Flutter Add to App DEMO 笔记

Posted 2021-05-26 aikongmeng

[GIT地址]
Add to App 官方文档

https://flutter.dev/docs/development/add-to-app

git clone --depth 1  https://github.com/flutter/samples.git

摘录部分代码块，全源码可看上述地址，应该Flutter 已经 出2.0+版本， 增加了空异常检测， 所以demo 所使用的库包都要升级到支持空检查的新版本。
android 端配置:
FlutterActivity 添加到 manifest

  <activity
            android:name="io.flutter.embedding.android.FlutterActivity"
            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
            android:hardwareAccelerated="true"
            android:windowSoftInputMode="adjustResize" />

自定义MyApplication ， 使用 FlutterEngine Cached 的方式使用Flutter页面

public class MyApplication extends Application {
  public FlutterEngine flutterEngine;
  
  @Override
  public void onCreate() {
    super.onCreate();
    // Instantiate a FlutterEngine.
    flutterEngine = new FlutterEngine(this);

    // Start executing Dart code to pre-warm the FlutterEngine.
    flutterEngine.getDartExecutor().executeDartEntrypoint(
      DartEntrypoint.createDefault()
    );

    // Cache the FlutterEngine to be used by FlutterActivity.
    FlutterEngineCache
      .getInstance()
      .put("my_engine_id", flutterEngine);
  }
} 

 Intent intent = FlutterActivity
                .withCachedEngine("my_engine_id")
                .backgroundMode(FlutterActivityLaunchConfigs.BackgroundMode.transparent)
                .build(this);
        startActivity(intent);

channel 配置

 channel = new MethodChannel(flutterEngine.getDartExecutor(), "dev.flutter.example/counter");
        channel.setMethodCallHandler((call, result) -> {
            switch (call.method) {
                case "incrementCounter":
                    count++;
                    reportCounter();
                    break;
                case "requestCounter":
                    count--;
                    reportCounter();
                    break;
            }
        });

channel 注入方法

   private void reportCounter() {
        channel.invokeMethod("reportCounter", count);
    }

Flutter 端代码：

void main() {
  // This call ensures the Flutter binding has been set up before creating the
  // MethodChannel-based model.
  WidgetsFlutterBinding.ensureInitialized();

  final model = CounterModel();

  runApp(
    ChangeNotifierProvider.value(
      value: model,
      child: MyApp(),
    ),
  );
}

_channel 配置方法一一對應

class CounterModel extends ChangeNotifier {
  CounterModel() {
    _channel.setMethodCallHandler(_handleMessage);
    _channel.invokeMethod('requestCounter');
  }

  final _channel = MethodChannel('dev.flutter.example/counter');

  int _count = 0;

  int get count => _count;

  void increment() {
    _channel.invokeMethod('incrementCounter');
  }

  Future<dynamic> _handleMessage(MethodCall call) async {
    if (call.method == 'reportCounter') {
      _count = call.arguments as int;
      notifyListeners();
    }
  }
}

調用

Consumer<CounterModel>(
                  builder: (context, model, child) {
                    return ElevatedButton(
                      onPressed: () => model.increment(),
                      child: Text('Tap me!'),
                    );
                  },
                ),