您可以复制粘贴运行下面的完整代码
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
output
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"),
),
);
}
}