Flutter(Android 混合开发)

前言


Flutter 支持做为 android Moudle 出如今项目中.这样就能够在 已有的项目中 使用.
虽然如今Flutter 比较受关注,可是和weex 同样 ,大部分都只是在观望 不是真正的进行使用.因此 若是用仍是混合开发 原生+Flutter 方式比较合适(自我感受).
写一个demo 进行Android及Flutter 交互.(IOS 方法基本一致).html

Flutter 调用 android 硬件的插件还比较匮乏 好比 各类传感器, 自定义相机 因此就会用到 Flutter 调用android 及android 原生调用 Flutter的方法.java

本例子中会实现.

(1) 原有的android 应用程序嵌入 FlutterView
(2) Flutter 代码调用Android 原生方法进行页面跳转及传值
(3) Android原生 调用 Flutter 方法 进行传值

步骤
新建一个 android 项目android

而后在 同级目录建立一个Flutter Moudlegit

图片.png

而后 导入 Flutter Moudle
Flutter Moudlegithub

Moudle 导入成功后 项目结构
项目结构web

app 目录下的
build.gradle 中 新增了weex

implementation project(':flutter')

项目目录下的
settings.gradle 增长app

setBinding(new Binding([gradle: this]))
evaluate(new File(
  settingsDir.parentFile,
  'flutter_test_module\\.android\\include_flutter.groovy'
))

基础框架就搭建成功了

Demo 实现
实现效果框架

最上层放置了一个 Android原生 TextView 下方使用的FlutterViewjsp

flutterView = Flutter.createView(this, getLifecycle(), "route2");
        FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(FrameLayout.LayoutParams.MATCH_PARENT, FrameLayout.LayoutParams.MATCH_PARENT);
        frameLayout.addView(flutterView, layoutParams);

其中 flutterView = Flutter.createView(this, getLifecycle(), “route2”); route2 与flutter_test_module lib 文件夹下 main.dart 中 所对应 但愿加载 哪一个页面 就填写相应的 route 名称.

Widget _widgetForRoute(String route) {
  switch (route) {
    case 'route1':
      return  MyHomePage(title: 'Flutter Demo Home Page1');
    case 'route2':
      return  MyHomePage(title: 'Flutter Demo Home Page2');
    default:
        return  MyHomePage(title: 'Flutter Demo Home Page2');
  
  }
}

Flutter 调用Android

java

new MethodChannel(flutterView, FlutterToAndroidCHANNEL).setMethodCallHandler(new MethodChannel.MethodCallHandler() {
            @Override
            public void onMethodCall(MethodCall methodCall, MethodChannel.Result result) {

                //接收来自flutter的指令withoutParams
                if (methodCall.method.equals("withoutParams")) {

                    //跳转到指定Activity
                    Intent intent = new Intent(NativeActivity.this, NativeActivity.class);
                    startActivity(intent);

                    //返回给flutter的参数
                    result.success("success");
                }
                //接收来自flutter的指令withParams
                else if (methodCall.method.equals("withParams")) {

                    //解析参数
                    String text = methodCall.argument("flutter");

                    //带参数跳转到指定Activity
                    Intent intent = new Intent(NativeActivity.this, NativeActivity.class);
                    intent.putExtra("test", text);
                    startActivity(intent);

                    //返回给flutter的参数
                    result.success("success");
                } else {
                    result.notImplemented();
                }
            }
        });

dart

Future<Null> _jumpToNative() async {
    String result = await toAndroidPlugin.invokeMethod('withoutParams');

    print(result);
  }


  Future<Null> _jumpToNativeWithParams() async {

    Map<String, String> map = { "flutter": "这是一条来自flutter的参数" };

    String result = await toAndroidPlugin.invokeMethod('withParams', map);

    print(result);
  }

Android 向 Flutter 传参

java

new EventChannel(flutterView, AndroidToFlutterCHANNEL)
                .setStreamHandler(new EventChannel.StreamHandler() {
                    @Override
                    public void onListen(Object o, EventChannel.EventSink eventSink) {
                        String androidParmas = "来自android原生的参数";
                        eventSink.success(androidParmas);
                    }

