Android 如何使用颤振dio下载文件?
我想在flatterAndroid 如何使用颤振dio下载文件?,android,ios,http,flutter,dart,Android,Ios,Http,Flutter,Dart,我想在flatterDio的帮助下使用url下载文件 final imgUrl = "https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf"; var dio = Dio(); 未来下载2(Dio Dio、字符串url、字符串保存路径)异步{ 试一试{ 响应=等待dio.get( 网址, onReceiveProgress:显示下载进度, //接收到的带有列表的数据 选项:选项( response
Dio
的帮助下使用url下载文件
final imgUrl = "https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf";
var dio = Dio();
未来下载2(Dio Dio、字符串url、字符串保存路径)异步{
试一试{
响应=等待dio.get(
网址,
onReceiveProgress:显示下载进度,
//接收到的带有列表的数据
选项:选项(
responseType:responseType.bytes,
followRedirects:false,
validateStatus:(状态){返回状态<500;}
),
);
打印(响应.标题);
文件=文件(保存路径);
var raf=file.openSync(模式:FileMode.write);
//response.data是列表类型
raf.writeFromSync(response.data);
等待皇家空军关闭();
}捕获(e){
印刷品(e);
}
}
作废显示下载进度(已收到,总计){
如果(总计!=-1){
打印((已接收/总计*100)。ToStringGasFixed(0)+“%”);
}
}
我发现了这个错误
操作系统错误:权限被拒绝,errno=13flatter您可以复制下面的粘贴运行完整代码
您需要使用获取临时目录
代码片段
RaisedButton.icon(
onPressed: () async {
var tempDir = await getTemporaryDirectory();
String fullPath = tempDir.path + "/boo2.pdf'";
print('full path ${fullPath}');
download2(dio, imgUrl, fullPath);
},
icon: Icon(
Icons.file_download,
color: Colors.white,
),
color: Colors.green,
textColor: Colors.white,
label: Text('Dowload Invoice'))
工作演示
完整代码
import 'package:flutter/material.dart';
import 'package:dio/dio.dart';
import 'package:path_provider/path_provider.dart';
import 'dart:io';
final imgUrl =
"https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf";
var dio = Dio();
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
setState(() {
_counter++;
});
}
Future download2(Dio dio, String url, String savePath) async {
try {
Response response = await dio.get(
url,
onReceiveProgress: showDownloadProgress,
//Received data with List<int>
options: Options(
responseType: ResponseType.bytes,
followRedirects: false,
validateStatus: (status) {
return status < 500;
}),
);
print(response.headers);
File file = File(savePath);
var raf = file.openSync(mode: FileMode.write);
// response.data is List<int> type
raf.writeFromSync(response.data);
await raf.close();
} catch (e) {
print(e);
}
}
void showDownloadProgress(received, total) {
if (total != -1) {
print((received / total * 100).toStringAsFixed(0) + "%");
}
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
RaisedButton.icon(
onPressed: () async {
var tempDir = await getTemporaryDirectory();
String fullPath = tempDir.path + "/boo2.pdf'";
print('full path ${fullPath}');
download2(dio, imgUrl, fullPath);
},
icon: Icon(
Icons.file_download,
color: Colors.white,
),
color: Colors.green,
textColor: Colors.white,
label: Text('Dowload Invoice')),
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.display1,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}
导入“包装:颤振/材料.省道”;
进口“包装:dio/dio.dart”;
导入“package:path_provider/path_provider.dart”;
导入“dart:io”;
最终图像=
"https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf";
var-dio=dio();
void main()=>runApp(MyApp());
类MyApp扩展了无状态小部件{
@凌驾
小部件构建(构建上下文){
返回材料PP(
标题:“颤振演示”,
主题:主题数据(
主样本:颜色。蓝色,
),
主页:MyHomePage(标题:“颤振演示主页”),
);
}
}
类MyHomePage扩展StatefulWidget{
MyHomePage({Key,this.title}):超级(Key:Key);
最后的字符串标题;
@凌驾
_MyHomePageState createState()=>\u MyHomePageState();
}
类_MyHomePageState扩展状态{
int _计数器=0;
