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downloads_path_provider —操作系统错误：权限被拒绝，错误号= 13

问题内容：

我用downloads_path_provider包写下载目录。我将其设置为推荐 <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />用于项目AndroidManifest.xml

但是当我尝试写时我得到这个错误 E/flutter (26091): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: FileSystemException: Cannot open file, path = '/storage/emulated/0/Download/secure-strorage-backup.txt' (OS Error: Permission denied, errno = 13)

这是代码

  final file = _localFile;
  file.writeAsString('1234  5678\n');
  file.writeAsString('1234  5678\n');

  File get _localFile {
    final path = _downloadsDirectory.path;
    return File('$path/secure-strorage-backup.txt');
  }

如何写入下载文件夹？

AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.user.myappname">
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <application
        android:name="io.flutter.app.FlutterApplication"
        android:label="Secure Storage"
        ...

这是我的下载方式

  void initState() {
    super.initState();
    initDownloadsDirectoryState();
  }

  Future<void> initDownloadsDirectoryState() async {
    Directory downloadsDirectory;
    try {
      downloadsDirectory = await DownloadsPathProvider.downloadsDirectory;
    } on PlatformException {
      print('Could not get the downloads directory');
    }
    if (!mounted) return;
    setState(() {
      _downloadsDirectory = downloadsDirectory;
    });
  }

问题答案：

如该答案中所述，您还需要明确询问您的用户使用外部存储的权限，您可以将该软件包用于

更新：

这个软件包变得更好，并且得分更高，您可以像这样使用它：

                  await Permission.storage.request();
                  Directory downloadsDirectory = await DownloadsPathProvider.downloadsDirectory;
                  final String path = downloadsDirectory.path;
                  final File file = File('$path/secure-strorage-backup.txt');
                  await file.writeAsString('1234  5678\n');
                  await file.writeAsString('1234  5678\n');
                  print(await file.readAsString());