如何从文件管理器 flutter 解析本地 json 文件？

Question

我看过很多从 assets

解析 json 文件的例子

但是如何从文件管理器获取 json 文件并解析它？

void openJsonFile() async {
    FilePickerResult? result = await FilePicker.platform.pickFiles();
    if (result != null) {
      File file = File(result.files.single.path!);
      if (file.path.contains('.json')) {
        parse(file);
      }
    } else {
      // User canceled the picker
    }
  }

  void parse(File file) async {
    final String response = await rootBundle.loadString(file.path);
    List<JsonItem> items = (jsonDecode(response) as List<dynamic>)
        .map((e) => JsonItem.fromJson(e))
        .toList();
    Navigator.of(dkey.currentState!.context).push(
      MaterialPageRoute(
          builder: (context) => JsonParsedListScreen(items: items)),
    );
  }


class JsonItem {
  int? id;
  String? name;

  JsonItem({this.id, this.name});

  factory JsonItem.fromJson(Map<String, dynamic> json) {
    return JsonItem(name: json['name'], id: json['id']);
  }
}


E/flutter (20466): [ERROR:flutter/lib/ui/ui_dart_state.cc(209)] Unhandled Exception: Unable to load asset: /data/user/0/com.example.play/cache/file_picker/sample.json
E/flutter (20466): #0      PlatformAssetBundle.load (package:flutter/src/services/asset_bundle.dart:237:7)
E/flutter (20466): <asynchronous suspension>
E/flutter (20466): #1      AssetBundle.loadString (package:flutter/src/services/asset_bundle.dart:72:27)
E/flutter (20466): <asynchronous suspension>
E/flutter (20466): #2      HomePage.parse (package:play/nextPage.dart:52:29)
E/flutter (20466): <asynchronous suspension>
E/flutter (20466):

我得到这个日志对于这一行 final String response = await rootBundle.loadString(file.path);

Answer 1

这是从 assets、

加载的

final String response = await rootBundle.loadString(file.path);

但是从文件中读取是这样的：

final response = await file.readAsString();

如何从文件管理器 flutter 解析本地 json 文件？

how do I parse the local json file from file manager flutter?

json

dart

flutter