基于advance_pdf_viewer和firebase_storage的颤振依赖问题

Question

当使用advance_pdf_viewer和firebase_storage包时，无法将应用程序复杂化。起初它的工作很好，但后来它的版本发生了变化，我不知道匹配的确切版本。

Publicspec.yaml文件

  cupertino_icons: ^1.0.3
  flutter_svg: ^0.22.0 # help us to use SVG in our app
  provider: ^5.0.0 # for State management
  getwidget: ^2.0.2
  shared_preferences: ^2.0.5
  firebase_auth: ^1.0.1
  firebase_core: ^1.0.2
  cloud_firestore: ^1.0.3
  firebase_storage: ^8.0.1
  advance_pdf_viewer:
  date_time_picker: ^2.0.0
  file_picker:
  intl: ^0.17.0
  path: ^1.8.0
  http:

错误消息

Running "flutter pub get" in appT...
Launching lib/main.dart on SDKPhone in debug mode...
Running Gradle task 'assembleDebug'...
Picked up _JAVA_OPTIONS: -Dawt.useSystemAAFontSettings=on -Dswing.aatext=true
../../flutter/.pub-cache/hosted/pub.dartlang.org/advance_pdf_viewer-2.0.0/lib/src/document.dart:64:14: Error: The class 'File' is abstract and can't be instantiated.
      file = File("${dir.path}/file.pdf");
             ^^^^
../../flutter/.pub-cache/hosted/pub.dartlang.org/advance_pdf_viewer-2.0.0/lib/src/document.dart:72:26: Error: Non-nullable variable 'file' must be assigned before it can be used.
    document._filePath = file.path;
                         ^^^^
../../flutter/.pub-cache/hosted/pub.dartlang.org/advance_pdf_viewer-2.0.0/lib/src/document.dart:75:58: Error: Non-nullable variable 'file' must be assigned before it can be used.
          .invokeMethod('getNumberOfPages', {'filePath': file.path});
                                                         ^^^^


FAILURE: Build failed with an exception.

* Where:
Script '/home/flutter/packages/flutter_tools/gradle/flutter.gradle' line: 1035

* What went wrong:
Execution failed for task ':app:compileFlutterBuildDebug'.
> Process 'command '/home/flutter/bin/flutter'' finished with non-zero exit value 1

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 48s
Exception: Gradle task assembleDebug failed with exit code 1

Answer 1

#这很管用

以详细的方式从上面的链接答案。

编辑/flutter/.pub-cache/hosted/pub.dartlang.org/advance_pdf_viewer-2.0.0/lib/src/document.dart

//edit the import line like this
//import 'dart:io'; - > import 'dart:io' as io; : line 2
import 'dart:io' as io;
....
....
....

static Future fromAsset(String asset) async {
    io.File file; // Edited
    try {
        var dir = await getApplicationDocumentsDirectory();
        file = io.File("${dir.path}/file.pdf"); // Edited
        var data = await rootBundle.load(asset);
        var bytes = data.buffer.asUint8List();
        await file.writeAsBytes(bytes, flush: true);
    } catch (e) {
        throw Exception('Error parsing asset file!');
    }
    PDFDocument document = PDFDocument();
    document._filePath = file.path;
    try {
        var pageCount = await _channel
        .invokeMethod('getNumberOfPages', {'filePath': file.path});
        document.count = document.count = int.parse(pageCount);
    } catch (e) {
        throw Exception('Error reading PDF!');
    }
    return document;
}

解决方案：

将包导入为"io“，并只在"fromAsset”函数中更改，将类(文件)调用为"io.File“，这样它就能正常工作。