flutter上傳圖檔到華為雲obs

import 'dart:io';

import 'package:dio/dio.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter_screenutil/screenutil.dart';
import 'package:image_pickers/Media.dart';
import 'package:oktoast/oktoast.dart';
import 'package:visitormachine/widget/load_image.dart';
import 'package:visitormachine/widget/my_app_bar.dart';
import 'package:image_pickers/image_pickers.dart';
import 'package:http_parser/http_parser.dart';
import 'package:crypto/crypto.dart';
///這裡用來進行Base64編碼，UTF-8編碼的
import 'dart:convert';
///這裡用來擷取檔案file的檔案名稱的
import 'package:path/path.dart';
///HMAC-SHA1加密用的（這個是第三方庫需要依賴）
import 'package:crypto/crypto.dart';


class TrainPhotographPage extends StatefulWidget {
  TrainPhotographPage({Key key}) : super(key: key);

  @override
  _TrainPhotographP