Flutter：多部分文件请求不起作用

Question

我想通过多部分文件请求上传图片。使用此代码当我传递两个图像文件时，它工作正常。但是当我想传递一个图像文件而另一个图像文件为空时，它就不起作用了。问题出在哪里？我该如何解决这个问题？

这是我的代码 -

Future<Map<String, dynamic>> updateprofile(
      UpdateProfileInfo updateProfileInfo,
      File imageFile,
      File signatureFile) async {

    String url = "$baseAPIUrl/update-profile-info";
    String _token = await SavedData().loadToken();
    String authorization = "Bearer $_token";

    final headers = {
      'Content-Type': 'application/json',
      'Accept': 'application/json',
      "Authorization": authorization
    };

    var request = http.MultipartRequest("POST", Uri.parse(url));

    request.headers.addAll(headers);
    request.fields.addAll(updateProfileInfo.toJson());

    request.files
        .add(await http.MultipartFile.fromPath('image', imageFile.path));
    request.files.add(
        await http.MultipartFile.fromPath('signature', signatureFile.path));

    print(" Update Profile Json ${updateProfileInfo.toJson()}");
    print("Request Fields ${request.fields}");
    http.StreamedResponse response = await request.send();

    String respStr = await response.stream.bytesToString();
    dynamic respJson;

    try {
      respJson = jsonDecode(respStr);
    } on FormatException catch (e) {
      print(e.toString());
    }

    print('API ${response.statusCode}\n  $respJson');

    bool isSuccess = response.statusCode == 200;
    var data = json.decode(respStr);

    return {
      'isSuccess': isSuccess,
      "message": isSuccess ? data["success"]["message"] : null,
      "name": isSuccess ? data["success"]["name"] : null,
      "classgroup": isSuccess ? data["success"]["classgroup"] : null,
      "image": isSuccess ? data["success"]["image"] : null,
      "error": isSuccess ? null : data['error']['message'],
    };
  }

这是邮递员截图

1.

2。 POSTMAN 为 Dart 生成的代码 - http

Answer 1

使用 dio 包应该可以工作

   Future<bool> updateImage(var pickedFile) async {
    SharedPreferences sharedPreferences = await SharedPreferences.getInstance();` <br/>
    var token = sharedPreferences.getString("token");
    Dio dio = Dio(); 
    final File file = File(pickedFile.path);
   String fileName = file.path.split('/').last;
   dio.options.headers["authorization"] = token;
   FormData formData = FormData.fromMap({
     "image": await MultipartFile.fromFile(file.path),
     });
    try {
     var response = await dio.post(API.kBASE_URL, data: formData);
           if (response.statusCode == 200) {
           return true;
           } else {
                   return false;
                 }
          } catch (r) {
                        return false;
                       }
     }

Answer 2

当您的文件之一为空时，您应该避免将其添加到请求正文中。

if(imageFile != null){
    request.files
        .add(await http.MultipartFile.fromPath('image', imageFile.path));
}
if(signatureFile != null){
request.files.add(
        await http.MultipartFile.fromPath('signature', signatureFile.path));
}

因为signatureFile.path这里会出错

Flutter：多部分文件请求不起作用

Flutter : Multipart File request not working

api

http

multipart

flutter