Question

添加path_provider依赖项后，我遇到了某些类未定义的问题.``目录''和``文件''未定义，当我尝试在pubspec.yaml中为我的项目实现path_provider后出现了问题。按下图标按钮时，需要在文本文件中添加字符串。

进口：

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:cryptick/data/crypto_data.dart';
import 'package:cryptick/modules/crypto_presenter.dart';
import 'package:shimmer/shimmer.dart';
import 'dart:async';
import 'package:path_provider/path_provider.dart';

相关代码：

ListTile _getListItemUi(Crypto currency, MaterialColor color) {
    return new ListTile(
      leading: new Image.network("http://cryptoicons.co/32@2x/color/"+currency.symbol.toLowerCase()+"@2x.png"),
      title: new Text(currency.name,
          style: new TextStyle(fontWeight: FontWeight.bold)),
      subtitle:
      _getSubtitleText(currency.price_usd, currency.percent_change_1h),
      isThreeLine: true,
      trailing: new IconButton(
        icon: new Icon(Icons.add),
        onPressed: () async { Directory appDocDir = await getApplicationDocumentsDirectory();
        String appDocPath = appDocDir.path;
        new File('$appDocPath/my_file.txt').writeAsStringSync('myVar: $_currencies');  
        }
      ),
    );
  }

这两行显示错误：

onPressed: () async { Directory appDocDir = await getApplicationDocumentsDirectory();

并且：

new File('$appDocPath/my_file.txt').writeAsStringSync('myVar: $_currencies');

Answer 1

将其导入，您就可以开始：-

abc.properties

Flutter的'path_provider'依赖项中的未定义类

1 个答案: