[Flutter 錯誤] - 期望“String”類型的值，但在嘗試將圖像發送到服務器時得到“XFile”類型之一錯誤

Question

因此，我嘗試使用圖像選擇器和 select 從圖庫中獲取圖像，並使用 REST API 將其發送到服務器。從圖庫中選擇的圖像是 XFILE 格式。

BLOC function 將圖像發送到服務器：

  Future<void> _onPaymentSlipSubmitEvent(
      PaymentSlipSubmitEvent event, Emitter<BankTransferScreenState> emit) async {
    try {
      final ApiResponse apiResponse = await courseRepo.sendBankSlip(BankSlipRequest(courseId: state.courseId,slip:event.slip,paidAmount:state.amount));
      if (apiResponse.status) {
      }
    } on Exception catch (e) {
      snackBarBloc.add(OpenSnackBar(e.toString()));
     }
    }

存儲庫 function：

    Future<ApiResponse> sendBankSlip(BankSlipRequest bankSlipRequest) async {
    final ApiResponse apiResponse = await restServiceProvider.post("/courses/create-payment", bankSlipRequest.toJson());
    return apiResponse;
    }

BankSlipRequest class：

    import 'package:care_giver_app/models/api_request.dart';
    import 'package:image_picker/image_picker.dart';

    class BankSlipRequest extends ApiRequest{
      String courseId="";
      XFile? slip;
      String paidAmount="";

      BankSlipRequest({required this.courseId,required this.slip,required this.paidAmount});

       BankSlipRequest.fromJson(Map<String, dynamic> json) {
         courseId = json['course_Id'];
         slip = json['proof_image'];
         paidAmount = json['paid_amount'];
       }

       Map<String, dynamic> toJson() => {
        "course_Id": courseId,
        "proof_image": slip,
        "paid_amount": paidAmount,
        };
       }

我的 RestServiceProvider class 中的 POST 方法將文件發送到服務器：

Future<ApiResponse> post(String url, dynamic body) async {
    logger.i('Api Post, url $_url$url');
    logger.i('Api Post, data ${body.toString()}');
    ApiResponse apiResponse;
    try {
      final response =
          await http.post(Uri.parse(_url + url), body: body, headers: _headers);
      apiResponse = _returnResponse(response);
    } on SocketException {
      logger.e('No net');
      throw FetchDataException('No Internet connection');
    }
    return apiResponse;
    }

當我嘗試將文件發送到服務器時，我收到此錯誤

    Error: Unhandled error Expected a value of type 'String', but got one of type 'XFile' 
    occurred in Instance of 'BankTransferScreenBloc'.

我假設它與圖像的文件格式（XFile）有關。

Answer 1

在您選擇圖像的文件中，您應該訪問將返回字符串的 8mage 的路徑。 說你的變量是 selectedImage

final XFile? selectedImage = await ImagePicker.pickImage(source: ImageSource.gallery);
if(selectedImage!=null){
   slip = selectedImage.path;
}