Question

我正在尝试使用GoogleTranslator库翻译输入文本，但出现一个错误，提示String类型不是Widget类型的子类型

我试图创建一个接收文本并返回翻译后的文本并使用应用程序主体上的小部件的函数

import 'package:flutter/material.dart';
import 'package:translator/translator.dart';

void main() => runApp(MyApp());

Widget translator(String input) {
  GoogleTranslator translator = GoogleTranslator();

  String translation = translator
      .translate("I would buy a car, if I had money.", from: 'en', to: 'ar')
      .toString();
  return translation as Widget;
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Translator'),
        ),
        body: Center(
          child: translator("Hello World"),
        ),
      ),
    );
  }
}

我希望输出内容是屏幕中央的翻译文本

Answer 1

return translation as Widget;

应该是

return Text(translation);

更新

import 'package:flutter/material.dart';
import 'package:translator/translator.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Translator'),
        ),
        body: Center(
          child: MyHomePage(),
        ),
      ),
    );
  }
}

class MyHomePage extends StatefulWidget {

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final _translations = <String,String>{};

  String translator(String input) {
    if(_translations.containsKey(input)) {
      return _translations[input];
    } else {
      _translate(input);
      return input;
    }
  }

  Future<void> _translate(String input) async { 
    GoogleTranslator translator = GoogleTranslator();

    String translation = await translator
        .translate("I would buy a car, if I had money.", from: 'en', to: 'ar');
    setState(() => _translations[input] = translation);
  }

  @override
  Widget build(BuildContext context) {
    return Text(translator("Hello World"));
  }
}

如何修复“字符串不是小部件类型的子类型”？

1 个答案: