通信用到的类
- MethodChannel
- EventChannel
- BasicMessageChannel
MethodChannel使用方式（flutter 调用原生方法）
1. 原生代码
- 定义通信标识
private val METHOD_CHANNEL = "tip.flutter.io/method"
- 创建对象
MethodChannel((getView() as FlutterView), METHOD_CHANNEL).setMethodCallHandler { call, result ->
if (call.method == "getBatteryLevel") {
val ba = getBatteryLevel()
if (ba != -1) {
result.success(ba)
} else {
result.error("UNAVAILABLE", "Battery level not available.", null)
}
} else {
result.notImplemented()
}
}
- 定义原生方法
private fun getBatteryLevel(): Int {
return 123
}
2. dart代码
- 创建对象
static const platfrom = const MethodChannel("tip.flutter.io/method");
- 初始化方法
Future<Null> _getBatteryLevel() async {
String batteryLevel;
try {
final int result = await platfrom.invokeMethod("getBatteryLevel");
batteryLevel = 'Battery level at $result % .';
} on PlatformException catch (e) {
batteryLevel = "Failed to get battery level: '${e.message}'.";
}
setState(() {
_batteryLevel = batteryLevel;
});
}
- 调用方法
@override
void initState() {
// TODO: implement initState
_getBatteryLevel();
super.initState();
}
EventChannel使用方式（主要是native向flutter主动推送数据，例如推送电量，网络状态）
BasicMessageChannel使用方式（native->flutter,flutter->native）
完整nativie 代码如下
package com.gctech.nativeandflutter
import android.os.Bundle
import android.os.Handler
import android.view.View
import android.widget.Toast
import io.flutter.facade.FlutterFragment
import io.flutter.plugin.common.BasicMessageChannel
import io.flutter.plugin.common.EventChannel
import io.flutter.plugin.common.MethodChannel
import io.flutter.plugin.common.StringCodec
import io.flutter.view.FlutterView
import java.util.*
class FlutterBaseFragment : FlutterFragment() {
private val METHOD_CHANNEL = "tip.flutter.io/method"
private val EVENT_CHANNEL = "tip.flutter.io/event"
private val MESSAGE_CHANNEL = "tip.flutter.io/message"
private val handler = Handler()
var mesageChan: BasicMessageChannel<String>? = null
companion object {
fun newInstance(router: String) = FlutterBaseFragment().apply {
arguments = Bundle().apply {
putString("router", router)
}
}
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
MethodChannel((getView() as FlutterView), METHOD_CHANNEL).setMethodCallHandler { call, result ->
if (call.method == "getBatteryLevel") {
val ba = getBatteryLevel()
if (ba != -1) {
result.success(ba)
} else {
result.error("UNAVAILABLE", "Battery level not available.", null)
}
} else {
result.notImplemented()
}
}
EventChannel((getView() as FlutterView), EVENT_CHANNEL).setStreamHandler(object : EventChannel.StreamHandler {
override fun onListen(arguments: Any?, events: EventChannel.EventSink?) {
Timer().schedule(object : TimerTask() {
override fun run() {
handler.post {
events?.success("当前时间毫秒${System.currentTimeMillis()}")
}
}
}, 1000, 1000)
}
override fun onCancel(p0: Any?) {
}
})
mesageChan = BasicMessageChannel<String>(
(getView() as FlutterView),
MESSAGE_CHANNEL,
StringCodec.INSTANCE
)
mesageChan?.setMessageHandler { a, b ->
b.reply("aaaa${System.currentTimeMillis()}")
Toast.makeText(context,a,Toast.LENGTH_LONG).show()
}
}
private fun getBatteryLevel(): Int {
return 123
}
}
完整dart 代码如下
import 'dart:async';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
String _batteryLevel = '';
String _eventStr = '';
String _mssageStr = '_mssageStr';
static const platfrom = const MethodChannel("tip.flutter.io/method");
static const eventChannel = const EventChannel("tip.flutter.io/event");
static const messageChannel = const BasicMessageChannel<String>(
"tip.flutter.io/message", StringCodec());
StreamSubscription _streamSubscripton;
void _incrementCounter() {
setState(() {
_counter++;
});
}
Future<Null> _getBatteryLevel() async {
String batteryLevel;
try {
final int result = await platfrom.invokeMethod("getBatteryLevel");
batteryLevel = 'Battery level at $result % .';
} on PlatformException catch (e) {
batteryLevel = "Failed to get battery level: '${e.message}'.";
}
setState(() {
_batteryLevel = batteryLevel;
});
}
Future<Null> _msssage() async {
messageChannel.setMessageHandler((String message) => Future<String>(() {
print("收到native的消息$message");
setState(() {
_mssageStr = message;
});
return "收到native的消息$message";
}));
String ponse;
try {
ponse = await messageChannel.send("我来自flutter");
} catch (e) {
print(e);
}
setState(() {
_mssageStr = ponse;
});
print(ponse);
}
Future<Null> _lisEvent() async {
String eventStr;
try {
_streamSubscripton = eventChannel
.receiveBroadcastStream()
.listen(_onToDart, onError: _onToDartError);
} on PlatformException catch (e) {
eventStr = "event get data err: '${e.message}'.";
setState(() {
_eventStr = eventStr;
});
}
}
@override
void dispose() {
if (_streamSubscripton != null) {
_streamSubscripton.cancel();
_streamSubscripton = null;
}
// TODO: implement dispose
super.dispose();
}
_onToDart(message) {
setState(() {
_eventStr = message;
});
print(message);
}
_onToDartError(error) {
print(error);
}
@override
void initState() {
// TODO: implement initState
_getBatteryLevel();
_lisEvent();
_msssage();
super.initState();
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'AAA You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.display1,
),
Text(
'$_batteryLevel',
),
Text(
'$_eventStr',
),
Text(
'$_mssageStr',
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
}
c盘
- 修改.gradle 目录
在Windows的环境变量中新建一个环境变量设置，GRADLE_USER_HOME，值为D:\Users\shaowei.gradle，
设置完成之后，点击确定，关闭设置窗口。这个时候可以去AS中看下gradle的用户目录，自动变成了环境变量中的值了
- 修改配置文件Pixel_3_XL_API_28.ini
avd.ini.encoding=UTF-8
path=D:\avd\Pixel_3_XL_API_28.avd
path.rel=avd\Pixel_3_XL_API_28.avd
target=android-28
