flutter_android系统返回到主界面

1.问题:

怎么做到android系统返回到主界面,不退出App呢?

2.解决:

1.android里MainActivity类的代码:

package com.flutter.study_app;

import android.os.Bundle;
import io.flutter.app.FlutterActivity;
import io.flutter.plugin.common.MethodChannel;
import io.flutter.plugins.GeneratedPluginRegistrant;

public class MainActivity extends FlutterActivity {
    //通讯名称,回到手机桌面
    private final String chanel = "android/back/desktop";
    //返回手机桌面事件
    static final String eventBackDesktop = "backDesktop";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        GeneratedPluginRegistrant.registerWith(this);

        initBackTop();
    }

    //注册返回到手机桌面事件
    private void initBackTop() {
        new MethodChannel(getFlutterView(), chanel).setMethodCallHandler(
                (methodCall, result) -> {
                    if (methodCall.method.equals(eventBackDesktop)) {
                        moveTaskToBack(false);
                        result.success(true);
                    }
                }
        );
    }
}

3. flutter代码

import 'package:flutter/services.dart';
import 'package:flutter/material.dart';

class AndroidBackTop {
  ///通讯名称,回到手机桌面
  static const String chanel = "android/back/desktop";

  //返回手机桌面事件
  static const String eventBackDesktop = "backDesktop";

  ///设置回退到手机桌面
  static Future<bool> backDesktop() async {
    final platform = MethodChannel(chanel);
    try {
      await platform.invokeMethod(eventBackDesktop);
    } on PlatformException catch (e) {
      debugPrint(e.toString());
    }
    return Future.value(false);
  }
}

3.使用示例

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:study_app/views/back_desktop/utils/android_back_desktop_util.dart';

class BackDesktop extends StatefulWidget {
  final String title;

  BackDesktop({Key key, this.title}) : super(key: key);

  @override
  _BackDesktopState createState() => new _BackDesktopState();
}

class _BackDesktopState extends State<BackDesktop> {
  int _count = 0;

  void _changeCount() {
    setState(() {
      _count++;
    });
  }

  void _openPage1() {}

  @override
  void dispose() {
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    debugPrint('xxxx');
    // TODO: implement build
    return WillPopScope(
        onWillPop: AndroidBackTop.backDesktop, //重点:页面将要消失时，调用原生的返回桌面方法
        child: new Scaffold(
          appBar: new AppBar(
            title: new Text(widget.title),
          ),
          body: new Center(
              child: new Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              new Text("点击按钮改变数字"),
              new Text("数字" + _count.toString(), style: Theme.of(context).textTheme.display1),
              new FlatButton(
                onPressed: _openPage1,
                child: Text('打开page1'),
                color: Theme.of(context).textSelectionColor,
                highlightColor: Color.fromRGBO(0, 0, 255, .5),
              )
            ],
          )),
          floatingActionButton: new FloatingActionButton(
            onPressed: _changeCount,
            tooltip: '点我改变数字',
            child: new Icon(Icons.add),
            mini: true,
          ),
          floatingActionButtonLocation: FloatingActionButtonLocation.endFloat,
        ));
  }
}

参考:
https://blog.csdn.net/qq_30043669/article/details/84955550