Flutter 开发学习笔记(3):第三方UI库的引入

前言

Flutter已经发布了有10年了，生态也算比较完善了。用于安卓程序开发应该是非常的方便。我们这里就接入一些简单的Flutter的UI即可

初始化程序

我们就用最简单的初始项目即可，保证你的项目能够运行

Icon导入

Flutter是由谷歌开发的跨平台程序，而谷歌本身就有一套自己的UI库，直接使用即可，基本够用了，本体应该有3000多个IOCN。

Material Icon 官方网站

如何导入

比如我们要导入【search】这个ICON，我们就要Icon进行添加。

Icon(Icons.search)

Toast消息提示框引入

在pubspec.yml中添加

dependencies:
  fluttertoast: ^8.2.4

简单封装

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

class ToastUtils {
  static void shotToast(
    String message, [
    //方括号里是可选参数，可以不填，等号右边是默认值
    Toast time = Toast.LENGTH_SHORT,
    ToastGravity gravity = ToastGravity.CENTER,
    Color backColor = Colors.black45,
    Color textColor = Colors.white,
  ]) {
    Fluttertoast.showToast(
        msg: message,
        //消息内容
        toastLength: time,
        //停留时间
        gravity: gravity,
        //出现的位置
        timeInSecForIosWeb: 1,
        backgroundColor: backColor,
        //背景色
        textColor: textColor,
        //前景色
        fontSize: 16.0); //文本字号
  }
}

简单使用

import 'package:flutter/material.dart';
import 'package:fluttertoast/fluttertoast.dart';
import 'utils/ToastUtils.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});


  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    const String appTitle = 'Flutter layout demo';

    return MaterialApp(
      title: appTitle,
      home: Scaffold(
        appBar: AppBar(
          title: const Text(appTitle),
        ),
        body: Center(
          child: ElevatedButton(
              onPressed: () {
                debugPrint('hello flutter');
                ToastUtils.shotToast('hello flutter');
              },
              child: const Text('hello flutter')),
        ),
      ),
    );
  }
}

Charts图表导入

这个直接用官方的即可

【Flutter】图表显示charts_flutter折线图/柱状图/饼状图等

新建pages文件夹存放page

简单代码

import 'dart:math';

import 'package:flutter/material.dart';
import 'package:charts_flutter/flutter.dart' as charts;

class ChartTestPage extends StatelessWidget {

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text("chart_flutter")),
      body: Column(children: [Container(height: 240, child: _simpleLine())]),
    );
  }

  Widget _simpleLine() {
    var random = Random();

    var data = [
      LinearSales(0, random.nextInt(100)),
      LinearSales(1, random.nextInt(100)),
      LinearSales(2, random.nextInt(100)),
      LinearSales(3, random.nextInt(100)),
    ];

    var seriesList = [
      charts.Series<LinearSales, int>(
        id: 'Sales',
        colorFn: (_, __) => charts.MaterialPalette.blue.shadeDefault,
        domainFn: (LinearSales sales, _) => sales.year,
        measureFn: (LinearSales sales, _) => sales.sales,
        data: data,
      )
    ];

    return charts.LineChart(seriesList, animate: true);
  }
}

class LinearSales {
  final int year;
  final int sales;

  LinearSales(this.year, this.sales);
}

实现效果

import 'package:flutter/material.dart';
import 'package:flutter_widget_test/pages/ChartTestPage.dart';
import 'package:fluttertoast/fluttertoast.dart';
import 'utils/ToastUtils.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    const String appTitle = 'Flutter layout demo';

    return MaterialApp(
      title: appTitle,
      home: Scaffold(
        appBar: AppBar(
          title: const Text(appTitle),
        ),
        body: Center(
          child: ElevatedButton(
              onPressed: () {
                debugPrint('hello flutter');
                ToastUtils.shotToast('hello flutter');
              },
              child: ChartTestPage()),
        ),
      ),
    );
  }
}

总结

Flutter 的生态还是可以的，就是教程相对来说比较的晦涩难懂。主要是Dark语法挺C# 的，而且在return里面写一大堆代码，这个我不喜欢。我的代码习惯是先将返回值求出来在放到retrun里面。