Flutter Dio : How to Upload Image?

Question

我正在尝试 postman 。它有效

我想使用 Package 将一些图像上传到 rest-api DIO 封装 ,
我是这个包的新手(我只是将这个包用于 CRUD 操作)，上传图片操作时遇到问题。
我已经在阅读文档，但没有看到上传图片。我正在尝试此代码(引用文档)并遇到一些错误:

error:FileSystemException
message :"Cannot retrieve length of file"
OSError (OS Error: No such file or directory, errno = 2)
"File: '/storage/emulated/0/Android/data/com.example.mosque/files/Pictures/scaled_IMG_20190815_183541.jpg'"
Type (FileSystemException)
message:FileSystemException: Cannot retrieve length of file, path = 'File: '/storage/emulated/0/Android/data/com.example.mosque/files/Pictures/scaled_IMG_20190815_183541.jpg'' (OS Error: No such file or directory, errno = 2)
DioErrorType (DioErrorType.DEFAULT)
name:"DioErrorType.DEFAULT"

Dart

Future uploadImage({dynamic data,Options options}) async{
      Response apiRespon =  await dio.post('$baseURL/mahasiswa/upload/',data: data,options: options);
      if(apiRespon.statusCode== 201){
        return apiRespon.statusCode==201;
      }else{
        print('errr');
        return null;
      }
}

查看.dart

void uploadImage() async {
    FormData formData = FormData.from({
      "name_image": _txtNameImage.text,
      "image": UploadFileInfo(File("$_image"), "image.jpg")
    });
    bool upload =
        await api.uploadImage(data: formData, options: CrudComponent.options);
    upload ? print('success') : print('fail');
  }

_image is type FILE

我希望这个包的专家可以帮助我处理这个代码并建议我上传图片。
谢谢。
完整的 View.dart 代码

import 'dart:io';

import 'package:dio/dio.dart';
import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
import 'package:mosque/api/api_mosque.dart';

class UploadImage extends StatefulWidget {
  @override
  _UploadImageState createState() => _UploadImageState();
}

class _UploadImageState extends State<UploadImage> {
  ApiHelper api = ApiHelper();
  File _image;
  TextEditingController _txtNameImage = TextEditingController();
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        leading: IconButton(
          icon: Icon(Icons.arrow_left),
          onPressed: () => Navigator.pop(context, false),
        ),
        actions: <Widget>[
          IconButton(
            icon: Icon(Icons.file_upload),
            onPressed: () {
              uploadImage();
            },
          )
        ],
      ),
      body: _formUpload(),
    );
  }

  Widget _formUpload() {
    return SingleChildScrollView(
      scrollDirection: Axis.vertical,
      child: Column(
        children: <Widget>[
          TextField(
            controller: _txtNameImage,
            keyboardType: TextInputType.text,
            decoration: InputDecoration(hintText: "Nama Image"),
            maxLength: 9,
            textAlign: TextAlign.center,
          ),
          SizedBox(
            height: 50.0,
          ),
          Container(
            child: _image == null
                ? Text('No Images Selected')
                : Image.file(_image),
          ),
          SizedBox(
            height: 50.0,
          ),
          Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              RaisedButton(
                child: Icon(Icons.camera),
                onPressed: () => getImageCamera(),
              ),
              SizedBox(
                width: 50.0,
              ),
              RaisedButton(
                child: Icon(Icons.image),
                onPressed: () => getImageGallery(),
              )
            ],
          )
        ],
      ),
    );
  }

  void uploadImage() async {
    FormData formData = FormData.from({
      "name_image": _txtNameImage.text,
      "image": UploadFileInfo(File("$_image"), "image.jpg")
    });
    bool upload =
        await api.uploadImage(data: formData, options: CrudComponent.options);
    upload ? print('success') : print('fail');
  }

  getImageGallery() async {
    var imageFile = await ImagePicker.pickImage(source: ImageSource.gallery);
    setState(() {
      _image = imageFile;
    });
  }

  getImageCamera() async {
    var imageFile = await ImagePicker.pickImage(source: ImageSource.camera);
    setState(() {
      _image = imageFile;
    });
  }
}

Answer 1

在 迪奥最新版 , UploadFileInfo方法已被 MultipartFile 取代类(class)。这里是如何使用发布图像、视频或任何文件的方式:

Future<String> uploadImage(File file) async {
    String fileName = file.path.split('/').last;
    FormData formData = FormData.fromMap({
        "file":
            await MultipartFile.fromFile(file.path, filename:fileName),
    });
    response = await dio.post("/info", data: formData);
    return response.data['id'];
}