flutter-template/lib/service/app_service.dart

import 'dart:io';

import 'package:ctjt_flutter/common/states.dart';
import 'package:ctjt_flutter/model/version_res.dart';
import 'package:ctjt_flutter/service/base_service.dart';
import 'package:dio/dio.dart';
import 'package:flutter/material.dart';
import 'package:path_provider/path_provider.dart';
import 'package:provider/provider.dart';

class AppService extends BaseService {
  late BuildContext mContext;

  AppService._();

  static final _instance = AppService._();

  factory AppService.getInstance(BuildContext context) {
    _instance.mContext = context;
    return _instance;
  }

  /// 拉取版本号信息
  Future<VersionResBody?> fetchVersionInfo(String v) async {
    int channelType = HTTPConfig.getChannelType(); // 根据环境判断更新渠道类型
    var uri = '/common/getAppVersion?currentVersion=' + v + '&channelType=' + channelType.toString();
    var data = await request(uri);
    if (null == data) {
      return null;
    }
    var ver = VersionRes.fromJson(data);
    print("Got version from remote:" + ver.body!.lastVersion!);
    return ver.body;
  }

  /// 下载安卓更新包
  Future<File?> downloadAndroid(String url, String version) async {
    /// 创建存储文件
    Directory? storageDir = await getExternalStorageDirectory();
    if (null == storageDir) {
      return null;
    }
    String storagePath = storageDir.path;
    File file = new File('$storagePath/ctjt_flutter_install_$version.apk');

    if (!file.existsSync()) {
      file.createSync();
    }

    /// 发起下载请求
    Response? response = await requestFile(url,
        onReceiveProgress: showDownloadProgress);
    if (null == response) {
      return null;
    }
    file.writeAsBytesSync(response.data);
    return file;
  }

  /// 展示下载进度
  void showDownloadProgress(num received, num total) {
    if (total != -1) {
      double _progress =
          double.parse('${(received / total).toStringAsFixed(2)}');
      print('Download process is $_progress');
      Provider.of<AppDownloadProcess>(mContext, listen: false).process =
          _progress;
    }
  }
}