channel test

lib/battery.dart

+import 'dart:async';
+
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+
+class PlatformChannel extends StatefulWidget {
+  @override
+  _PlatformChannelState createState() => _PlatformChannelState();
+}
+
+class _PlatformChannelState extends State<PlatformChannel> {
+  static const MethodChannel methodChannel =
+      MethodChannel('samples.flutter.io/battery');
+  static const EventChannel eventChannel =
+      EventChannel('samples.flutter.io/charging');
+
+  String _batteryLevel = 'Battery level: unknown.';
+  String _chargingStatus = 'Battery status: unknown.';
+
+  Future<void> _getBatteryLevel() async {
+    String batteryLevel;
+    try {
+      final int result = await methodChannel.invokeMethod('getBatteryLevel');
+      batteryLevel = 'Battery level: $result%.';
+    } on PlatformException {
+      batteryLevel = 'Failed to get battery level.';
+    }
+    setState(() {
+      _batteryLevel = batteryLevel;
+    });
+  }
+
+  @override
+  void initState() {
+    super.initState();
+    eventChannel.receiveBroadcastStream().listen(_onEvent, onError: _onError);
+  }
+
+  void _onEvent(Object event) {
+    setState(() {
+      _chargingStatus =
+          "Battery status: ${event == 'charging' ? '' : 'dis'}charging.";
+    });
+  }
+
+  void _onError(Object error) {
+    setState(() {
+      _chargingStatus = 'Battery status: unknown.';
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Material(
+      child: Column(
+        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
+        children: <Widget>[
+          Column(
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: <Widget>[
+              Text(_batteryLevel, key: const Key('Battery level label')),
+              Padding(
+                padding: const EdgeInsets.all(16.0),
+                child: RaisedButton(
+                  child: const Text('Refresh'),
+                  onPressed: _getBatteryLevel,
+                ),
+              ),
+            ],
+          ),
+          Text(_chargingStatus),
+        ],
+      ),
+    );
+  }
+}

lib/main.dart

 import 'package:flutter/material.dart';
+import 'battery.dart';
 
 void main() => runApp(MyApp());
 
@@ -20,8 +21,15 @@ class MyApp extends StatelessWidget {
         primarySwatch: Colors.blue,
       ),
       home: MyHomePage(title: 'Flutter Demo Home Page'),
+      routes: {
+        "/channeltest": batteryChannelPage,
+      },
     );
   }
+
+  Widget batteryChannelPage(BuildContext context) {
+    return PlatformChannel();
+  }
 }
 
 class MyHomePage extends StatefulWidget {
@@ -97,6 +105,10 @@ class _MyHomePageState extends State<MyHomePage> {
               '$_counter',
               style: Theme.of(context).textTheme.display1,
             ),
+            FlatButton(
+              child: Text('channel test'),
+              onPressed: (){Navigator.pushNamed(context, "/channeltest");},
+            )
           ],
         ),
       ),