Question

您好，我想使用flutter_downloader包下载文件，我尝试使用示例中的代码关于文档的问题，我有时会出现黑屏，有时会出现白屏，但我不知道为什么我只尝试使用示例函数中的一个函数，但我却报错并且无法正常工作

 import 'dart:isolate';
import 'dart:ui';

import 'package:flutter/material.dart';
import 'dart:async';
import 'package:path_provider/path_provider.dart';
import 'package:flutter_downloader/flutter_downloader.dart';
import 'package:permission_handler/permission_handler.dart';
import 'dart:io';

const debug = true;


class download extends StatefulWidget with WidgetsBindingObserver {
  final TargetPlatform platform;

  download({Key key, this.title, this.platform}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

class _MyHomePageState extends State<download> {



  String _localPath;

  @override
  void initState() {
    super.initState();


   WidgetsFlutterBinding.ensureInitialized();
   FlutterDownloader.initialize(
       debug: true // optional: set false to disable printing logs to console
   );
 
  }

  @override
  void dispose() {
    super.dispose();
  }


  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text('bonjour'),
      ),
    body:FlatButton(
    child:Text('bbbbb'),
    onPressed: _requestDownload,
    )
    );
  }



  void _requestDownload() async {
     await FlutterDownloader.enqueue(
        url:'http://barbra-coco.dyndns.org/student/learning_android_studio.pdf' ,
        headers: {"auth": "test_for_sql_encoding"},
        savedDir: _localPath,
        showNotification: true,
        openFileFromNotification: true);
  }

我有这个例外

[ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: 'package:flutter_downloader/src/downloader.dart': Failed assertion: line 73 pos 12: '_initialized': FlutterDownloader.initialize() must be called first

我在问是否有一个例证或解决方案，或者一个有例证和细节的有效例子谢谢您

Answer 1

根据错误提示以及使用前必须初始化的文档，

称呼这个

WidgetsFlutterBinding.ensureInitialized();
FlutterDownloader.initialize(
  debug: true // optional: set false to disable printing logs to console
);

并在下面的AndroidManifest中添加此代码

<provider
    android:name="vn.hunghd.flutterdownloader.DownloadedFileProvider"
    android:authorities="${applicationId}.flutter_downloader.provider"
    android:exported="false"
    android:grantUriPermissions="true">
    <meta-data
        android:name="android.support.FILE_PROVIDER_PATHS"
        android:resource="@xml/provider_paths"/>
</provider>

检查documentation了解更多

Flutter如何使用flutter_downloader软件包下载文件

1 个答案: