Android&Flutter混合开发初体验

最近flutter不是一般的火呀，但对于一些成熟的产品来说，完全摒弃原有App的历史沉淀，全面转向Flutter是不现实的。因此使用Flutter去统一Android、iOS技术栈，把它作为已有原生App的扩展能力，通过有序推进来提升移动端的开发效率
（1）创建flutter模块，创建module后会AS会自动进行flutter的相关配置

（2）将FlutterActivity添加到AndroidManifest.xml

1        <activity
2            android:name="io.flutter.embedding.android.FlutterActivity"
3            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
4            android:hardwareAccelerated="true"
5            android:theme="@style/FlutterTheme"
6            android:windowSoftInputMode="adjustResize" />

（3）跳转到flutter页面

startActivity(FlutterActivity.withNewEngine().initialRoute("route").build(this))

（4）你也可以使用缓存的FlutterEngine，可以减少加载延迟
在MyApplication中实例化一个FlutterEngine

1class MyApplication : Application() {
2   
3   
4    lateinit var flutterEngine: FlutterEngine
5    override fun onCreate() {
6   
7   
8        super.onCreate()
9        flutterEngine = FlutterEngine(this)
10        flutterEngine.dartExecutor.executeDartEntrypoint(DartExecutor.DartEntrypoint.createDefault())
11        FlutterEngineCache.getInstance().put("my_engine_id", flutterEngine)
12    }
13}

然后在Activity中跳转

1        btn.setOnClickListener {
2   
3   
4            startActivity(FlutterActivity.withCachedEngine("my_engine_id").build(this))
5        }

注意：使用withCachedEngine()工厂方法时，请传递与缓存所需的ID相同的ID FlutterEngine

设置缓存引擎时也可以初始路由，修改MyApplication

1        flutterEngine = FlutterEngine(this)
2        flutterEngine.navigationChannel.setInitialRoute("route") //可以借此携带一些字符串数据，可传递到flutter页面
3        flutterEngine.dartExecutor.executeDartEntrypoint(DartExecutor.DartEntrypoint.createDefault())
4        FlutterEngineCache.getInstance().put("my_engine_id", flutterEngine)

对应的dart

1import 'dart:ui';
2import 'package:flutter/material.dart';
3
4void main() => runApp(MyApp());
5
6class MyApp extends StatelessWidget {
7   
8   
9  @override
10  Widget build(BuildContext context) {
11   
12   
13    return MaterialApp(
14      title: 'Flutter Demo',
15      theme: ThemeData(
16        primarySwatch: Colors.blue,
17      ),
18      home: _widgetForRoute(window.defaultRouteName),
19    );
20  }
21}
22
23//路由的选择
24Widget _widgetForRoute(String route) {
25   
26   
27  switch (route) {
28   
29   
30    case 'route':
31      return MaterialApp(
32        home: Scaffold(
33          appBar: AppBar(
34            title: Text('Flutter页面'),
35          ),
36          body: Center(
37            child: Text('行走的猪蹄',
38                style: TextStyle(color: Colors.red),
39                textDirection: TextDirection.ltr),
40          ),
41        ),
42      );
43    default:
44      return Center(
45        child: Text('Unknown route: $route',
46            style: TextStyle(color: Colors.red),
47            textDirection: TextDirection.ltr),
48      );
49  }
50}