从 flutter 中的 Firebase Firestore 集合创建一个 PDF 文件

Question

I have various collections in Firestore,I want to create a button which saves the data fetched from specific collection into a PDF file. I don't know how to use PDF package for saving the data fetched via query into a PDF file.

I have a demo code which fetch data from Firestore collection and show it in list view, now I want to create a button over there which will allow the user to download that fetched data into a PDF and save that PDF to device.

below is the code which shows list view of data fetched from that collection

 Container buildUserPosts() {
  Future<List<NewsPost>> getPosts() async {
    List<NewsPost> posts = [];
    var snap = await FirebaseFirestore.instance
        .collection('News')
        .orderBy("timestamp")
        .get();

    for (var doc in snap.docs) {
       posts.add(NewsPost.fromDocument(doc));
    }

    return posts.reversed.toList();
  }
  return Container(
      child: FutureBuilder<List<NewsPost>>(
    future: getPosts(),
    builder: (context, snapshot) {
      if (!snapshot.hasData) {
        return Container(
            alignment: FractionalOffset.center,
            padding: const EdgeInsets.only(top: 10.0),
            child: CircularProgressIndicator());
      } else {
        return Column(
            children: snapshot.data!.map((NewsPost imagePost) {
          return imagePost;
        }).toList());
      }
    },
  ));

Now I want this data to be saved in a PDF but unable to figure how to achieve it. Please suggest how it can be done?

Answer 1

You need to use the packages widgets to build generate the pdf

import 'dart:io';

import 'package:pdf/widgets.dart' as pw;

Future<void> generatePdf(MyData? mydata) async {
  final pdf = pw.Document();
// build your pdf view here
  pdf.addPage(
    pw.Page(
      build: (pw.Context context) => pw.Center(
        child: pw.Text(mydata?.title ??''),
      ),
    ),
  );
//save pdf
  final file = File('example.pdf');
  await file.writeAsBytes(await pdf.save());
}