如何在Flutter中突出显示特定字母的文本？

Question

我试图突出显示两个字母“Rs”，任何特殊字符，如“% 或 !” 以及 1234 等数字。

我已经从这个问题中得到了一半的答案 -如何在 Flutter 中突出显示文本？ 但我不知道如何编辑字母，因为我是正则表达式的新手？

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

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

class _MyHomePageState extends State<MyHomePage> {
  String str = "Hey I'm 1234 and %";
  int findLen(String word) {
    return word.replaceAll(new RegExp(r'[a-zA-Z]'), "").length;
  }

  var styleOne = TextStyle(color: Colors.black87, fontSize: 21);

  var styleTwo = TextStyle(
      color: Colors.black87, fontWeight: FontWeight.w800, fontSize: 24);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: RichText(
        overflow: TextOverflow.ellipsis,
        textAlign: TextAlign.center,
        maxLines: 4,
        text: TextSpan(
          children: str
              .split(" ")
              .map((word) => TextSpan(
                  text: word + " ",
                  style: findLen(word) != word.length ? styleOne : styleTwo))
              .toList(),
        ),
      ),
    );
  }
} 

Answer 1

你可以尝试这样的事情：

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

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

class _MyHomePageState extends State<MyHomePage> {
  String str = "Hey I'm 1234 and % Rs10";
  int findLen(String word) {
    return word.replaceAll(new RegExp(r'[a-zA-Z]'), "").length;
  }

  var styleOne = TextStyle(color: Colors.black87, fontSize: 21);

  var styleTwo = TextStyle(
      color: Colors.black87, fontWeight: FontWeight.w800, fontSize: 24);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: RichText(
        overflow: TextOverflow.ellipsis,
        textAlign: TextAlign.center,
        maxLines: 4,
        text: TextSpan(
          children: str
              .split(" ")
              .map((word) => TextSpan(
                  text: word + " ",
                  style: findLen(word) == word.length ||
                          word.substring(0, 2).contains("Rs")
                      ? styleTwo
                      : styleOne))
              .toList(),
        ),
      ),
    );
  }
}

工作演示：Codepen