Flutter: Unhandled Exception: Unable to load asset - flutter

Question

I am trying to build an app where one of the buttons should open a pdf. I used the guide in this link : https://pspdfkit.com/blog/2019/opening-a-pdf-in-flutter/ however it won't work on the first time the app is running it works only after a hot reload/restart. I have tried flutter clean. Also the output of the pubspec.yaml is exit code 0
flutter:
assets:
- PDFs/MyDoc.pdf
- assets/
Here is a snippet of the code:
import 'dart:io';
import 'dart:typed_data';
import 'package:flutter/material.dart';
import 'package:flutter_full_pdf_viewer/full_pdf_viewer_scaffold.dart';
import 'package:path_provider/path_provider.dart';
const String _documentPath = 'PDFs/MyDoc.pdf';
void main() => runApp(MaterialApp(
home: FadyCard(),
));
class FadyCard extends StatefulWidget {
#override
_FadyCardState createState() => _FadyCardState();
}
class _FadyCardState extends State<FadyCard> {
Future<String> prepareTestPdf() async {
final ByteData bytes =
await DefaultAssetBundle.of(context).load(_documentPath);
final Uint8List list = bytes.buffer.asUint8List();
final tempDir = await getTemporaryDirectory();
final tempDocumentPath = '${tempDir.path}/$_documentPath';
final file = await File(tempDocumentPath).create(recursive: true);
file.writeAsBytesSync(list);
return tempDocumentPath;
}
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.grey[900],
appBar: AppBar(
title: Text('Document'),
centerTitle: true,
backgroundColor: Colors.grey[850],
elevation: 0,
),
bottomNavigationBar: BottomAppBar(
shape: const CircularNotchedRectangle(),
child: Container(
height: 50.0,
),
color: Colors.grey[850],
),
floatingActionButton: FloatingActionButton(
onPressed: () => {
prepareTestPdf().then((path) {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => FullPdfViewerScreen(path)),
);
})
},
child: Icon(Icons.folder, color: Colors.amber,),
backgroundColor: Colors.grey[700],
),
floatingActionButtonLocation: FloatingActionButtonLocation.centerDocked,
);
}
}
class FullPdfViewerScreen extends StatelessWidget {
final String pdfPath;
FullPdfViewerScreen(this.pdfPath);
#override
Widget build(BuildContext context) {
return PDFViewerScaffold(
appBar: AppBar(
title: Text("My Document"),
backgroundColor: Colors.grey[800],
),
path: pdfPath);
}
}
Thanks in advance.

Answer 1

FadyCard is the StateFull Widget you need update the PDF inside the setState.
Try like this (not tested)
onPressed: () => {
setState(() {
prepareTestPdf().then((path) {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => FullPdfViewerScreen(path)),
);
})
})
}