Пожалуйста, используйте flutter_upload пакет для загрузки файла
Или используйте ниже код для загрузки файла, используя multipart:
static Future<String> fileUploadMultipart(
{File file, OnUploadProgressCallback onUploadProgress}) async {
assert(file != null);
final url = '$baseUrl/api/file';
final httpClient = getHttpClient();
final request = await httpClient.postUrl(Uri.parse(url));
int byteCount = 0;
var multipart = await http.MultipartFile.fromPath(fileUtil.basename(file.path), file.path);
// final fileStreamFile = file.openRead();
// var multipart = MultipartFile("file", fileStreamFile, file.lengthSync(),
// filename: fileUtil.basename(file.path));
var requestMultipart = http.MultipartRequest("", Uri.parse("uri"));
requestMultipart.files.add(multipart);
var msStream = requestMultipart.finalize();
var totalByteLength = requestMultipart.contentLength;
request.contentLength = totalByteLength;
request.headers.set(
HttpHeaders.contentTypeHeader, requestMultipart.headers[HttpHeaders.contentTypeHeader]);
Stream<List<int>> streamUpload = msStream.transform(
new StreamTransformer.fromHandlers(
handleData: (data, sink) {
sink.add(data);
byteCount += data.length;
if (onUploadProgress != null) {
onUploadProgress(byteCount, totalByteLength);
// CALL STATUS CALLBACK;
}
},
handleError: (error, stack, sink) {
throw error;
},
handleDone: (sink) {
sink.close();
// UPLOAD DONE;
},
),
);
await request.addStream(streamUpload);
final httpResponse = await request.close();
//
var statusCode = httpResponse.statusCode;
if (statusCode ~/ 100 != 2) {
throw Exception('Error uploading file, Status code: ${httpResponse.statusCode}');
} else {
return await readResponseAsString(httpResponse);
}
}