如何下载附件在Flutter使用足够的邮件

Question

我需要从mime消息对象下载附件。下面，我已经添加了我的类文件。这是mime消息带来的。需要帮助提取附件并下载。

class EmailScreen extends StatefulWidget {
EmailScreen({
Key key,
this.mimeMessage,
this.userInfo
}) : super(key: key);
final MimeMessage mimeMessage;
final UserInfo userInfo;
@override
EmailScreenState createState() => EmailScreenState(
mimeMessage: mimeMessage,
userInfo: userInfo
);
}
class EmailScreenState extends State<EmailScreen> {
MimeMessage mimeMessage;
UserInfo userInfo;
EmailScreenState({Key key,this.mimeMessage,this.userInfo});
@override
Widget build(BuildContext context) {
throw UnimplementedError();
}

}

Answer 1

下面是我使用足够的邮件1.3.6下载附件的代码。

ListView.builder(
scrollDirection: Axis.horizontal,
itemCount: mimeMessage.findContentInfo().length,
itemBuilder: (context, index) {
ContentInfo contentInfo = mimeMessage
.findContentInfo()[index];
return Container(
padding: EdgeInsets.only(left: 10.0),
margin: EdgeInsets.only(right: 5.0),
decoration: BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.circular(10)
),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
SizedBox(
child: Text(
contentInfo.fileName,
overflow: TextOverflow.ellipsis,
)
),
IconButton(
onPressed: (){
setState(() {
MimePart mimePart = mimeMessage.getPart(contentInfo.fetchId);
Uint8List uint8List = mimePart.decodeContentBinary();

MySnackBar.show(
context,
MySnackBar.loadingIcon,
"Downloading....!"
);

saveFile(context,uint8List,contentInfo.fileName).then((value){
MySnackBar.hide(context);
if(value){
MySnackBar.show(
context,
MySnackBar.successIcon,
"Completed!"
);
}else{
MySnackBar.show(
context,
MySnackBar.errorIcon,
"Something went wrong!"
);
}
}).catchError((err){
MySnackBar.hide(context);
MySnackBar.show(
context,
MySnackBar.errorIcon,
"Something went wrong!"
);
});

});
},
icon: Icon(
Icons.download,
color: Colors.grey,
)
)
],
),
);
}
)

Future<bool> saveFile(BuildContext context,Uint8List uint8List, String fileName) async {
Directory directory;
try {
if (Platform.isAndroid) {
if (await requestPermission(Permission.storage)) {
directory = await getExternalStorageDirectory();
String newPath = "";
print(directory);
List<String> paths = directory.path.split("/");
for (int x = 1; x < paths.length; x++) {
String folder = paths[x];
if (folder != "Android") {
newPath += "/" + folder;
} else {
break;
}
}
newPath = newPath + "/NetxMail";
directory = Directory(newPath);
} else {
return false;
}
} else {
if (await requestPermission(Permission.photos)) {
directory = await getTemporaryDirectory();
} else {
return false;
}
}
if (!await directory.exists()) {
await directory.create(recursive: true);
}
if (await directory.exists()) {
File file = new File('${directory.path}/$fileName');
print("file path = ${file.path}");
await file.writeAsBytes(uint8List);
return true;
}
return false;
} catch (e) {
print(e);
return false;
}
}
Future<bool> requestPermission(Permission permission) async {
if (await permission.isGranted) {
return true;
} else {
var result = await permission.request();
if (result == PermissionStatus.granted) {
return true;
}
}
return false;
}