関小君刷题记

//初始化，传递1. flutterView（MainActivity中getFlutter获取），2. name常量，Flutter中使用同名常量 
MethodChannel methodChannel = new MethodChannel(flutterView, “testflutter”);

static const methodChannel = const MethodChannel('testflutter');

methodChannel.setMethodCallHandler(_addNativeMethod);

MethodChannel methodChannel = new MethodChannel(flutterView, METHOD_CHANNEL); 
methodChannel.setMethodCallHandler(plugin);

@Override 
public void onMethodCall(MethodCall methodCall, MethodChannel.Result result) { 
  // Flutter调用Native的方法 
  if (methodCall.method.equals("getBatteryLevel")) { 
    int batteryLevel = getBatteryLevel(); 
    if (batteryLevel != -1) { 
      result.success(batteryLevel); 
    } else { 
      result.error("UNAVALIABLE", "battery level unavaliable", null); 
    } 
  } else { 
    result.notImplemented(); 
  } 
} 
//在onMethodCall中监听Flutter调用什么名字的方法（此处getBatterLevel），通过result返回方法的执行结果。

static const methodChannel = const MethodChannel('testflutter');

//方法通道的方法是异步的 
Future<Null> _getBatteryLevel() async { 
  String batteryLevel; 
  try { 
    final int result = await methodChannel.invokeMethod('getBatteryLevel'); 
    batteryLevel = 'Battery level $result .'; 
  } on PlatformException catch (e) { 
    batteryLevel = 'Battery level unknown ${e.message}'; 
  } 
  setState(() { 
    _batteryLevel = batteryLevel; 
  }); 
}

private void sendMessageToFlutter() { 
  if (this.mBasicMessageChannel != null) { 
    this.mBasicMessageChannel.send("Message From Native"); 
  } 
} 

void _listenMessageFromNative() { 
  basicMessageChannel.setMessageHandler(_receiveMessageFromNative); 
}

//Flutter接收Native发来的消息 
Future<dynamic> _receiveMessageFromNative(Object result) async { 
  setState(() { 
    _messageFromNative = result.toString(); 
  }); 
} 

BasicMessageChannel messageChannel = new BasicMessageChannel<>(flutterView, "messageChannel", StandardMessageCodec.INSTANCE); 
messageChannel.setMessageHandler(plugin);

@Override 
public void onMessage(Object o, BasicMessageChannel.Reply reply) { 
  Toast.makeText(mContext, o.toString(), Toast.LENGTH_LONG).show(); 
  reply.reply(o.toString()+" back from native"); 
} 
//reply返回数据给Flutter

static const basicMessageChannel =  
BasicMessageChannel('messageChannel', StandardMessageCodec());

EventChannel eventChannel = new EventChannel(flutterView, EVENT_CHANNEL); 
eventChannel.setStreamHandler(plugin);

@Override 
public void onListen(Object o, EventChannel.EventSink eventSink) { 
  BroadcastReceiver chargingBroadcastReceiver = createChargingBroadcaseReceiver(eventSink); 
  mContext.registerReceiver(chargingBroadcastReceiver,new IntentFilter(Intent.ACTION_BATTERY_CHANGED)); 
} 
@Override 
public void onCancel(Object o) { 
} 
private BroadcastReceiver createChargingBroadcaseReceiver(EventChannel.EventSink eventSink) { 
  return new BroadcastReceiver() { 
    @Override 
    public void onReceive(Context context, Intent intent) { 
      int status = intent.getIntExtra(BatteryManager.EXTRA_STATUS, -1); 
      if (status == BatteryManager.BATTERY_STATUS_UNKNOWN) { 
        eventSink.error("UNAVALIABLE", "charging status is unavailable", null); 
      } else { 
        boolean isCharging = status == BatteryManager.BATTERY_STATUS_CHARGING; 
        eventSink.success(isCharging ? "charging" : "disCharging"); 
      } 
    } 
  }; 
}

static const _eventChannel = const EventChannel('charging');

void listenNativeEvent() { 
  _eventChannel.receiveBroadcastStream().listen(_onEvent, onError: _onError); 
} 
//接收返回的数据 
void _onEvent(Object object) { 
  String s = "Battery is ${object == 'charging' ? '' : 'dis'}Charging"; 
  setState(() { 
    _batteryStatus = s; 
  }); 
}

public class TextViewFactory extends PlatformViewFactory { 
  private MessageCodec<Object> messageCodec; 
  public TextViewFactory(MessageCodec<Object> createArgsCodec) { 
    super(createArgsCodec); 
    this.messageCodec = createArgsCodec; 
  } 
   
  @Override 
  public PlatformView create(Context context, int i, Object o) { 
    return new MyTextview(context, messageCodec, i, (Map<String, Object>) o); 
  } 
}

registrar.platformViewRegistry().registerViewFactory("TextView", new TextViewFactory(new StandardMessageCodec())); 
//起名叫TextView，给Flutter用做viewType

AndroidView( 
  viewType: 'TextView', 
  creationParams: {'text': 'TTTeeeXXXttt'}, 
  creationParamsCodec: new StandardMessageCodec(), 
),//其中creationParams，creationParamsCodec必须同时存在或不存在

new Handler(Looper.getMainLooper()).post(new Runnable() { 
  @Override 
  public void run(){ 
    // call the desired channel message here. 
  } 
})