                    @Override
                    public void onCancel(Object o) {

                    }
                });

dart

void _startfromAndroiPlugin(){
    if(_fromAndroiSub == null){
      _fromAndroiSub =  fromAndroiPlugin.receiveBroadcastStream()
      .listen(_onfromAndroiEvent,onError: _onfromAndroiError);
    }
  }


void _onfromAndroiEvent(Object event) {
    setState(() {
      _nativeParams = event;
    });
  }

  void _onfromAndroiError(Object error) {
    setState(() {
      _nativeParams = "error";
      print(error);
    });
  }

有几处 要注意一一对应
new EventChannel(flutterView, AndroidToFlutterCHANNEL)

new MethodChannel(flutterView, FlutterToAndroidCHANNEL).setMethodCallHandler(new MethodChannel.MethodCallHandler() {
            @Override
            public void onMethodCall(MethodCall methodCall, MethodChannel.Result result) {

                //接收来自flutter的指令withoutParams
                if (methodCall.method.equals("withoutParams")) {

                    //跳转到指定Activity
                    Intent intent = new Intent(NativeActivity.this, NativeActivity.class);
                    startActivity(intent);

                    //返回给flutter的参数
                    result.success("success");
                }
                //接收来自flutter的指令withParams
                else if (methodCall.method.equals("withParams")) {

                    //解析参数
                    String text = methodCall.argument("flutter");

                    //带参数跳转到指定Activity
                    Intent intent = new Intent(NativeActivity.this, NativeActivity.class);
                    intent.putExtra("test", text);
                    startActivity(intent);

                    //返回给flutter的参数
                    result.success("success");
                } else {
                    result.notImplemented();
                }
            }
        });

dart

Future<Null> _jumpToNative() async {
    String result = await toAndroidPlugin.invokeMethod('withoutParams');

    print(result);
  }

  Future<Null> _jumpToNativeWithParams() async {

    Map<String, String> map = { "flutter": "这是一条来自flutter的参数" };

    String result = await toAndroidPlugin.invokeMethod('withParams', map);

    print(result);
  }

Android 向 Flutter 传参

java

new EventChannel(flutterView, AndroidToFlutterCHANNEL)
                .setStreamHandler(new EventChannel.StreamHandler() {
                    @Override
                    public void onListen(Object o, EventChannel.EventSink eventSink) {
                        String androidParmas = "来自android原生的参数";
                        eventSink.success(androidParmas);
                    }

                    @Override
                    public void onCancel(Object o) {

                    }
                });

dart

void _startfromAndroiPlugin(){
    if(_fromAndroiSub == null){
      _fromAndroiSub =  fromAndroiPlugin.receiveBroadcastStream()
      .listen(_onfromAndroiEvent,onError: _onfromAndroiError);
    }
  }

void _onfromAndroiEvent(Object event) {
    setState(() {
      _nativeParams = event;
    });
  }

  void _onfromAndroiError(Object error) {
    setState(() {
      _nativeParams = "error";
      print(error);
    });
  }

有几处 要注意一一对应
public static final String FlutterToAndroidCHANNEL = “com.litngzhe.toandroid/plugin”;
public static final String AndroidToFlutterCHANNEL= “com.litngzhe.toflutter/plugin”;

new EventChannel(flutterView, AndroidToFlutterCHANNEL)
new MethodChannel(flutterView, FlutterToAndroidCHANNEL)

dart中
//获取到插件与原生的交互通道
static const toAndroidPlugin = const MethodChannel(‘com.litngzhe.toandroid/plugin’);

static const fromAndroiPlugin = const EventChannel(‘com.litngzhe.toflutter/plugin’);
MethodChannel 中 涉及到的方法名要要统一

Flutter 布局及路由导航
能够看 胖哥视频
http://jspang.com/post/flutter4.html

本文中 知识点 从下方文章学习
https://www.jianshu.com/p/c5263a3d7aac

本文demo 传至 Github
下载地址