【Flutter】Flutter 混合开发 ( 关联 Android 工程与 Flutter 工程 | 安卓页面中嵌入 Flutter 页面 | 安卓中启动 Flutter 页面 )（三）

findViewById(R.id.flutter2).setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        Intent intent = FlutterActivity
                .withNewEngine()
                .initialRoute("Android 启动 FlutterActivity")
                .build(MainActivity.this);
        //intent.putExtra("initParams", "Android 中 Activity 启动 Flutter");
        startActivity(intent);
    }
});

package com.example.flutter_native;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.FragmentTransaction;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import io.flutter.embedding.android.FlutterActivity;
import io.flutter.embedding.android.FlutterFragment;
public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.flutter1).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                FragmentTransaction fragmentTransaction =
                        getSupportFragmentManager().beginTransaction();
                // 创建 FlutterFragment
                fragmentTransaction.replace(R.id.frame, FlutterFragment.createDefault());
                fragmentTransaction.commit();
            }
        });
        findViewById(R.id.flutter2).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = FlutterActivity
                        .withNewEngine()
                        .initialRoute("Android 启动 FlutterActivity")
                        .build(MainActivity.this);
                //intent.putExtra("initParams", "Android 中 Activity 启动 Flutter");
                startActivity(intent);
            }
        });
    }
}

import 'package:flutter/material.dart';
import 'dart:ui';
void main() => runApp(
    /// 该构造方法中传入从 Android 中传递来的参数
    MyApp(initParams: window.defaultRouteName,)
);
class MyApp extends StatelessWidget {
  /// 这是从 Android 中传递来的参数
  final String initParams;
  /// 构造方法 , 获取从 Android 中传递来的参数
  const MyApp({Key? key, required this.initParams}):super(key: key);
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: initParams),
    );
  }
}
class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, required this.title}) : super(key: key);
  final String title;
  @override
  _MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;
  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}