void _incrementCounter(){
设置状态(){
_计数器++;
});
}
未来下载2(Dio Dio、字符串url、字符串保存路径)异步{
试一试{
响应=等待dio.get(
网址,
onReceiveProgress:显示下载进度,
//接收到的带有列表的数据
选项:选项(
responseType:responseType.bytes,
followRedirects:false,
验证状态:(状态){
返回状态<500;
}),
);
打印(响应.标题);
文件=文件(保存路径);
var raf=file.openSync(模式:FileMode.write);
//response.data是列表类型
raf.writeFromSync(response.data);
等待皇家空军关闭();
}捕获(e){
印刷品(e);
}
}
作废显示下载进度(已收到,总计){
如果(总计!=-1){
打印((已接收/总计*100)。ToStringGasFixed(0)+“%”);
}
}
@凌驾
小部件构建(构建上下文){
返回脚手架(
appBar:appBar(
标题:文本(widget.title),
),
正文:中(
子:列(
mainAxisAlignment:mainAxisAlignment.center,
儿童:[
RaisedButton.icon(
onPressed:()异步{
var tempDir=await getTemporaryDirectory();
字符串fullPath=tempDir.path+“/boo2.pdf';
打印('full path${fullPath}');
下载2(dio、imgUrl、fullPath);
},
图标:图标(
Icons.file_下载,
颜色:颜色,白色,
),
颜色:颜色。绿色,
textColor:Colors.white,
标签:文本(“Dowload发票”),
正文(
“您已经按了这么多次按钮:”,
),
正文(
“$”计数器“,
样式:Theme.of(context).textTheme.display1,
),
],
),
),
浮动操作按钮:浮动操作按钮(
按下时:\ u递增计数器,
工具提示:“增量”,
子:图标(Icons.add),
),
);
}
}
您必须添加权限
对于Android:在AndroidManifest.xml中
如果我想将此文件存储在我的下载文件夹中,我如何给出路径?表示我要存储下载文件的任何特定位置。您不能执行任何文件夹操作,Android较新版本中的大多数文件夹都受到保护。您可以在getTemporaryDirectory()中创建文件夹,但下载的文件不会显示在我的手机中。如果您不授予写入外部存储的权限,则会发生错误
RaisedButton.icon(
onPressed: () async {
var tempDir = await getTemporaryDirectory();
String fullPath = tempDir.path + "/boo2.pdf'";
print('full path ${fullPath}');
download2(dio, imgUrl, fullPath);
},
icon: Icon(
Icons.file_download,
color: Colors.white,
),
color: Colors.green,
textColor: Colors.white,
label: Text('Dowload Invoice'))
import 'package:flutter/material.dart';
import 'package:dio/dio.dart';
import 'package:path_provider/path_provider.dart';
import 'dart:io';
final imgUrl =
"https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf";
var dio = Dio();
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
setState(() {
_counter++;
});
}
Future download2(Dio dio, String url, String savePath) async {
try {
Response response = await dio.get(
url,
onReceiveProgress: showDownloadProgress,
//Received data with List<int>
options: Options(
responseType: ResponseType.bytes,
followRedirects: false,
validateStatus: (status) {
return status < 500;
}),
);
print(response.headers);
File file = File(savePath);
var raf = file.openSync(mode: FileMode.write);
// response.data is List<int> type
raf.writeFromSync(response.data);
await raf.close();
} catch (e) {
print(e);
}
}
void showDownloadProgress(received, total) {
if (total != -1) {
print((received / total * 100).toStringAsFixed(0) + "%");
}
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
RaisedButton.icon(
onPressed: () async {
var tempDir = await getTemporaryDirectory();
String fullPath = tempDir.path + "/boo2.pdf'";
print('full path ${fullPath}');
download2(dio, imgUrl, fullPath);
},
icon: Icon(
Icons.file_download,
color: Colors.white,
),
color: Colors.green,
textColor: Colors.white,
label: Text('Dowload Invoice')),
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.display1,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}
<manifest...
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.INTERNET"/>
@override
void initState() {
getPermission();
super.initState();
}
//get storage permission
void getPermission() async {
await PermissionHandler().requestPermissions([PermissionGroup.storage]);
}