    });
    input.remove();
}