Displaying text with Emojis on Flutter

问题

I have some texts that contain emojis and I'm trying to show them on the Text widget. However, they seem to be shown as foreign characters. Does Flutter support showing emojis? should work for both iOS and Android

回答1:

Flutter supports emoji. Here's some code that demonstrates emoji text entry. (If you're seeing foreign characters, it's likely that you're decoding bytes as ASCII instead of UTF-8; we can show you how to fix this if you update your question with code that demonstrates the problem.)

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

void main() {
  runApp(new MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Flutter Demo',
      home: new MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key}) : super(key: key);

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

class _MyHomePageState extends State<MyHomePage> {
  String _message = '🐣';

  Future<String> _promptForString(String label, { String hintText }) {
    final TextEditingController controller = new TextEditingController();
    return showDialog(
      context: context,
      child: new AlertDialog(
        title: new Text(label),
        content: new TextFormField(
          controller: controller,
          decoration: new InputDecoration(hintText: hintText),
        ),
        actions: <Widget>[
          new FlatButton(
            onPressed: () => Navigator.pop(context),
            child: const Text('CANCEL'),
          ),
          new FlatButton(
            onPressed: () => Navigator.pop(context, controller.text),
            child: const Text('OK'),
          ),
        ],
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text(_message),
      ),
      body: new Center(
        child: new Text(_message, style: Theme.of(context).textTheme.display2),
      ),
      floatingActionButton: new FloatingActionButton(
        child: new Icon(Icons.edit),
        onPressed: () async {
          String message = await _promptForString('New text', hintText: 'Try emoji!');
          if (!mounted)
            return;
          setState(() {
            _message = message;
          });
        },
      ),
    );
  }
}

回答2:

If you just want to include emoji in Text widget, you can copy emoji from somewhere else and paste it inside the text widget. I use GeteMoji to copy emojis.

See the Output Screenshot

CODE : See 8th Row.

Widget build(BuildContext context) {
    return Center(
        child: Container(
            alignment: Alignment.center,
            color: Colors.deepPurple,
            //width: 200.0,
            //height: 100.0,
            child: Text("Emoji 🤣 ",
                style: TextStyle(
                  fontFamily: 'Raleway',
                  fontSize: 40,
                  decoration: TextDecoration.none,
                  color: Colors.white

                ))));
  }

回答3:

The Problem

As of now, unfortunately, Flutter uses the default Emojis supported on a given platform. Therefore, when building a cross-platform app you may face issues of Emojis showing on certain devices and not on others.

The Solution

The solution I settled for is to use a custom Emoji font such as Emoji One and RichText widget instead of the basic Text widget.

With this, you can simply have:

RichText(
  text: TextSpan(
    children: <TextSpan>[
      TextSpan(
        text: 'Hello',  // non-emoji characters
      ),
      TextSpan(
        text: '🧭 🏳️\u200d🌈', // emoji characters
        style: TextStyle(
          fontFamily: 'EmojiOne',
        ),
      ),
    ],
  ),
);

Generalized Solution

With this idea, we can even create a custom widget that given a string, builds a RichText object with all the TextSpans autocreated:

class EmojiText extends StatelessWidget {

  const EmojiText({
    Key key,
    @required this.text,
  }) : assert(text != null),
       super(key: key);

  final String text;

  @override
  Widget build(BuildContext context) {
    return RichText(
      text: _buildText(this.text),
    );
  }

  TextSpan _buildText(String text) {
    final children = <TextSpan>[]; 
    final runes = text.runes;

    for (int i = 0; i < runes.length; /* empty */ ) {
      int current = runes.elementAt(i);

      // we assume that everything that is not
      // in Extended-ASCII set is an emoji...
      final isEmoji = current > 255;
      final shouldBreak = isEmoji
        ? (x) => x <= 255 
        : (x) => x > 255;

      final chunk = <int>[];
      while (! shouldBreak(current)) {
        chunk.add(current);
        if (++i >= runes.length) break;
        current = runes.elementAt(i);
      }

      children.add(
        TextSpan(
          text: String.fromCharCodes(chunk),
          style: TextStyle(
            fontFamily: isEmoji ? 'EmojiOne' : null,
          ),
        ),
      );
    }

    return TextSpan(children: children);
  } 
}

Which can be used as:

EmojiText(text: 'Hello there: 🧭 🏳️\u200d🌈');

This has the advantage of having the consistent support of Emojis on your app that you can control on different platforms.

The downside is that it will add some MBs to your app.

回答4:

For full emoji compatibility (at least in android, not all emojis are supported in old OS versions) you can use the google free font Noto Color Emoji at https://www.google.com/get/noto/#emoji-zsye-color

Add it to the fonts folder
add in pubspec.yaml

    fonts:
    - family: NotoEmoji
      fonts:
        - asset: fonts/NotoColorEmoji.ttf
          weight: 400

use with TextStyle

Text("🤑", TextStyle(fontFamily: 'NotoEmoji'))

来源：https://stackoverflow.com/questions/44936239/displaying-text-with-emojis-on-flutter

标签

dart

emoji

Flutter