我的 Pdf 文档没有下载或打开，因为图像文件在 flutter 下载后打开

Question

我的 Pdf 文档无法下载或打开，而图像文件在 flutter 中下载后打开。

我已经使用文件选择器选择图像文件和 pdf 文件并将它们发送到 firebase 存储。

我的图像文件正在下载和打开，但在将它发送到 firebase 存储后无法下载 PDF 文件。

可能是正在下载，但是点击下载按钮无法查看

   Future<void> downloadFile(StorageReference ref) async {
    final String url = await ref.getDownloadURL();
    final http.Response downloadData = await http.get(url);
    final Directory systemTempDir = Directory.systemTemp;
    final File tempFile = File('${systemTempDir.path}/tmp.jpg');
    if (tempFile.existsSync()) {
      await tempFile.delete();
    }
    await tempFile.create();
    final StorageFileDownloadTask task = ref.writeToFile(tempFile);
    final int byteCount = (await task.future).totalByteCount;
    var bodyBytes = downloadData.bodyBytes;
    final String name = await ref.getName();
    final String path = await ref.getPath();
    print(
      'Success!\nDownloaded $name \nUrl: $url'
          '\npath: $path \nBytes Count :: $byteCount',
    );
    _scaffoldKey.currentState.showSnackBar(
      SnackBar(
        backgroundColor: Colors.white,
        content: Image.memory(
          bodyBytes,
          fit: BoxFit.fill,
        ),
      ),
    );
  }
}``

如果以上代码或任何地方需要任何更改，请建议我

Answer 1

Flutter默认支持打开图片，打开pdf需要使用pdf插件（依赖）。 https://codecarbon.com/top-pdf-widgets-for-flutter/ 完成这个 link，我认为 7。 pdf_viewer_plugin 适合这个应用。

Dependencies:
flutter_full_pdf_viewer: ^1.0.6 # MIT  Licence

创建一个新文件 display-pdf.dart 并在其中添加以下代码。

import 'package:flutter/material.dart';
import 'package:flutter_full_pdf_viewer/full_pdf_viewer_scaffold.dart';

class DisplayPDF extends StatelessWidget {
  final String pdfPath;
  final String title;

  DisplayPDF(this.pdfPath, this.title);

  @override
  Widget build(BuildContext context) {
    return PDFViewerScaffold(
        appBar: AppBar(
          title: Text(title),
          centerTitle: true,
        ),
        path: pdfPath);
  }
}

创建一个文件 pdf-utilities.dart 并在其中添加以下代码。


import 'dart:async';
import 'dart:typed_data';
import 'dart:io';
import 'package:flutter/material.dart';
import 'package:path_provider/path_provider.dart';

class PdfUtilities {
  final String pdfPath;
  final BuildContext context;

  PdfUtilities(this.pdfPath, this.context);

  Future<String> prepareTestPdf() async {
    final ByteData bytes = await DefaultAssetBundle.of(context).load(pdfPath);
    final Uint8List list = bytes.buffer.asUint8List();

    final tempDir = await getTemporaryDirectory();
    final tempDocumentPath = '${tempDir.path}/$pdfPath';

    final file = await File(tempDocumentPath).create(recursive: true);
    file.writeAsBytesSync(list);
    return tempDocumentPath;
  }
}

将 Future<void> downloadFile(StorageReference ref) async 替换为此代码：

Future<void> downloadFile(StorageReference ref) async {
  final String url = await ref.getDownloadURL();
  final http.Response downloadFile = await http.get(url);
  final Directory systemTempDir = Directory.systemTemp;
  final File tempFile = File('${systemTempDir.path}/tmp.pdf');
  if (tempFile.existsSync()) {
    await tempFile.delete();
  }
  await tempFile.create();
  final StorageFileDownloadTask task = ref.writeToFile(tempFile);
  final int byteCount = (await task.future).totalByteCount;
  var bodyBytes = downloadFile.bodyBytes;
  final String name = await ref.getName();  
  final String path = await ref.getPath();
  print(
    'Success!\nDownloaded $name \nUrl: $url'
        '\npath: $path \nBytes Count :: $byteCount',
  );
  final String title = 'Displaying PDF';
  PdfUtilities pdf = new PdfUtilities(path, context);
  pdf.prepareTestPdf().then(writeCounter(await bodyBytes),
        (path) {
      Navigator.push(
        context,
        MaterialPageRoute(
          builder: (context) => DisplayPDF(path, title),
        ),
      );
    },
  );
}
Future<File> writeCounter(Uint8List stream) async {
  final file = await _localFile;

  // Write the file
  return file.writeAsBytes(stream);
}

我的 Pdf 文档没有下载或打开，因为图像文件在 flutter 下载后打开

My Pdf document is not downloading or opening where as image file is opening after download in flutter

pdf

storage

download

firebase

flutter