【Flutter -- 进阶】使用字体

前言

有时候要在 Flutter 应用程序中使用不同的字体，就好像会使用 UI 创建的自定义字体，或者可能会使用 Google Flonts 中的字体。在 Flutter 应用程序中使用字体分两步完成：

1. 在pubspec.yaml中声明它们，以确保它们包含在应用程序中
2. 通过TextStyle属性使用字体

1.在 pubsec.yaml 声明字体

name: my_application
description: A new Flutter project.

dependencies:
 flutter:
   sdk: flutter
flutter:

 # The following line ensures that the Material Icons font is
 # included with your application, so that you can use the icons in
 # the material Icons class.
 uses-material-design: true
 fonts:
  - family: NotoSns
    fonts:
      # https://fonts.google.com/specimen/Noto+Sans+TC -->对应字体下载地址 这里可以不填 只是注释
      - asset: fonts/NotoSansTC-Black.otf
  - family: Sriaskdi
    fonts:
      # https://fonts.google.com/specimen/Srisakdi
      - asset: fonts/Srisakdi-Regular.ttf
  - family: NotoSerifTC
    fonts:
      # https://fonts.google.com/specimen/Noto+Serif+TC
      - asset: fonts/NotoSerifTC-Black.ttf

上面格式不能错一点，否则会编译不通过，上面还添加了对应字体的下载地址。把下载好的字体文件放到 fonts 下： family 是字体的名称，可以在TextStyle的fontFamily属性中使用，asset是相对于pubspec.yaml文件的路径，这些文件包含字体中字形的轮廓，在构建应用程序时，这些文件会包含在应用程序的asset包中。 可以给字体设置粗细、倾斜等样式

2. 代码实现

import 'package:flutter/material.dart';

//显示的内容
const String words1 = "Almost before we knew it, we had left the ground.";
const String words2 = "A shining crescent far beneath the flying vessel.";
const String words3 = "A red flair silhouetted the jagged edge of a wing.";
const String words4 = "Mist enveloped the ship three hours out from port.";

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Flutter Fonts',
      theme: new ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: new FontsPage(),
    );
  }
}

class FontsPage extends StatefulWidget {
  @override
  _FontsPageState createState() => new _FontsPageState();
}

class _FontsPageState extends State {
  @override
  Widget build(BuildContext context) {

    // https://fonts.google.com/specimen/Noto+Sans+TC
    var NotoSnsContainer = new Container(
      child: new Column(
        children: [
          new Text(
            "NotoSns",
          ),
          new Text(
            words2,
            textAlign: TextAlign.center,
            style: new TextStyle(
              fontFamily: "NotoSns",-->务必和pubspec.yaml定义的标识对应
              fontSize: 17.0,
            ),
          ),
        ],
      ),
      margin: const EdgeInsets.all(10.0),
      padding: const EdgeInsets.all(10.0),
      decoration: new BoxDecoration(
        color: Colors.grey.shade200,
        borderRadius: new BorderRadius.all(new Radius.circular(5.0)),
      ),
    );


    // https://fonts.google.com/specimen/Noto+Serif+TC
    var NotoSerifTCContainer = new Container(
      child: new Column(
        children: [
          new Text(
            "NotoSerifTC",
          ),
          new Text(
            words3,
            textAlign: TextAlign.center,
            style: new TextStyle(
              fontFamily: "NotoSerifTC",
              fontSize: 25.0,
            ),
          ),
        ],
      ),
      margin: const EdgeInsets.all(10.0),
      padding: const EdgeInsets.all(10.0),
      decoration: new BoxDecoration(
        color: Colors.grey.shade200,
        borderRadius: new BorderRadius.all(new Radius.circular(5.0)),
      ),
    );


    // https://fonts.google.com/specimen/Srisakdi
    var SriaskdiContainer = new Container(
      child: new Column(
        children: [
          new Text(
            "Sriaskdi",
          ),
          new Text(
            words4,
            textAlign: TextAlign.center,
            style: new TextStyle(
              fontFamily: "Sriaskdi",
              fontSize: 25.0,
            ),
          ),
        ],
      ),
      margin: const EdgeInsets.all(10.0),
      padding: const EdgeInsets.all(10.0),
      decoration: new BoxDecoration(
        color: Colors.grey.shade200,
        borderRadius: new BorderRadius.all(new Radius.circular(5.0)),
      ),
    );

    // Material Icons font - included with Material Design
    String icons = "";

    // https://material.io/icons/#ic_accessible
    // accessible:  or 0xE914 or E914
    icons += "\u{E914}";

    // https://material.io/icons/#ic_error
    // error:  or 0xE000 or E000
    icons += "\u{E000}";

    // https://material.io/icons/#ic_fingerprint
    // fingerprint:  or 0xE90D or E90D
    icons += "\u{E90D}";

    // https://material.io/icons/#ic_camera
    // camera:  or 0xE3AF or E3AF
    icons += "\u{E3AF}";

    // https://material.io/icons/#ic_palette
    // palette:  or 0xE40A or E40A
    icons += "\u{E40A}";

    // https://material.io/icons/#ic_tag_faces
    // tag faces:  or 0xE420 or E420
    icons += "\u{E420}";

    // https://material.io/icons/#ic_directions_bike
    // directions bike:  or 0xE52F or E52F
    icons += "\u{E52F}";

    // https://material.io/icons/#ic_airline_seat_recline_extra
    // airline seat recline extra:  or 0xE636 or E636
    icons += "\u{E636}";

    // https://material.io/icons/#ic_beach_access
    // beach access:  or 0xEB3E or EB3E
    icons += "\u{EB3E}";

    // https://material.io/icons/#ic_public
    // public:  or 0xE80B or E80B
    icons += "\u{E80B}";

    // https://material.io/icons/#ic_star
    // star:  or 0xE838 or E838
    icons += "\u{E838}";

    var materialIconsContainer = new Container(
      child: new Column(
        children: [
          new Text(
            "Material Icons",
          ),
          new Text(
            icons,
            textAlign: TextAlign.center,
            style: new TextStyle(
              inherit: false,
              fontFamily: "MaterialIcons",
              color: Colors.black,
              fontStyle: FontStyle.normal,
              fontSize: 25.0,
            ),
          ),
        ],
      ),
      margin: const EdgeInsets.all(10.0),
      padding: const EdgeInsets.all(10.0),
      decoration: new BoxDecoration(
        color: Colors.grey.shade200,
        borderRadius: new BorderRadius.all(new Radius.circular(5.0)),
      ),
    );

    return new Scaffold(
      appBar: new AppBar(
        title: new Text("Fonts"),
      ),
      body: new ListView(
        //主界面
        children: [
          //字体样式一
          NotoSnsContainer,
          //字体样式二
          NotoSerifTCContainer,
          //字体样式三
          SriaskdiContainer,
          //material图标
          materialIconsContainer,
        ],
      ),
    );
  }
}

3. 效果图