如何从flutter中的资产文件夹中下载PDF文件（直接）

Question

资产目录的屏幕截图

在此处输入图像描述

Answer 1

要在 Web 和移动设备（Android 和 iOS）的 Flutter 应用程序中下载资源 PDF

对于 Web：

import 'dart:typed_data';
import 'package:flutter/services.dart' show rootBundle;
import 'package:universal_html/html.dart' as html;

void downloadPdfWeb() async {
  final ByteData bytes = await rootBundle.load('assets/sample.pdf');
  final Uint8List list = bytes.buffer.asUint8List();
  final blob = html.Blob([list], 'application/pdf');
  final url = html.Url.createObjectUrlFromBlob(blob);
  final anchor = html.AnchorElement(href: url)
    ..setAttribute('download', 'sample.pdf')
    ..click();
  html.Url.revokeObjectUrl(url);
}

对于 Android 和 iOS iOS：

import 'dart:io';
import 'dart:typed_data';
import 'package:flutter/services.dart' show rootBundle;
import 'package:path_provider/path_provider.dart';

void downloadPdfMobile() async {
  try {
    final ByteData bytes = await rootBundle.load('assets/sample.pdf');
    final Uint8List list = bytes.buffer.asUint8List();
    final directory = await getExternalStorageDirectory();
    final file = File('${directory?.path}/sample.pdf');
    await file.writeAsBytes(list);
    print('PDF Downloaded to ${file.path}');
  } catch (e) {
    print('Error downloading PDF: $e');
  }
}

Answer 2

试试看，

import 'dart:html' as html;

downloadFile(url) {
  html.AnchorElement(href: url)
  ..download = "your_file_name.pdf" // Specify the filename
  ..click();
}

只需确保您在此处通过正确的资产URL即可。