上传 Image/File 到 Strapi (Flutter Web)

Question

我正在尝试通过 Flutter Web 将图像上传到 Strapi。我知道（从这个 link) that I need to use FormData to do so. I've researched on many ways to do this and I stumble across Dio and of course Http.

两种解决方案都给我错误： Unsupported operation: MultipartFile is only supported where dart:io is available.

我试过这个代码：

var request = new http.MultipartRequest("POST", Uri.parse(url));
    request.files.add(
      await http.MultipartFile.fromPath(
        "files",
        imageFilePath,
      ),
    );
    request.send().then((response) {
      if (response.statusCode == 200) print("Uploaded!");
      print(response.statusCode);
    }).catchError((e) => print(e));

按照建议here。

当我使用 MultipartFile.fromBytes(...).

时，还有许多其他错误或空数据 (400)

我只是想上传一个文件，因此我假设我的正文应该只包含 files 的 FormData，正如 Strapi's Documentation.

中提到的那样

Answer 1

所以，我在 Flutter Discord 上搜索了一些帮助，我发现我的问题是因为 Flutter Web 无法使用 'dart:io' ，而使用 'dart:html' 会取消所有的使用Flutter 平台的数量。

我最终使用了这个导入：

import 'dart:convert';
import 'dart:typed_data';
import 'package:image_picker/image_picker.dart';
import 'package:http/http.dart' as http;
import 'package:http_parser/http_parser.dart';
import 'package:path/path.dart';
import 'package:async/async.dart';

这是我创建并运行的函数：

 Future<bool> uploadImage(
    String imageFilePath,
    Uint8List imageBytes,
  ) async {
    String url = SERVERURL + "/uploadRoute";
    PickedFile imageFile = PickedFile(imageFilePath);
    var stream =
        new http.ByteStream(DelegatingStream.typed(imageFile.openRead()));

    var uri = Uri.parse(url);
    int length = imageBytes.length;
    var request = new http.MultipartRequest("POST", uri);
    var multipartFile = new http.MultipartFile('files', stream, length,
        filename: basename(imageFile.path),
        contentType: MediaType('image', 'png'));

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

我在使用 Strapi 时遇到了这个问题，这个解决方案非常有效。

Answer 2

在使用 Flutter 创建条目期间上传文件

dio: ^3.0.10、mime: ^1.0.0 和 http_parser.

如果是foo，主要部分是文件的键名，所以你必须把files.image改成files.foo才能上传

final mimeType = mime.lookupMimeType(imageFile.path, headerBytes: [0xFF, 0xD8])?.split('/');

FormData formData = new FormData.fromMap(
  {
    "files.image": await MultipartFile.fromFile(
      imageFile.path,
      filename: imageFile.path.split('/').last,
      contentType: MediaType(mimeType?[0], mimeType?[1]),
    ),
    "data": jsonEncode({
      "title": title,
      "summary": summary,
      "content": content,
    }),
  },
);

Response response = await _dio.post(
  "/blogs",
  data: formData,
  options: Options(),
);

Answer 3

在 Flutter Web 中：
我正在使用 node.js 和 express 作为后端源我创建了以下简单方法来上传 图像和文本数据 到 localhost 服务器使用xamp

String url = 'http://localhost:8080/blog_upload';
    var request = http.MultipartRequest('POST', Uri.parse(url));
    imagebytes = await image.readAsBytes();
    List<int> listData = imagebytes!.cast();
    request.files.add(http.MultipartFile.fromBytes('field_name', listData ,
        filename:'myFile.jpg'));
 request.fields['name'] = 'Mehran Ullah Khan';
 request.fields['country'] = 'Pakistan';
    var response = await request.send();

我在上面的方法中使用了如下依赖

 http: ^0.13.3
 image_picker: ^0.8.2

我们如何使用image_picker？首先全局声明 image 和 imagebytes

image = await ImagePicker().pickImage(source: ImageSource.gallery);

这是我在后端使用的方法。

app.post('/blog_upload', upload.single('field_name'), async (req, res, next) => {
  let data = {name_db: req.body['name'],    Country_db:req.body['country'],};
    let sqlq = `INSERT INTO TableName SET ? `;
    db.query(sqlq, data, (insertionErr, insertionResult) => {
      if (insertionErr) {
        console.log('failed_upload');
        throw insertionErr;
      }
      else {
        console.log('done_upload');
        res.send(insertionResult);  
      }
    });
  });

上面的方法我都用过 multer and express 包您可以在此 link

中查看有关 multer 和 express 的完整详细信息

Answer 4

@Diego Cattarinich Clavel

字符串url = Constants.BASE_URL + HttpUrls.categories; PickedFile imageFile = PickedFile(路径); 变量流 = 新 http.ByteStream(DelegatingStream.typed(imageFile.openRead()));

var uri = Uri.parse(url);
int length = imageBytes.length;
var request = new http.MultipartRequest(
  "PUT",
  uri,
);

var multipartFile = new http.MultipartFile(
  'files.categoryImage',
  stream,
  length,
  filename: basename(imageFile.path),
  contentType: MediaType('image', 'png'),
);

request.files.add(multipartFile);
request.fields['data'] = '{"category":$category}';
print(request.url);

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

上传 Image/File 到 Strapi (Flutter Web)

Upload Image/File to Strapi (Flutter Web)

flutter

form-data

strapi

dio

flutter-http