zhiying_comm/lib/util/download/download.dart

import 'dart:collection';
import 'dart:io';

import 'package:dio/dio.dart';
import 'package:flutter/material.dart';
import 'package:fluttertoast/fluttertoast.dart';
import 'package:path_provider/path_provider.dart';
import 'package:permission_handler/permission_handler.dart';
import 'package:save_image/save_image.dart';

class Download {
  static HashMap hashMap = HashMap();

  Future<String> fileToGallery(
    String url, {
    String postfix,
    Function(int, int) progress,
  }) async {
    // 检查是否已有读写内存的权限
    bool status = await Permission.storage.isGranted;

    //判断如果还没拥有读写权限就申请获取权限
    if (status || await Permission.storage.request().isGranted) {
      if (hashMap.containsKey(url)) {
        return "正在下载";
      } else {
        hashMap[url] = false;
      }
      try {
        var strs = url.split('.');
        if (strs.length < 0) {
          return "文件链接错误";
        }
        var appDocDir = await getTemporaryDirectory();
        String savePath = appDocDir.path +
            "/" +
            DateTime.now().toIso8601String().toString() +
            (strs[strs.length - 1].length > 4 ? (postfix ?? "") : ('.' + strs[strs.length - 1]));
        await Dio().download(url, savePath, onReceiveProgress: (count, toal) {
          if (progress != null) {
            progress(count, toal);
          }
        });
        print(savePath);
        var result = await SaveImage.save(imageBytes: File(savePath).readAsBytesSync());
        if (result != null && result) {
          return "保存成功";
        } else {
          return "保存失败";
        }
      } catch (e) {
        return "下载失败,原因:" + e.toString();
      } finally {
        hashMap.remove(url);
      }
    } else {
      return "请前往系统设置开启应用的内存读取权限再尝试";
    }
  }
}