Flutter - 如何下载视频并将它们保存到内部存储？

Question

我正在做一个 flutter 项目，我需要实现从服务器功能下载视频。我正在考虑使用 Dio 库并将下载的视频保存到 getApplicationDocumentsDirectory() 但我还没有找不到我想要实现的示例，我尝试了一些示例并尝试修改它们，但它没有用。任何人都知道如何管理它？谢谢 。

Answer 1

您可以在下面复制粘贴运行完整代码

代码片段

Future<void> downloadFile() async {
    Dio dio = Dio();

    try {
      var dir = await getApplicationDocumentsDirectory();
      print("path ${dir.path}");
      await dio.download(imgUrl, "${dir.path}/demo.mp4",
          onReceiveProgress: (rec, total) {
        print("Rec: $rec , Total: $total");

        setState(() {
          downloading = true;
          progressString = ((rec / total) * 100).toStringAsFixed(0) + "%";
        });
      });
    } catch (e) {
      print(e);
    }

    setState(() {
      downloading = false;
      progressString = "Completed";
    });
    print("Download completed");
  }

工作演示

输出

I/flutter (18244): path /data/user/0/yourdoamin.yourproject/app_flutter
I/flutter (18244): Rec: 2124 , Total: 2429896
I/flutter (18244): Rec: 4883 , Total: 2429896
...
I/flutter (18244): Rec: 2429896 , Total: 2429896
I/flutter (18244): Download completed

完整代码

import 'dart:async';

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

void main() => runApp(MaterialApp(
      home: MyApp(),
      debugShowCheckedModeBanner: false,
    ));

class MyApp extends StatefulWidget {
  @override
  MyAppState createState() {
    return new MyAppState();
  }
}

class MyAppState extends State<MyApp> {
  final imgUrl = "https://flutter.github.io/assets-for-api-docs/assets/videos/butterfly.mp4";
  bool downloading = false;
  var progressString = "";

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

    downloadFile();
  }

  Future<void> downloadFile() async {
    Dio dio = Dio();

    try {
      var dir = await getApplicationDocumentsDirectory();
      print("path ${dir.path}");
      await dio.download(imgUrl, "${dir.path}/demo.mp4",
          onReceiveProgress: (rec, total) {
        print("Rec: $rec , Total: $total");

        setState(() {
          downloading = true;
          progressString = ((rec / total) * 100).toStringAsFixed(0) + "%";
        });
      });
    } catch (e) {
      print(e);
    }

    setState(() {
      downloading = false;
      progressString = "Completed";
    });
    print("Download completed");
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("AppBar"),
      ),
      body: Center(
        child: downloading
            ? Container(
                height: 120.0,
                width: 200.0,
                child: Card(
                  color: Colors.black,
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: <Widget>[
                      CircularProgressIndicator(),
                      SizedBox(
                        height: 20.0,
                      ),
                      Text(
                        "Downloading File: $progressString",
                        style: TextStyle(
                          color: Colors.white,
                        ),
                      )
                    ],
                  ),
                ),
              )
            : Text("No Data"),
      ),
    );
  }
}